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Nutraceuticals in Uro-Oncology: A Structured Expert Review and Precision-Oriented Framework

Nutrients 2026, 18(15), 2411; https://doi.org/10.3390/nu18152411

by Fusun Erten¹

, Ecem Kalemoglu²

, Omer Kucuk^3,*

and Kazim Sahin^4,*

Reviewer 1: Anonymous

Reviewer 2: Anonymous

Reviewer 3: Anonymous

Reviewer 4: Anonymous

Nutrients 2026, 18(15), 2411; https://doi.org/10.3390/nu18152411

Submission received: 17 June 2026 / Revised: 19 July 2026 / Accepted: 20 July 2026 / Published: 23 July 2026

(This article belongs to the Section Nutritional Epidemiology)

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The authors undertake the ambitious task of mapping a wide array of nutraceuticals onto the complex signaling networks of prostate, bladder, renal, and testicular cancers, proposing a precision medicine framework for their future study. The concept is highly novel and potentially very influential in the field of integrative oncology. The review is comprehensive and well-organized, demonstrating a strong command of both the basic and translational literature.

The manuscript is presented as a review but lacks a defined and transparent methodology for literature selection. This is a critical weakness for a review aiming to establish a "precision framework." To be considered a true systematic or scoping review, the authors should outline their search strategy (databases used, search terms, date range), inclusion/exclusion criteria (e.g., types of studies: preclinical, clinical, epidemiological; types of nutraceuticals), and the process for data extraction and synthesis. Without this, the review is an expert opinion piece, which is less persuasive for establishing a rigorous "roadmap." The authors should either:

Conduct and report a formal scoping or systematic review, following established guidelines like PRISMA-ScR. This would greatly strengthen the manuscript's conclusions and provide a transparent evidence base for their framework.

or explicitly reframe the manuscript as a "Perspective," "Opinion," or "Expert Review" piece, clearly stating this in the title and abstract. While this would address the methodological issue, it would diminish the perceived authority of the proposed "precision framework."

The manuscript frequently presents preclinical findings with an enthusiasm that is not always proportionate to their translational potential. The "Evidence Level" and "Best Clinical Setting" columns in Tables 2 and 3 suggest a level of readiness that is not consistently supported by the text. While the authors appropriately note barriers like bioavailability, the overall tone often implies that these compounds are closer to clinical utility than they are. For example, while the section on prostate cancer is nuanced, the ambitious nature of the "clinical settings" proposed (e.g., "adjunct therapy studies") for compounds like curcumin, with extremely poor bioavailability, feels premature. The conclusions should more strongly emphasize the enormous gulf between in vitro mechanisms and human clinical efficacy, stressing that the primary focus of future research must be on fundamental pharmacology (PK/PD) and safety, not efficacy.

The manuscript synthesizes information primarily by summarizing studies sequentially. It falls short of providing a deeper, critical synthesis that identifies and explains conflicting results, highlights significant gaps in the literature, and offers a balanced perspective on the challenges. For instance, the section on soy isoflavones and PCa presents mixed clinical trial data but does not fully analyze the reasons for these discrepancies (e.g., study design, patient selection, formulation, the critical role of equol production). A more analytical approach to these inconsistencies, and the development of hypotheses to explain them, would be valuable. The section on carotenoids and BCa is a better example of critical appraisal.

The review does a good job of mapping pathways but does not fully explore the mechanistic basis for how these pleiotropic compounds achieve their effects. For example, many nutraceuticals are known to activate Nrf2 and/or inhibit NF-κB. The complex interplay between these and other pathways in the context of specific malignancies is not discussed. The article is also weakened by treating each urologic malignancy as a monolithic entity. The authors should explicitly discuss the major molecular subtypes within each cancer (luminal vs. basal vs. neuroendocrine PCa; FGFR3-mutant vs. TP53-mutant bladder cancer; clear-cell vs. papillary vs. chromophobe RCC) and how these different subtypes might be differentially susceptible to, or resistant to, various nutraceutical interventions. This would significantly strengthen the "precision" aspect of the proposed framework.

The field of oncology has been revolutionized by immune checkpoint inhibitors (ICIs). While the TME is mentioned, the manuscript does not adequately discuss the potential for nutraceuticals to modulate the immune system in ways that could interact with ICI therapy. This is a major gap. For example, do these compounds have the potential to enhance anti-tumor immunity or, conversely, to induce immunosuppression? This is a critical area for future research and should be more prominently featured.

The content of Table 2 and Table 3 is significantly overlapping, creating redundancy. The authors should consider merging them into a single, more comprehensive and less repetitive table.

The list of abbreviations in Table 2 is helpful, but many abbreviations (EGCG, UA) are used throughout the text. A global list of abbreviations at the beginning or end of the manuscript would improve readability.

Author Response

REVIEWER 1

Response: We sincerely thank the reviewer for this thoughtful and constructive assessment and for recognizing the novelty, comprehensiveness, and potential influence of the proposed precision-oriented framework. We fully agree that a transparent methodology is essential for distinguishing an evidence-based expert synthesis from an unstructured opinion piece. We considered it methodologically inappropriate to retrospectively relabel the article as a systematic or scoping review. Instead, consistent with the reviewer’s second proposed option, we have explicitly framed the article as a structured expert review in the title, Abstract, and revised Review Methodology section (Section 2). We have also clarified that the proposed framework is conceptual and hypothesis-generating and is intended to define the next scientifically justified research step rather than to represent a formal clinical recommendation, evidence grade, or systematic-review Conclusion. Full database-specific search strategies and final search dates are now provided in Supplementary Tables S1 and S2.

Response: We sincerely thank the reviewer for this important and well-founded criticism. We agree that the original manuscript occasionally used language that could be interpreted as overstating the translational readiness of nutraceutical compounds. We also agree that extensive preclinical pathway modulation, particularly when demonstrated at high in vitro concentrations, should not be presented as evidence that a compound is close to clinical therapeutic use. We have therefore revised the manuscript extensively to distinguish more clearly among mechanistic plausibility, pharmacological feasibility, pharmacodynamic target engagement, and clinical efficacy.

The major revisions are as follows:

The abstract has been rewritten to state explicitly that the available evidence is predominantly preclinical and that many reported effects were obtained at concentrations that may not be achievable in humans. The revised abstract also emphasizes that human efficacy evidence is sparse and that the proposed framework should not be interpreted as an indication of clinical readiness.

A new subsection entitled “2.8.Principles for interpreting translational maturity” has been added. This subsection explains why in vitro pathway modulation cannot be directly extrapolated to human efficacy, particularly in view of extensive metabolism, conjugation, poor bioavailability, and differences between parent compounds and circulating metabolites.

he overlapping mechanistic and translational content of the former Tables 2 and 3 was consolidated into the current Table 3. A separate new Table 2 was added to summarize human evidence only

The original “Evidence Level” column has been replaced with “Current Evidence Base and Translational Maturity.” New columns identify major translational limitations and the immediate research priority. The revised table explicitly states that its categories are descriptive and do not represent clinical recommendation grades.

In Table 3 The original “Best Clinical Setting” column has been removed because we agree that it could imply unjustified clinical readiness. It has been replaced with “Earliest Justifiable Research Step,” and an additional column identifies research approaches that are currently premature.

References to “adjunct therapy studies” have been removed or substantially qualified. For compounds such as curcumin, the revised manuscript now identifies formulation characterization, PK, metabolite analysis, tissue exposure, dose-related safety, and interaction testing as the immediate research priorities. Efficacy-oriented adjunct studies are described as premature.

The prostate cancer section (4.1) has been revised substantially. Curcumin is now used as an example of the difference between extensive network-level activity in experimental systems and limited human pharmacological feasibility. The revised text stresses that nanoparticle or liposomal delivery does not by itself establish clinical readiness and introduces additional formulation-specific safety and disposition questions.

The concluding paragraphs of the prostate, bladder, RCC, and TGCT sections have been rewritten. Each now identifies the next defensible pharmacological research step and explicitly states which forms of clinical efficacy testing would currently be premature.

The integrated perspective has been reframed. The manuscript no longer presents nutraceutical pleiotropy primarily as an advantage. It now recognizes that broad biological activity may also increase the risk of unpredictable pharmacodynamic interactions and therefore creates a ection 5, entitled “Safety and Fundamental Clinical Pharmacology as Prerequisites for Nutraceutical Development,” has been substantially strengthened. In addition, Section 6, entitled “A Pharmacology-First Research Agenda for Nutraceuticals in Uro-Oncology,” and its subsections (Sections 6.1–6.6) now establish a staged development sequence encompassing preparation and analytical characterization, pharmacokinetics and metabolism, safety and interaction assessment, exposure-linked pharmacodynamic evaluation, and, only where justified, efficacy-oriented investigation.

