Metabolic Modulation of Type 2 Diabetes Mellitus by 1-Deoxynojirimycin: A Multifaceted Approach
Round 1
Reviewer 1 Report
This review makes a relevant and valuable contribution to the discussion on DNJ and T2DM for several reasons:
Rather than merely reiterating that DNJ acts as an α-glucosidase inhibitor, the review systematically integrates its effects on multiple aspects of glucose metabolism, including glycolysis, the TCA cycle, the pentose phosphate pathway, gluconeogenesis, and glycogen metabolism, as well as on lipid metabolism, insulin resistance, inflammation, and gut microbiota. This provides a comprehensive and multifaceted perspective that is rarely consolidated within a single study.
The review compiles and systematizes findings from in vivo studies and selected clinical trials (Table 1), including detailed information on dosage, purity, duration, route of administration, and observed outcomes. This structured approach facilitates a more critical assessment of the quality, consistency, and translational relevance of the available evidence on DNJ in T2DM.
Beyond describing phenotypic effects, the review delves into specific molecular mechanisms, including key signaling pathways. It also addresses alterations in enzyme activity and gene expression, along with the role of gut microbiota and their metabolites, thereby offering a level of mechanistic insight that can inform and guide future experimental research.
Some improvements are suggested, but it is worth noting that the manuscript is well-written, as indicated below:
Clarify the scope at the end of the Introduction. Add one or two very explicit sentences, such as “This review will focus on…,” listing the main areas: glucose, lipids, insulin resistance, gut microbiota, and network pharmacology. This helps the reader understand the overall structure of the manuscript from the outset.
Include transition sentences between the main sections (e.g., from glucose metabolism to lipid metabolism, and from there to the microbiota) that explain in one or two lines how these levels relate to each other and to type 2 diabetes.
Ensure that all figure abbreviations (UCP1, PRDM16, etc.) are defined in the legend or refer to the list of abbreviations.
Author Response
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Author Response File: 
Author Response.docx
Reviewer 2 Report
Diabetes is a serious disease that is being diagnosed with increasing frequency in the population. Thus, the search for substances, including natural ones, that may be helpful in its treatment aligns with current trends.
Comment 1: The presented article concerns 1-deoxynojirimycin, a compound with known antidiabetic activity. Although the article is interesting, it is unclear why the authors do not refer to other review papers on this topic that have been published within the past year (listed below: Mehmood et al., 2025; Tricase et al., 2025, Roghan et al., 2025). The authors should clarify how their manuscript compares with these recent literature reviews. They should also more strongly emphasize what is novel in their work and clearly state the aim of the article.
Mehmood A, Battino M, Chen X. 1-Deoxynojirimycin: a comprehensive review of sources, biosynthesis pathways, strategies to enhance its production, and anti-diabetic activities. Food Funct. 2025 Jun 16;16(12):4673-4701. doi: 10.1039/d4fo04954c. PMID: 40476467.
Tricase AF, Cavalluzzi MM, Catalano A, De Bellis M, De Palma A, Basile G, Sinicropi MS, Lentini G. Insights into the Activities and Usefulness of Deoxynojirimycin and Morus alba: A Comprehensive Review. Molecules. 2025; 30(15):3213. https://doi.org/10.3390/molecules30153213
Roghan HB, Sekar I, Sivaprakash M S. Critical Review of 1-Deoxynojirimycin (DNJ) in Mulberry in Curing Diabetes Mellitus. Pharmacognosy Magazine. 2025;0(0). doi:10.1177/09731296251383290
Other comments are presented in section "detailed comments"
Comment 1: The article lacks a description of the methodology used for the literature search. The Authors should specify the scope of the review, the databases used, the time range of the publications considered, as well as the inclusion and exclusion criteria, and other relevant methodological details.
Comment 2: The Authors use the term “mulberry.” They should (at least once) provide the Latin species name of the plant from which the compound and the DNJ-rich extract are obtained.
Comment 3: Page 2: The Authors state, “DNJ has historically been utilised in traditional Chinese medicine for management of diabetes.” No reference is provided to support this claim. Is DNJ really meant here—as an isolated compound? Historically, for how long has it been isolated in pure form? Perhaps the authors are actually referring to mulberry extracts. The text should be revised accordingly and supported with an appropriate literature reference.
Comment 4: Table 1: The authors state in the title: “Research on DNJ in vivo models and clinical trials…” This is an oversimplification that may mislead the reader. Only the in vivo studies are conducted on the pure compound. Clinical studies, however, are performed on mulberry extracts (from specific parts of the plant, which should be clearly indicated), not