The former precision-trial roadmap has been replaced with a staged pharmacology-first research agenda. This agenda progresses from preparation, characterization, and analytical validation to PK and metabolism, safety and interaction testing, exposure-linked PD assessment, and, only finally, where justified, efficacy-oriented investigation.

The Conclusion has been completely rewritten. It now emphasizes the substantial gulf between in vitro mechanisms and human efficacy and states that few, if any, current nutraceutical candidates satisfy the pharmacological requirements for efficacy-oriented development in uro-oncology.

Overly enthusiastic terminology has been moderated throughout the manuscript. Expressions such as “promising treatment,” “clinical potential,” “optimal clinical setting,” and “suitable for adjunctive use” have been replaced with more accurate terms such as “preclinical rationale,” “translationally immature,” “requires exposure confirmation,” and “not ready for efficacy-oriented testing.”

We agree with the reviewer that the accumulation of additional in vitro mechanisms should not be the primary objective of the field. The revised manuscript now places fundamental pharmacology, PK/PD, metabolite characterization, tissue exposure, safety, and drug–nutraceutical interaction assessment at the center of the proposed research framework.

Response: We thank the reviewer for this valuable comment. We agree that the previous version relied too heavily on sequential study summaries and did not sufficiently address conflicting findings and major evidence gaps. To strengthen the critical synthesis, we added a new section entitled “4.8. Cross-Study Interpretation and Key Evidence Gaps.” This section discusses the potential sources of inconsistency across studies, including differences in formulation, dose, treatment duration, experimental model, patient selection, molecular subtype, metabolic phenotype, microbiome-related biotransformation, and endpoint selection. It also emphasizes the gap between in vitro concentrations and achievable human exposure and explains why negative clinical findings may reflect inadequate exposure or lack of target engagement rather than definitive biological inactivity. In addition, the revised section outlines key priorities for future research, including standardized formulations, quantitative measurement of parent compounds and metabolites, confirmation of target-tissue exposure, and use of predefined pathway-specific pharmacodynamic biomarkers.

Response : We thank the reviewer for this important and constructive comment. We agree that the previous version emphasized pathway mapping but did not sufficiently explain how pleiotropic nutraceuticals may act through interconnected signaling networks or how tumor molecular heterogeneity could modify their effects. To address this concern, we substantially revised Sections 4.1–4.5. We expanded the mechanistic discussion of crosstalk among NRF2, NF-κB, AR, PI3K/AKT/mTOR, MAPK, STAT, HIF, redox regulation, and inflammatory signaling. In particular, we now emphasize the context-dependent role of NRF2. Transient NRF2 activation may protect non-malignant tissues and suppress inflammatory injury, whereas sustained NRF2 activity in established tumors may promote metabolic adaptation, tumor-cell survival, and treatment resistance. Bladder cancer cisplatin resistance is discussed as a specific example of this dual effect.

We also revised the cancer-specific sections to avoid treating each malignancy as a homogeneous entity. The prostate cancer section now distinguishes AR-high luminal, basal-like or lineage-plastic, and neuroendocrine disease. The bladder cancer section discusses FGFR3-enriched luminal tumors, TP53/RB1-altered basal/squamous tumors, and neuroendocrine-like disease. The RCC section differentiates clear-cell, papillary, and chromophobe subtypes, including their distinct hypoxic, metabolic, mitochondrial, and signaling characteristics. Histological and molecular heterogeneity within testicular germ cell tumors is also addressed.

These subtype-specific relationships are presented as biologically justified, testable hypotheses rather than as established clinical recommendations. The revised manuscript now emphasizes that future studies should use molecularly characterized models and link subtype-specific responses to standardized formulations, achievable exposure, target engagement, safety, drug interactions, and sensitivity to standard treatment. We believe these revisions substantially strengthen both the mechanistic depth and the precision-oncology framework of the review.

Response: We thank the reviewer for identifying this important gap. We agree that the previous version mentioned the tumor microenvironment but did not adequately address how nutraceuticals might interact with immune checkpoint inhibitor therapy through immune-stimulatory or immune-suppressive mechanisms. To address this concern, we added a new subsection entitled “4.6.Nutraceutical Modulation of Antitumor Immunity and Potential Interactions with Immune Checkpoint Inhibitors.” The new section discusses how nutraceuticals, dietary interventions, and microbial products may influence dendritic-cell function, antigen presentation, CD8⁺ T-cell activation and infiltration, regulatory T cells, myeloid-derived suppressor cells, tumor-associated macrophages, immunometabolism, and the gut and intratumoral microbiota.

We now summarize preclinical and emerging human evidence indicating that selected interventions may enhance ICI activity. Examples include vitamin E-mediated inhibition of SHP1 in dendritic cells, a defined Lactobacillus-derived exopolysaccharide that promotes CCR6⁺ CD8⁺ T-cell responses, fucoidan- and arginine-associated enhancement of antitumor immunity, and metabolic modulation of the immunologically resistant prostate cancer microenvironment. We also discuss the association between higher dietary fiber intake and improved ICI outcomes. Importantly, the revised section emphasizes that these effects are not uniformly beneficial. Commercial probiotic use has been associated with less favorable ICI outcomes in some settings, and selected plant-derived compounds may suppress T-cell activation or promote regulatory immune phenotypes. Nutraceuticals may also alter immunogenic cell death, immune-related toxicity, drug metabolism, or exposure to concomitant treatments. The revised manuscript therefore presents nutraceutical–ICI interactions as a bidirectional, context-dependent research question rather than an established therapeutic opportunity. We also propose uro-oncology-specific research priorities, including biomarker-rich studies of dendritic-cell activation, CD8⁺/Treg balance, myeloid phenotypes, immune metabolism, microbiota composition, tumor exposure, and immune-related adverse events. We believe this addition substantially strengthens the discussion of the tumor microenvironment and addresses an important translational dimension of the review.

The content of Table 2 and Table 3 is significantly overlapping, creating redundancy. The authors should consider merging them into a single, more comprehensive and less repetitive table.

Response: We thank the reviewer for this helpful observation. The overlapping content of the former Tables 2 and 3 was consolidated into the current Table 3.

Response: We thank the reviewer for this helpful suggestion. To improve readability and ensure consistent terminology throughout the manuscript, we have added a comprehensive global list of abbreviations at the end of the manuscript.

Reviewer 2 Report

Comments and Suggestions for Authors

Comments to the authors: This review addresses an important and interesting topic: the potential role of nutraceuticals in uro oncology, with emphasis on prostate cancer, bladder cancer, renal cell carcinoma, and testicular germ cell tumors. The manuscript presents uro oncologic malignancies as network driven diseases shaped by interconnected signaling pathways, including androgen receptor signaling, receptor tyrosine kinase networks, PI3K AKT mTOR signaling, DNA damage response, inflammatory programs, angiogenesis, and immune microenvironmental regulation. Within this framework, nutraceuticals are proposed as multi target modulators that may influence cancer progression, treatment resistance, and prevention related biology. Also, the review is broad in scope and contains a substantial amount of mechanistic and translational information. Its strongest sections are those connecting prostate cancer and bladder cancer biology with clinically testable settings, such as active surveillance, presurgical intervention windows, urinary exposure assessment, and biomarker based pharmacodynamic evaluation. The manuscript also appropriately recognizes major translational barriers, including limited bioavailability, formulation heterogeneity, variable metabolism, weak clinical evidence, and possible interactions with standard oncologic therapies. Overall, the review has a strong conceptual foundation and could become a useful synthesis for the field. However, the logic would benefit from sharper evidence grading, clearer separation between mechanistic plausibility and clinical benefit, stronger disease specific prioritization, and more operational detail in the proposed precision trial framework. Greater attention to achievable tissue exposure, active metabolites, compound specific biomarkers, and cancer subtype selection would substantially improve the translational rigor of the manuscript. My specific concerns are below: 1: The central logic of the review is attractive but still too broad. The manuscript argues that uro oncology cancers behave as network diseases and that nutraceuticals may therefore be useful because many compounds modulate several signaling hubs at once. This argument needs a sharper causal bridge. Multi target activity does not automatically mean meaningful network control in cancer cells, especially when many reported effects come from high concentration cell culture studies. The review should distinguish direct target engagement from secondary stress responses, and should clarify when a compound truly modulates a disease defining circuit rather than simply altering common cancer readouts such as apoptosis, oxidative stress, or inflammation. 2: The evidence hierarchy is not handled consistently. Epidemiologic associations, animal models, short presurgical studies, cell line experiments, network pharmacology, and clinical outcome trials are often discussed in a similar tone. This weakens the translational logic because each evidence type supports a different level of inference. For example, dietary lycopene intake may support prevention hypotheses, while curcumin or EGCG cell studies mainly support mechanistic plausibility, and small clinical trials mainly support exposure or biomarker feasibility. The review would be stronger if each compound were framed according to a clear evidentiary stage: prevention signal, mechanistic plausibility, pharmacologic feasibility, biomarker activity, or clinical benefit. 3: The disease specific logic is uneven. Prostate cancer and bladder cancer provide relatively coherent translational settings because androgen receptor biology, FGFR enriched urothelial disease, urinary exposure, and presurgical windows can support mechanism based testing. Renal cell carcinoma and testicular germ cell tumors are much less mature contexts. In renal cell carcinoma, the key problem is not only biological plausibility but also interaction with VEGFR directed agents, immune checkpoint therapy, metabolism, and renal clearance. In testicular germ cell tumors, the high cure rate with cisplatin based therapy makes non interference more important than exploratory anticancer activity. The manuscript should avoid presenting all four cancer types as equally suitable for nutraceutical development. 4: Pharmacokinetics and metabolite biology are recognized but not fully integrated into the mechanistic conclusions. The manuscript repeatedly notes poor bioavailability, conjugation, and formulation heterogeneity, but many mechanistic claims still rely on parent compounds tested at concentrations unlikely to be achieved in patients. This creates a logical gap between molecular mechanisms and clinical feasibility. For each major compound class, the review should ask whether relevant parent compounds or active metabolites can reach the prostate, urine, bladder mucosa, kidney tumor tissue, or systemic circulation at biologically meaningful concentrations. Without this exposure logic, pathway claims remain descriptive rather than translational. 5: The proposed precision trial roadmap is conceptually strong but needs more operational specificity. The current roadmap lists many possible biomarkers, including p AKT, p mTOR, p S6, NF kappa B signatures, EMT markers, cleaved caspase 3, cleaved PARP, CD8 infiltration, and PD L1 expression. However, these readouts are not sufficiently matched to specific compounds, tumor genotypes, disease stages, or clinical settings. A stronger logic would define concrete examples: equol producer status and androgen receptor activity in prostate cancer, FGFR3 altered bladder cancer for selected isoflavone hypotheses, urinary exposure plus p AKT or p S6 modulation for bladder studies, and pharmacokinetic safety first designs for renal cell carcinoma. This would move the review from a broad conceptual framework toward a more actionable precision nutraceutical strategy.

Author Response

REVIEWER 2:

Comments and Suggestions for Authors

Response: We thank the reviewer for this important conceptual clarification. We agree that pleiotropic or multi-target activity should not be interpreted automatically as meaningful control of a cancer signaling network. We have therefore substantially refined the central logic of the review.

First, the Introduction now states explicitly that the number of altered pathways or cancer-associated phenotypes does not establish therapeutically relevant network modulation. We define the conditions under which a nutraceutical may be considered a credible network-modulating candidate, including achievable exposure of the parent compound or active metabolite, target-proximal evidence, coherent modulation of a disease-defining circuit, and exclusion of nonspecific cytotoxicity or generalized cellular stress.

Second, the section on translational maturity now distinguishes three mechanistic evidence categories: target-proximal, circuit-level, and downstream phenotypic. Apoptosis, oxidative stress, inflammatory mediators, proliferation, migration, and invasion are now interpreted as downstream responses unless they are causally linked to a defined molecular target and tumor-relevant signaling circuit.

Third, the network-oncology and cancer-specific integration sections have been revised to identify representative disease-defining circuits, including AR–PI3K signaling in prostate cancer, FGFR3/ERBB–PI3K signaling in selected bladder cancer subtypes, VHL–HIF–VEGF signaling in clear-cell renal cell carcinoma, and DNA damage-response or cisplatin-response biology in testicular germ cell tumors. Finally, the pharmacology-first framework now requires concordance among achievable tissue exposure, target engagement, circuit modulation, and downstream phenotype before progression to efficacy-oriented testing. Effects observed only at supraphysiological concentrations or supported solely by common stress, apoptotic, inflammatory, or redox readouts are now classified as hypothesis-generating rather than evidence of clinical readiness. We believe these revisions provide the sharper causal bridge and more rigorous mechanistic distinction requested by the reviewer.

2: The evidence hierarchy is not handled consistently. Epidemiologic associations, animal models, short presurgical studies, cell line experiments, network pharmacology, and clinical outcome trials are often discussed in a similar tone. This weakens the translational logic because each evidence type supports a different level of inference. For example, dietary lycopene intake may support prevention hypotheses, while curcumin or EGCG cell studies mainly support mechanistic plausibility, and small clinical trials mainly support exposure or biomarker feasibility. The review would be stronger if each compound were framed according to a clear evidentiary stage: prevention signal, mechanistic plausibility, pharmacologic feasibility, biomarker activity, or clinical benefit.

Response: We thank the reviewer for identifying this important inconsistency. We agree that the previous version did not sufficiently distinguish the level of inference supported by epidemiological, computational, experimental, pharmacokinetic, presurgical, and clinical-outcome evidence. We have therefore substantially revised the evidence-classification framework and standardized its application throughout the manuscript. First, Section “2.8. Principles for Interpreting Translational Maturity,” has been revised to define five explicit evidentiary stages: Stage 1, prevention signal; Stage 2, mechanistic plausibility; Stage 3, pharmacologic feasibility; Stage 4, exposure-linked biomarker activity; and Stage 5, clinical benefit. Stage assignment is now made for each compound–cancer–formulation context rather than for a compound in isolation. We also clarify that evidence from an earlier stage cannot be used to infer a later-stage conclusion. Second, we now distinguish the inferences supported by different study designs. Human dietary and observational associations are interpreted as prevention signals but not as evidence of causality or therapeutic efficacy. In vitro, ex vivo, organoid, animal, and experimentally unvalidated network-pharmacology studies are interpreted as mechanistic plausibility. Network pharmacology predictions are explicitly described as hypothesis-generating rather than as evidence of direct target engagement. Human pharmacokinetic, active-metabolite, tissue-distribution, tolerability, and interaction studies support pharmacologic feasibility. Presurgical studies are classified as exposure-linked biomarker activity only when verified exposure is associated with a prespecified, disease- and compound-matched pharmacodynamic endpoint. Only controlled studies demonstrating improvement in validated clinical outcomes are considered evidence of clinical benefit. Third, Table 2 has been revised to include a “Highest Supported Evidentiary Stage” column for each cancer–compound context, together with the exposure species to be verified, matched pharmacodynamic biomarkers, principal limitations, and the earliest scientifically justified research step. The table footnote now explicitly states that clinical enrollment, tissue availability, or nonspecific biomarker changes do not establish clinical benefit. Fourth, the terminology used throughout the disease-specific sections has been standardized. Finally, the Abstract, pharmacology-first roadmap, tables, disease-specific sections, and Conclusion now state explicitly that most of the evidence is concentrated within Stages 1 and 2, that Stage 3–4 evidence remains limited and formulation-dependent, and that no nutraceutical discussed in this review has established Stage 5 clinical benefit for uro-oncologic treatment. We believe these changes provide a more consistent and transparent translational hierarchy and directly address the reviewer’s concern.

3: The disease specific logic is uneven. Prostate cancer and bladder cancer provide relatively coherent translational settings because androgen receptor biology, FGFR enriched urothelial disease, urinary exposure, and presurgical windows can support mechanism based testing. Renal cell carcinoma and testicular germ cell tumors are much less mature contexts. In renal cell carcinoma, the key problem is not only biological plausibility but also interaction with VEGFR directed agents, immune checkpoint therapy, metabolism, and renal clearance. In testicular germ cell tumors, the high cure rate with cisplatin based therapy makes non interference more important than exploratory anticancer activity. The manuscript should avoid presenting all four cancer types as equally suitable for nutraceutical development.

Response: We thank the reviewer for this important disease-specific clarification. We agree that the four uro-oncologic malignancies should not be presented as equally suitable settings for nutraceutical development. We have therefore revised the manuscript to establish an explicit hierarchy of translational tractability and to define a distinct governing development principle for each malignancy.

The Abstract and the opening of the cancer-specific integration section now state that PCa and BCa currently provide the most tractable settings for early translational investigation. In PCa, this relative advantage is based on AR-centered disease biology and the availability of active-surveillance and presurgical windows in which prostate exposure, target engagement, and pathway-specific pharmacodynamic responses can be evaluated. We also clarify that AR-directed effects must be distinguished from nonspecific cytotoxicity through molecularly appropriate AR-positive and AR-negative models. In BCa, FGFR/RTK-defined subgroups, urinary sampling, and pre-TURBT or peri-cystectomy tissue access provide opportunities for exposure-linked biomarker studies. These features are now described as supporting pharmacologic and biomarker investigation rather than established clinical efficacy.

The RCC section has been revised to emphasize that RCC is an interaction-first and safety-first setting rather than a direct efficacy-development opportunity. The revised text prioritizes formulation-specific pharmacokinetics, characterization of active metabolites, renal and hepatic disposition, and formal interaction assessment with VEGFR-directed TKIs, immune checkpoint inhibitors, mTOR-directed agents, and other systemic treatments. Tumor-directed biomarker investigation is proposed only after pharmacologic compatibility with the relevant standard regimen has been established.

The TGCT section has been substantially reframed around the principle of non-interference. Because cisplatin-based therapy is frequently curative, the revised manuscript states that any proposed supportive or adjunctive nutraceutical must first be shown not to reduce cisplatin exposure, DNA-damage signaling, or tumor cytotoxicity. Protection against renal, neural, reproductive, or other toxicities must also be demonstrated to be tumor-selective before clinical investigation is considered. Exploratory anticancer activity is therefore no longer presented as the principal translational objective in TGCT.

Finally, the integrated perspective, Table 2, and the Conclusion now explicitly distinguish mechanism- and biomarker-led development in PCa and BCa from interaction-led development in RCC and non-interference-led evaluation in TGCT. We believe these revisions provide a more clinically realistic disease-specific hierarchy and directly address the reviewer’s concern.

4: Pharmacokinetics and metabolite biology are recognized but not fully integrated into the mechanistic conclusions. The manuscript repeatedly notes poor bioavailability, conjugation, and formulation heterogeneity, but many mechanistic claims still rely on parent compounds tested at concentrations unlikely to be achieved in patients. This creates a logical gap between molecular mechanisms and clinical feasibility. For each major compound class, the review should ask whether relevant parent compounds or active metabolites can reach the prostate, urine, bladder mucosa, kidney tumor tissue, or systemic circulation at biologically meaningful concentrations. Without this exposure logic, pathway claims remain descriptive rather than translational.

Response: We thank the reviewer for identifying this important gap between pathway-based interpretation and clinical pharmacology. We agree that poor bioavailability and metabolism should not be treated merely as general limitations but should be incorporated directly into the mechanistic conclusions for each compound–cancer–formulation context. We have therefore added a new subsection entitled “Exposure, Metabolite Identity, and Compartment-Specific Plausibility.” This section introduces an exposure–species–compartment framework that asks four questions for each candidate: which chemical species predominate after administration; whether the parent compound or relevant metabolites reach the biological compartment of interest; whether measured concentrations overlap with those required for the proposed effect; and whether formulation- and patient-dependent variability has been characterized. Mechanistic findings obtained only with supraphysiological concentrations of unconjugated parent compounds are now classified as hypothesis-generating unless supported by achievable target-site exposure or activity of the predominant human metabolite.

The PCa section has been revised to incorporate human prostate-tissue pharmacokinetic evidence. In particular, the study by Cai et al. (2021) is now used to show that total resveratrol-derived material reaches human prostate tissue, whereas unconjugated resveratrol is undetectable and sulfate and glucuronide metabolites predominate. Resveratrol pathway claims are therefore qualified according to the activity and uptake of these tissue-relevant metabolites. The study by Henning et al. (2020) is used to distinguish detection of EGCG, ECG, quercetin, and related species in human prostate tissue from evidence of pharmacodynamic activity. Isoflavone interpretation now incorporates equol-producer status, while pomegranate and flavone discussions have been reframed around urolithin, methylated, and glucuronidated metabolite biology.

The BCa section now distinguishes urinary excretion and luminal exposure from bladder-mucosal or intratumoral uptake. Timed urinary measurements are proposed together with paired TURBT or cystectomy tissue sampling, because urinary detection alone does not establish intracellular tumor exposure or target engagement. The RCC section similarly clarifies that urinary concentration is not a universal surrogate for renal-tumor exposure. Based on the multi-matrix findings of Ganti et al. (2012) and Nizioł et al. (2018), paired plasma or serum, urine, tumor, and adjacent kidney measurements are now recommended. The TGCT section has also been revised to require simultaneous characterization of nutraceutical-derived species and cisplatin pharmacokinetics before supportive or adjunctive investigation.

In addition, we have added a new table summarizing the predominant exposure-relevant species, target compartments, available tissue evidence, principal pharmacokinetic–mechanistic gaps, and required next studies for the major nutraceutical classes. The pharmacology-first research agenda and Conclusion have been revised to require concordance among preparation identity, parent-compound and metabolite exposure, target-compartment concentration, target engagement, and pharmacodynamic response. Finally, pathway statements throughout the manuscript have been qualified to distinguish activity of unconjugated parent compounds in experimental systems from exposure-compatible activity of the chemical species that predominate in humans. We believe these changes close the logical gap identified by the reviewer and transform pharmacokinetics and metabolite biology from general limitations into explicit determinants of mechanistic and translational interpretation.

5: The proposed precision trial roadmap is conceptually strong but needs more operational specificity. The current roadmap lists many possible biomarkers, including p AKT, p mTOR, p S6, NF kappa B signatures, EMT markers, cleaved caspase 3, cleaved PARP, CD8 infiltration, and PD L1 expression. However, these readouts are not sufficiently matched to specific compounds, tumor genotypes, disease stages, or clinical settings. A stronger logic would define concrete examples: equol producer status and androgen receptor activity in prostate cancer, FGFR3 altered bladder cancer for selected isoflavone hypotheses, urinary exposure plus p AKT or p S6 modulation for bladder studies, and pharmacokinetic safety first designs for renal cell carcinoma. This would move the review from a broad conceptual framework toward a more actionable precision nutraceutical strategy.

Response: We thank the reviewer for this important recommendation. We agree that the previous roadmap presented a broad list of potentially relevant biomarkers without sufficiently specifying how individual readouts should be matched to a compound, tumor genotype, exposure compartment, disease stage, and clinical setting. We have therefore revised the roadmap using a compound–subtype–compartment–readout framework.

First, the revised roadmap now requires each study to prespecify a chemically characterized intervention, molecular or metabolic eligibility criteria, the compartment in which the parent compound and active metabolites will be measured, one primary target-proximal or circuit-level pharmacodynamic endpoint, and explicit go/no-go criteria. General apoptotic, inflammatory, redox, EMT, and immune markers are now treated as secondary endpoints unless they are directly linked to the proposed mechanism.

Second, the PCa section now provides an operational isoflavone example combining prospectively defined equol-producer status, measured serum, urinary, and prostate-tissue S-equol exposure, baseline AR activity, and a tissue AR-transcriptional endpoint. p-AKT or p-S6 is proposed only for PTEN-deficient or PI3K-active tumors. Serum PSA alone is no longer considered sufficient evidence of AR target engagement.

Third, the BCa section now proposes genotype–exposure–pathway matching. For selected isoflavone hypotheses in FGFR3-altered disease, FGFR3 status is combined with timed urinary and bladder-tissue exposure and p-AKT or p-S6 modulation when PI3K/mTOR signaling is the prespecified mechanism. A separate luteolin-like mTOR hypothesis prioritizes p-S6, with p21 as a mechanism-specific secondary endpoint, only after urinary and tissue exposure has been demonstrated.

Fourth, RCC has been reframed as a pharmacokinetic safety-first setting. The initial study sequence now prioritizes dose escalation, tolerability, parent-compound and metabolite pharmacokinetics, renal and hepatic disposition, and interaction with the specified VEGFR-, mTOR-, or immune-directed regimen. Tumor pharmacodynamic biomarkers are introduced only in a subsequent histology- and regimen-specific expansion cohort after adequate exposure and absence of clinically meaningful treatment interaction have been established.

We have also added an operational trial matrix summarizing the candidate hypothesis, eligibility criteria, exposure measurements, primary pharmacodynamic endpoint, and go/no-go requirement for representative PCa, BCa, RCC, and TGCT settings. We believe these revisions convert the previous broad biomarker framework into a more actionable and testable precision nutraceutical development strategy.

Reviewer 3 Report

Comments and Suggestions for Authors

Dear Authors,

Your manuscript addresses a timely and potentially useful topic by linking nutraceuticals with major uro-oncologic signaling networks, including prostate, bladder, renal, and testicular malignancies. Its strongest element is the attempt to move beyond generic antioxidant narratives and to frame nutraceuticals as exposure-verified, biomarker-guided adjuncts rather than empirical supplements. However, in its current form the review remains too narrative and insufficiently methodologically transparent for a high-quality review article in Nutrients. The discussion is often mechanistically rich but clinically under-weighted, and the distinction between in vitro plausibility, animal evidence, observational data, and human interventional evidence is not consistently sharp enough. The article could become publishable after substantial revision, but the authors should strengthen the methodological foundation, rebalance the clinical evidence, and make the figures/tables more rigorous and less schematic.

Major comments:

– The review methodology needs to be added or substantially clarified. Even if this is intended as a narrative or state-of-the-art review rather than a systematic review, the authors should report databases searched, search dates, core search terms, inclusion/exclusion logic, how clinical versus preclinical studies were prioritized, and how evidence was selected for the tables. Without this, the evidence synthesis is not reproducible.

– The evidence hierarchy should be made much clearer. Please add a dedicated table summarizing human evidence by cancer type and compound/class, including formulation, dose, duration, study design, population, endpoints, pharmacokinetic or tissue-exposure data, biomarker outcomes, clinical findings, and safety signals. This is essential because many claims are supported mainly by preclinical or mechanistic studies.

– The manuscript should more explicitly separate mechanistic plausibility from clinical applicability. Statements suggesting therapeutic opportunity should be tempered where evidence is limited, particularly for RCC and TGCT. For testicular germ cell tumors, where curability with cisplatin-based treatment is high, the manuscript should emphasize safety and non-interference with curative therapy rather than exploratory nutraceutical modulation.

– The “precision framework” is conceptually attractive but currently remains too general. Please convert it into a practical, disease-specific roadmap: which molecular subtype, which nutraceutical/formulation, which exposure marker, which pharmacodynamic biomarker, which clinical setting, and which endpoint would be appropriate for PCa, BCa, RCC, and TGCT.

– The pharmacology and safety section should be strengthened. Please discuss specific interaction mechanisms relevant to oncology practice, including CYP enzymes, UGT metabolism, P-gp/BCRP transporters, VEGFR TKIs, AR-pathway inhibitors, taxanes, cisplatin-based chemotherapy, PARP inhibitors, and immune checkpoint inhibitors. The current discussion correctly notes interaction risk but should become more actionable.

– Several figures and tables require revision. The figures are visually attractive but sometimes oversimplify the evidence and may imply stronger clinical relevance than is justified. Figure 4 should be aligned with its caption and disease scope, while Figure 5 should avoid product-like supplement imagery. Please also clarify whether any figures were AI-generated or adapted from other sources and ensure that permissions/source statements are complete.

– Table 2 uses qualitative evidence levels, but the criteria behind these categories are not sufficiently operational. Please define exactly what qualifies as “strong preclinical,” “limited clinical,” “moderate,” or “clinical absent,” and apply these categories consistently across all compounds.

Minor comments:

– Please reduce repetition across the sections on PI3K/AKT/mTOR, NF-κB, EMT, bioavailability, and biomarker-driven trials.

– Standardize terminology and spelling throughout, including “signaling/signalling,” “uro-oncologic/uro-oncology,” and compound class names.

– Please distinguish clearly between dietary exposure, food-derived intake, purified nutraceuticals, and pharmaceutical-grade formulations.

– Correct citation formatting issues where references are attached directly to words without a space, e.g., “reside[...],” “programs[...],” and similar cases.

– Remove duplicate or template-like formatting elements, including the repeated “References” heading and remaining placeholder journal metadata.

– Please verify that all references cited in the tables are cited accurately and that all cited references are present in the reference list.

– The author contribution statement should be checked for appropriateness; “software” is listed despite the manuscript being a narrative review, and its meaning should be clarified if retained.

– The English is generally understandable, but the manuscript would benefit from condensation and editing to reduce overly formulaic, repetitive, and long sentences.

Please provide a detailed point-by-point response to all comments and indicate clearly where each revision has been made in the manuscript.

Best regards,

The reviewer.

Author Response

REVIEWER 3:

Comments and Suggestions for Authors

Major comments:

Response: The review methodology has now been substantially expanded and clarified in a dedicated Review Methodology section (Section 2). Specifically, the revised manuscript now reports the databases searched (PubMed/MEDLINE, Scopus, Web of Science Core Collection, and Embase), the search period (from database inception to 17 June 2026), the core search domains and representative search terms, the eligibility and exclusion logic, the study selection and prioritization approach for clinical versus preclinical evidence, and the prespecified criteria used for table construction. We also clarify that this article was conducted as a structured expert review rather than a systematic review, and we explicitly describe how evidence was categorized into translational domains and mapped across the review’s evidence hierarchy. In addition, full database-specific search strings are now referenced in Supplementary Tables S1 and S2

Response: We thank the reviewer for this important recommendation. We agree that the previous version did not sufficiently distinguish the extensive preclinical literature from the more limited human evidence.

We have therefore added a dedicated subsection, “2.7.Human Evidence Summary and Evidence Hierarchy,” together with a new main-text table summarizing only human studies. The table is organized by cancer type and compound/class and includes formulation, dose, duration, study design, population, endpoints, pharmacokinetic or tissue-exposure data, biomarker outcomes, clinical findings, safety signals, and the highest supported translational inference.

Response: We thank the reviewer for this important recommendation. We agree that mechanistic plausibility should be clearly distinguished from clinical applicability, particularly in RCC and TGCT, where human evidence remains limited..

To address this concern, we added Section 4.5, entitled “Mechanistic Plausibility versus Clinical Applicability in RCC and TGCT,” and revised the corresponding discussions in Sections 4.3 and 4.4. The revised text clarifies that evidence for nutraceuticals in RCC is derived predominantly from cell-culture and animal studies. Reported effects on VHL–HIF–VEGF, PI3K/AKT/mTOR, NF-κB, STAT, MAPK, apoptosis, angiogenesis, and treatment sensitivity are therefore presented as mechanistic rationale rather than evidence of therapeutic efficacy or clinical readiness. We further emphasize that clinical investigation in RCC should initially prioritize formulation-specific pharmacokinetics, renal and tumor-tissue exposure, safety, and formal interaction testing with VEGFR-directed therapies, mTOR inhibitors, and immune checkpoint inhibitors.

The TGCT discussion has been revised more conservatively. Because cisplatin-based treatment is frequently curative, we now identify safety and preservation of established treatment efficacy as the primary translational requirements. Preclinical findings concerning protection against cisplatin-associated testicular injury are no longer presented as evidence of clinical applicability. Instead, we emphasize that any proposed intervention must first demonstrate non-interference with cisplatin pharmacokinetics, platinum–DNA adduct formation, DNA-damage signaling, apoptosis, and tumor-cell killing.

We also revised the RCC and TGCT entries in the translational evidence table and tempered statements throughout the manuscript that could imply therapeutic readiness. RCC is now characterized as mechanistically promising but clinically premature, whereas TGCT is framed within a safety- and non-interference-first research strategy. No nutraceutical is presented as a clinically established adjunct in either malignancy.

Response: We thank the reviewer for this constructive recommendation. We agree that the previous precision framework described the general principles of formulation, exposure, biomarker selection, and disease context but did not translate them into sufficiently specific development pathways.

We have therefore added a new subsection entitled “6.5. A Practical Disease-Specific Precision Roadmap” and a dedicated table specifying, for each malignancy, a molecular context, candidate nutraceutical or formulation, exposure marker, primary pharmacodynamic biomarker, initial clinical setting, and early-stage endpoint.

For prostate cancer, the revised roadmap proposes standardized green tea catechins in AR-driven, PTEN-deficient localized disease, with plasma and prostate-tissue exposure measurements and tissue p-S6 as a mechanism-linked endpoint in active-surveillance or presurgical studies. For bladder cancer, it identifies FGFR3-altered luminal-papillary NMIBC as a tractable setting for a standardized isoflavone formulation, with urinary and tissue exposure and an FGFR3-linked p-ERK or p-AKT endpoint in a pre-TURBT window.

For clear-cell RCC, the roadmap remains deliberately conservative and prioritizes formulation-specific pharmacokinetics, renal and tumor exposure, interaction testing, and HIF/VEGF- or mTOR-linked biomarker modulation in a presurgical setting before any efficacy-oriented combination study. For TGCT, no nutraceutical is presented as clinically ready. The roadmap instead requires prior cisplatin non-interference data and prioritizes preservation of cisplatin pharmacokinetics, platinum–DNA adduct formation, DNA-damage signaling, dose intensity, and tumor response.

We have also clarified that each early trial should evaluate one molecular context, one standardized formulation, one principal exposure marker, one primary mechanism-matched pharmacodynamic biomarker, and one clinical objective. The proposed roadmap is presented as a set of stage-appropriate research examples rather than clinical recommendations.

Response: We thank the reviewer for this important and clinically relevant recommendation. We agree that the previous version identified the general possibility of drug–nutraceutical interactions but did not adequately distinguish metabolic, transporter-mediated, immunological, and treatment-specific risks. We have therefore substantially revised Section 6.3, now entitled “Safety and Clinically Relevant Interaction Assessment.” The revised section separately discusses CYP-mediated oxidation, UGT-dependent glucuronidation, and P-gp/BCRP transporter effects. It also explains that interaction risk may reflect the combined effects of phase I metabolism, conjugation, and transporter regulation rather than a single isolated mechanism. Treatment-specific subsections have been added for VEGFR-directed TKIs, AR-pathway inhibitors, taxanes, cisplatin-based chemotherapy, PARP inhibitors, and immune checkpoint inhibitors. For each treatment class, we now describe the principal interaction mechanisms, potential pharmacokinetic or pharmacodynamic consequences, overlapping toxicities, and recommended monitoring or avoidance strategies. We additionally distinguish classical metabolic interactions from the immunological interactions relevant to checkpoint inhibition and emphasize the need to demonstrate non-interference with cisplatin-based curative treatment in testicular germ cell tumors. A new table has also been added summarizing the major interaction vulnerabilities, potential clinical consequences, and practical safeguards for each treatment context. Finally, the revised section recommends documentation of the exact nutraceutical preparation, structured medication and supplement reconciliation, oncology-pharmacist review, prospective pharmacokinetic evaluation, predefined safety monitoring, and explicit stopping criteria when combinations are investigated. These changes make the pharmacology and safety discussion more specific and actionable while avoiding the assumption that in vitro enzyme or transporter findings necessarily represent clinically significant interactions.

Response: We thank the reviewer for this careful and constructive assessment. We agree that some of the original figures visually condensed mechanistic and translational evidence in a manner that could be interpreted as implying greater clinical maturity than is supported by the literature.

Figure 4 has been redesigned to focus exclusively on lycopene-related evidence in prostate cancer, consistent with its location and caption. The bladder cancer, renal cell carcinoma, and testicular germ cell tumor elements have been removed. The revised figure now distinguishes preclinical mechanistic findings from human dietary, exposure, and prevention-related evidence and explicitly states that clinical therapeutic benefit has not been established.

Figure 5 has also been redesigned. The supplement-bottle image has been removed and replaced with neutral chemical-structure and pathway-based representations of curcumin and ursolic acid. The figure now identifies the illustrated effects as predominantly preclinical and states that urinary or urothelial exposure, target engagement, treatment interactions, and clinical benefit remain insufficiently established. The revised figure does not depict or endorse a commercial supplement product.

To reduce oversimplification across the manuscript, the figure legends and relevant table footnotes have been revised to distinguish mechanistic plausibility, human exposure, pharmacodynamic activity, and clinical benefit. Statements that could imply therapeutic efficacy have been replaced with evidence-qualified language, and a common clarification has been added indicating that pathway effects are predominantly preclinical unless otherwise specified.

Figures 1–5 were created by the authors using BioRender.com under an appropriate publication license. Added to Acknowledgments section. No figure was adapted or reproduced from previously published material. No generative artificial intelligence tool was used in figure preparation

Response: We thank the reviewer for this helpful comment. Table 2 and its footnote have been revised to define the evidence categories more explicitly and apply them consistently. The categories now distinguish preclinical evidence, limited human exposure or biomarker evidence, moderate translational evidence, and absence of controlled clinical-benefit data. We also clarified that these categories are descriptive and not recommendation grades.

Minor comments:

– Please reduce repetition across the sections on PI3K/AKT/mTOR, NF-κB, EMT, bioavailability, and biomarker-driven trials.

Response: We thank the reviewer for this comment. Repetitive descriptions of PI3K/AKT/mTOR, NF-κB, EMT, bioavailability, and biomarker-driven trial requirements were condensed and consolidated into the general translational framework. Cancer-specific sections were revised to emphasize only disease-specific interpretation.

– Standardize terminology and spelling throughout, including “signaling/signalling,” “uro-oncologic/uro-oncology,” and compound class names.

Response: Terminology and spelling were standardized throughout the manuscript. American English spelling, including “signaling,” is now used consistently, while “uro-oncology” and “urologic malignancies” are used according to context. Compound-class names and abbreviations were also standardized.

– Please distinguish clearly between dietary exposure, food-derived intake, purified nutraceuticals, and pharmaceutical-grade formulations.

Response: We clarified the distinction among habitual dietary exposure, food-derived intake, purified nutraceuticals, and pharmaceutical-grade formulations. We also stated that evidence from these exposure categories should not be considered interchangeable because they differ in dose, composition, metabolism, and bioavailability.

– Correct citation formatting issues where references are attached directly to words without a space, e.g., “reside[...],” “programs[...],” and similar cases.

Response: Citation formatting was checked throughout the manuscript. Missing spaces between text and citations were corrected, and punctuation surrounding references was standardized.

– Remove duplicate or template-like formatting elements, including the repeated “References” heading and remaining placeholder journal metadata.

Response: Duplicate headings and residual template elements were removed. Placeholder journal metadata and draft-formatting elements were also deleted from the revised manuscript.

– Please verify that all references cited in the tables are cited accurately and that all cited references are present in the reference list.

Response: All references cited in the tables were checked against the original publications and the reference list. Duplicate entries were removed, and the accuracy and relevance of table citations were verified.

– The author contribution statement should be checked for appropriateness; “software” is listed despite the manuscript being a narrative review, and its meaning should be clarified if retained.

Response: The Author Contributions statement was revised. Because no software was developed for this review, the “software” contribution was removed and replaced with contribution categories appropriate for literature review and data curation.

– The English is generally understandable, but the manuscript would benefit from condensation and editing to reduce overly formulaic, repetitive, and long sentences.

Response: The manuscript underwent language and structural editing. Long and formulaic sentences were shortened, repeated statements were removed, and readability, punctuation, and sentence structure were improved throughout.

Reviewer 4 Report

Comments and Suggestions for Authors

The manuscript has the following issues that merit further consideration.

Overall positioning of the manuscript

The overall positioning of the manuscript should be reconsidered. Natural nutraceuticals/health products may claim to regulate physiological functions or supplement nutrition, but they should not claim to treat diseases. Their functional positioning should emphasize health-promoting effects, such as immune support, antioxidant activity, or potential supportive effects, rather than therapeutic efficacy against tumors.

For example, the current title of Figure 1 is “Core signaling hubs and therapeutic nodes in uro-oncology.” It may be more appropriate to revise it as: “Core signaling hubs potentially modulated by plant-derived nutraceuticals in uro-oncology.” Similar issues may also exist elsewhere in the manuscript. The authors are advised to review the entire manuscript carefully and revise the wording accordingly.

Other issues

In Figure 1, the arrows should not overlap with other boxes, as this makes the figure appear cluttered. The authors are advised to revise the layout. In addition, the figure legend does not mention the central “Inflammation” module or the lower-left “Phenotypic outputs” module.
For the legend of Figure 2, it is recommended that the authors use more cautious wording, such as “preclinical studies suggest,” “possible mechanisms,” and “some studies have shown.” The statement regarding reduced PSA levels should be restricted to prostate cancer models. Otherwise, readers may be misled into thinking that these flavonols have already demonstrated established clinical anticancer efficacy. The legend states: “In vivo, flavonols reduce tumor size and PSA levels. In prostate cancer, they downregulate AR signaling, while in bladder cancer, they inhibit proliferation and invasion, with enhanced efficacy in combination therapy.” However, the figure itself does not clearly distinguish between in vitro and in vivo evidence. In addition, the purple and yellow boxes in the lower-right part of Figure 2 contain similar information and should be merged to make the expression more precise and easier for readers to understand.
In the upper-right part of Figure 3, it may be preferable to remove the text “EGCG” and instead insert the chemical structure of EGCG. This would correspond better to the soy isoflavone structure shown on the left side of the figure.
Regarding Figure 4:

(A) What is the fruit or vegetable shown to the left of the carrot? Is it bell pepper or another fruit/vegetable? In general, bell peppers contain little or almost no lycopene, and presenting it in this context may mislead readers. The authors are advised to specify the names of the fruits and vegetables in the figure legend to improve readability and clarity.

(B) The lower part of Figure 4 lists four urologic malignancies (UMs), including prostate cancer (PCa), bladder urothelial cancer (BCa), renal cell carcinoma (RCC), and testicular germ cell tumors (TGCT). Does this imply that lycopene has interventional effects on all four tumor types? However, the related content in Section 3.1 does not clearly support this point. The authors should clarify the intended meaning of Figure 4 so that readers from different backgrounds can understand it correctly.

(C) The content in L318–359 does not appear to be closely related to Figure 4, yet Figure 4 is cited at L359. Please check whether this figure citation is incorrect.

For Figure 5, it is suggested that the description of ursolic acid (UA) currently presented in L457–472 be moved forward to around L406. This would make the structure and sequence of the section more logical and easier for readers to follow.
Tables 2 and 3 should be merged to reduce repetitive content, highlight the key information, and avoid confusing readers.

Author Response

REVIEWER 4:

Comments and Suggestions for Authors

The manuscript has the following issues that merit further consideration.

Overall positioning of the manuscript

Response: We thank the reviewer for this important recommendation. We agree that the previous wording could, in some places, be interpreted as assigning tumor-directed therapeutic properties to nutraceutical or health-product preparations beyond the level supported by the evidence. We have therefore reconsidered the positioning of the manuscript and revised the title, Abstract, Introduction, section headings, figure legends, table headings and footnotes, cancer-specific discussions, and Conclusion. Throughout the revised manuscript, nutraceuticals are now described as investigational exposures or as compounds with potential health-supportive, physiological, or biological effects rather than as treatments for uro-oncologic malignancies.

Figure 1 has been retitled “Core signaling hubs potentially modulated by plant-derived nutraceuticals in uro-oncology.” Its legend now clarifies that the illustrated relationships are derived predominantly from experimental evidence and do not represent validated therapeutic targeting, established clinical efficacy, or recommendations for patient use.

We have also systematically replaced potentially overstated expressions such as “therapeutic potential,” “therapeutic opportunity,” “anticancer efficacy,” and “adjunctive therapy” with evidence-qualified terminology, including “mechanistic rationale,” “reported biological activity,” “translational research potential,” and “potential supportive intervention requiring validation.” References to treatment and therapeutic efficacy have been retained only when describing established oncologic therapies, the formal design of published clinical studies, or controlled clinical outcomes.

The RCC and TGCT sections were revised particularly conservatively. RCC nutraceutical evidence is now positioned as mechanistic and pharmacologic research requiring exposure, safety, and interaction validation. In TGCT, the manuscript now emphasizes supportive-care research, reproductive safety, and non-interference with curative cisplatin-based therapy rather than exploratory tumor modulation.

Finally, we added explicit statements to the Introduction, figure legends, table footnotes, Limitations, and Conclusion that the manuscript does not support nutraceuticals as alternatives to established oncologic treatment and does not make claims that such products prevent, treat, or cure cancer.

Other issues

In Figure 1, the arrows should not overlap with other boxes, as this makes the figure appear cluttered. The authors are advised to revise the layout. In addition, the figure legend does not mention the central “Inflammation” module or the lower-left “Phenotypic outputs” module.
For the legend of Figure 2, it is recommended that the authors use more cautious wording, such as “preclinical studies suggest,” “possible mechanisms,” and “some studies have shown.” The statement regarding reduced PSA levels should be restricted to prostate cancer models. Otherwise, readers may be misled into thinking that these flavonols have already demonstrated established clinical anticancer efficacy. The legend states: “In vivo, flavonols reduce tumor size and PSA levels. In prostate cancer, they downregulate AR signaling, while in bladder cancer, they inhibit proliferation and invasion, with enhanced efficacy in combination therapy.” However, the figure itself does not clearly distinguish between in vitro and in vivo evidence. In addition, the purple and yellow boxes in the lower-right part of Figure 2 contain similar information and should be merged to make the expression more precise and easier for readers to understand.
In the upper-right part of Figure 3, it may be preferable to remove the text “EGCG” and instead insert the chemical structure of EGCG. This would correspond better to the soy isoflavone structure shown on the left side of the figure.
Regarding Figure 4:

(C) The content in L318–359 does not appear to be closely related to Figure 4, yet Figure 4 is cited at L359. Please check whether this figure citation is incorrect.

For Figure 5, it is suggested that the description of ursolic acid (UA) currently presented in L457–472 be moved forward to around L406. This would make the structure and sequence of the section more logical and easier for readers to follow.
Tables 2 and 3 should be merged to reduce repetitive content, highlight the key information, and avoid confusing readers

Response: We thank the reviewer for these detailed and helpful observations. All five figures and the two overlapping tables have been revised accordingly.

Figure 1 was redesigned using a tiered layout with non-overlapping connectors. The legend now explicitly describes the central inflammation and stress-response signaling module and the lower phenotypic-output module, including proliferation, angiogenesis, EMT/invasion/metastasis, treatment resistance, and immune evasion.

Figure 2 was revised to distinguish in vitro mechanisms from selected in vivo findings. Definitive efficacy language was replaced with cautious expressions such as “preclinical studies suggest,” “possible mechanisms,” and “some studies have shown.” PSA-related findings are now restricted explicitly to prostate cancer models. The two overlapping lower-right boxes were merged into a single module describing migration, invasion, and EMT/MMP-associated changes.

In Figure 3, the text-only EGCG element was replaced by the chemical structure of (−)-epigallocatechin-3-gallate, providing visual consistency with the soy-isoflavone structures.

Figure 4 was restricted to lycopene-related evidence in prostate cancer. Ambiguous images and foods that could be misinterpreted as major lycopene sources were removed. The revised figure identifies tomato and tomato products, watermelon, pink grapefruit, and guava by name. The PCa, BCa, RCC, and TGCT boxes were removed to avoid implying interventional effects across all four malignancies. The Figure 4 citation was removed from the unrelated general mechanistic discussion and relocated to the lycopene-related paragraph in Section 4.1, which addresses prostate cancer.

The detailed ursolic acid discussion was moved to immediately follow the curcumin paragraph and now precedes Figure 5. This revision aligns the text sequence with the two compounds presented in the figure. The Figure 5 legend was also revised to identify the evidence as preclinical and to avoid implying established chemosensitizing or clinical efficacy.

Finally, the former Tables 2 and 3 were removed, and the overlapping mechanistic and translational content of the former Tables 2 and 3 was consolidated into the current Table 3. A separate new Table 2 was added to summarize human evidence only.

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors have adequately addressed my comments and concerns.

Author Response

Reviewer 1:

The English could be improved to more clearly express the research.

Response: The manuscript has undergone comprehensive English-language editing. Long and overly complex sentences were shortened, repetitive statements were removed, terminology was standardized, and several awkward or overly promotional expressions were revised to improve clarity and scientific precision.

Reviewer 2 Report

Comments and Suggestions for Authors

No further concerns

Author Response

The English could be improved to more clearly express the research.

Reviewer 3 Report

Comments and Suggestions for Authors

Dear Authors,

Thank you for the thorough revision of the manuscript and for carefully addressing my comments. The changes introduced are satisfactory and have substantially improved the clarity, methodological transparency, and clinical relevance of the review. I have no further comments and recommend acceptance of the manuscript in its present form.

Best regards,

The reviewer.

Author Response

Response: Thank you very much for your positive evaluation and recommendation. We sincerely appreciate your valuable comments and constructive contributions, which have helped us improve the clarity, methodological transparency, and clinical relevance of the manuscript.

Reviewer 4 Report

Comments and Suggestions for Authors

The manuscript still has the following issues:

Section titles and conceptual framing
Section 2.8, “Principles for interpreting translational maturity”

The title may be more appropriately revised to “A Five-Stage Translational Maturity Framework for Nutraceutical Evidence”. In addition, the content of this section should be more explicitly linked to Table 2 so that readers can better understand the proposed framework.

Section 5, “Safety and Fundamental Clinical Pharmacology as Prerequisites for Nutraceutical Development”

The phrase “Fundamental Clinical Pharmacology” sounds somewhat awkward in the context of nutraceuticals. “Clinical pharmacology” is more commonly used in drug development and usually emphasizes pharmacokinetics, pharmacodynamics, dose–response relationships, interactions, and human exposure–response relationships. Although these aspects may also be relevant to nutraceuticals, nutritional science more commonly refers to concepts such as:

bioavailability;

absorption and metabolism;

dose–response relationship;

safety and tolerability;

nutrient–drug interactions;

clinical efficacy or health-function evidence;

quality and standardization;

target population and nutritional status.

Therefore, although the phrase is not necessarily incorrect, from a nutritional science perspective it may mislead readers into thinking that nutraceutical development should be framed in the same way as therapeutic drug development. The authors may consider revising the title to “Safety, Bioavailability, and Human Evidence in Nutraceutical Development”, or another more accurate title consistent with the content of this section. The authors are also advised to check the manuscript for other similar uses of “clinical pharmacology” and revise them where appropriate.

Table 3

In the rightmost part of the first item in Table 3, it is suggested that the authors not simply use the term “metabolites.” It would be more precise to specify “parent compound and metabolites” or “circulating and tissue-level metabolites,” because some studies may need to measure both the parent compound and its metabolites.

Newly added content and relevance to the manuscript theme

Several newly added sections do not appear to be fully aligned with the main theme of the manuscript. For example:

P8–9, L505–545

The discussion of bladder cancer mechanisms is overly long and may not be sufficiently focused on the central topic of the manuscript.

P15, L813–820

The authors state:

“The phase I/II orellanine study described by Lundstam et al. [208] provides a methodological example of this sequence: its primary objectives are safety, tolerability, and determination of the maximum tolerated dose, while pharmacokinetics and preliminary antitumor outcomes are evaluated as secondary or exploratory objectives. Orellanine is not evidence of nutraceutical efficacy and should be cited only as an example of a renal-tumor study in which dose escalation and pharmacological characterization precede efficacy interpretation.”

However, orellanine is not evidence supporting nutraceutical efficacy, and Reference 208 does not appear to be well aligned with the topic of the manuscript. The authors should carefully recheck this citation and the surrounding discussion.

[208] Ashrafpour, S.; Ashrafpour, M. The Double-Edged Sword of Nutraceuticals: Comprehensive Review of Protective Agents and Their Hidden Risks. Front Nutr 2025, 12, 1524627. doi:10.3389/fnut.2025.1524627.

More importantly, the main focus of this manuscript is not the development of novel anticancer drugs. Including an extended discussion of dose escalation, pharmacological characterization, and early-phase antitumor drug development in this section may mislead readers. The development pathway for anticancer drugs and the development pathway for nutraceuticals should not be conflated, as this may create conceptual confusion for readers.

The authors are advised to carefully review the manuscript for other similar issues, particularly where anticancer drug development is mixed with nutraceutical development, and revise the manuscript accordingly.

Author Response

Reviewer 4:

Comments and Suggestions for Authors

The manuscript still has the following issues:

Section titles and conceptual framing
Section 2.8, “Principles for interpreting translational maturity”

Response: We thank the reviewer for this helpful suggestion. The title of Section 2.8 has been revised to “A Five-Stage Translational Maturity Framework for Nutraceutical Evidence.” We also substantially revised the section to clarify the conceptual basis and operational application of the five-stage framework.

The revised text now explicitly states that the framework is applied separately to each compound–cancer–formulation context and that Table 2 operationalizes the framework by linking study design, exposure verification, biomarker findings, clinical outcomes, and safety data to the highest translational stage directly supported by each human study. We further clarified that the assigned stage should not be generalized across different formulations, doses, populations, or cancer settings.

To strengthen the connection between the section and Table 2, we added an “Assigned translational stage” column to Table 2 and included an explanatory footnote defining how the stage was determined. The concluding paragraph of Section 2.8 now summarizes the distribution of the available evidence across the five stages and explicitly notes that the human studies presented in Table 2 predominantly support pharmacologic feasibility and limited exposure-linked biomarker activity, whereas no nutraceutical has demonstrated Stage 5 clinical benefit for the treatment of a uro-oncologic malignancy.

Section 5, “Safety and Fundamental Clinical Pharmacology as Prerequisites for Nutraceutical Development”

bioavailability;

absorption and metabolism;

dose–response relationship;

safety and tolerability;

nutrient–drug interactions;

clinical efficacy or health-function evidence;

quality and standardization;

target population and nutritional status.

Response: We thank the reviewer for this important conceptual clarification. We agree that the phrase “Fundamental Clinical Pharmacology” may imply that nutraceutical development should follow the same framework as therapeutic drug development. Accordingly, the title of Section 5 has been revised to “Safety, bioavailability, and human evidence in nutraceutical development.” The section has also been substantially revised to align its terminology and conceptual framing more closely with nutritional science. The revised text now emphasizes product quality and standardization, bioavailability, absorption and metabolism, dose–response and dose–exposure relationships, safety and tolerability, nutraceutical–drug interactions, target-population characteristics, nutritional status, and the distinction between mechanistic plausibility, human biological activity, and clinical efficacy or health-function evidence. We also removed the expression “pharmacology-first approach” and replaced it with a staged framework centered on quality, safety, bioavailability, human exposure, and evidence. Similarly, the phrase “experimental pharmacological exposures” was replaced with “investigational nutritional bioactives.” Statements that could imply expected synergy between nutraceuticals and anticancer treatments were revised to clarify that mechanistic overlap may result in beneficial, neutral, interfering, or adverse effects and therefore requires direct human evaluation. In addition, the manuscript was reviewed for similar terminology. References to “clinical pharmacology” were removed where they described the overall nutraceutical development framework. The terms “pharmacokinetics” and “pharmacodynamics” were retained only where they refer specifically to formal measurements of human exposure, dose–exposure relationships, treatment interactions, or exposure-linked biological responses. In broader contexts, these terms were replaced with expressions such as “bioavailability and human exposure,” “absorption and metabolism,” “target-compartment exposure,” and “mechanism-matched biological-response biomarkers.”

Table 3

Response: We thank the reviewer for this precise and helpful recommendation. We agree that the term “metabolites” alone did not adequately describe the intended exposure assessment. Accordingly, the rightmost cell of the first item in Table 3 has been revised as follows: “Presurgical exposure study quantifying the administered parent compound(s) and relevant circulating, urinary, and tissue-level metabolites across serum, urine, and prostate tissue; primary endpoint: tissue AR activity, with p-AKT and p-S6 assessed only in tumors with baseline PI3K-pathway activation.” This revision clarifies that the proposed study should measure both the administered parent compound and its relevant metabolites in systemic, urinary, and target-tissue compartments. We also reviewed the remaining entries in Table 3 and revised similar exposure-related expressions where appropriate to distinguish parent compounds from circulating, urinary, and tissue-level metabolites. In addition, an explanatory sentence was added to the table footnote to clarify that exposure assessment should include the parent compound(s) and relevant metabolites according to the formulation and target biological compartment.

Newly added content and relevance to the manuscript theme

Several newly added sections do not appear to be fully aligned with the main theme of the manuscript. For example:

P8–9, L505–545

The discussion of bladder cancer mechanisms is overly long and may not be sufficiently focused on the central topic of the manuscript.

P15, L813–820

The authors state:

Response: We thank the reviewer for this important comment. We agree that portions of the newly added text were overly detailed and that the distinction between nutraceutical research and anticancer drug development required clearer conceptual separation. The bladder cancer section has therefore been substantially condensed. Repetitive descriptions of individual signaling pathways and extended discussions of molecular mechanisms were removed. The revised section now focuses on the aspects most relevant to the theme of the review: formulation standardization, urinary and bladder-tissue exposure, measurement of the administered parent compound and relevant metabolites, molecularly appropriate patient selection, and the use of one prespecified, mechanism-matched biological-response endpoint. We also clarified that the anatomical accessibility of the bladder facilitates exposure-focused presurgical research but does not indicate clinical readiness or therapeutic efficacy. We also removed the entire orellanine discussion from the RCC section. Orellanine is not a nutraceutical, and we agree that using its early-phase antitumor development program as a methodological model could incorrectly suggest that nutraceutical development should follow the same pathway as novel anticancer drug development. The related discussion of dose escalation, dose-limiting toxicity, maximum tolerated dose, and early antitumor activity was therefore deleted. The RCC section has been reframed around concepts more appropriate to nutraceutical research, including product quality and standardization, bioavailability, absorption and metabolism, dose–exposure relationships, safety and tolerability, renal disposition, exposure to the parent compound and relevant metabolites, and nutraceutical–drug interactions. Tumor-related biomarkers are now proposed only after acceptable exposure, safety, and treatment compatibility have been demonstrated. The citation associated with the orellanine statement was also rechecked. The attribution to Lundstam et al. and the incorrectly aligned citation were removed, and the reference list and numbering were updated accordingly. Ashrafpour and Ashrafpour is retained only where directly relevant to the safety and potential risks of nutraceutical use. Finally, we reviewed the manuscript for similar instances in which anticancer drug-development terminology was applied too broadly to nutraceutical research. Expressions such as “pharmacology-first,” “maximum tolerated dose,” “dose-limiting toxicity,” and “experimental pharmacological exposures” were removed or revised where inappropriate. The terms “pharmacokinetics” and “pharmacodynamics” were retained only when referring to specific measurements of human exposure, treatment interactions, or exposure-linked biological responses.

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Nutraceuticals in Uro-Oncology: A Structured Expert Review and Precision-Oriented Framework

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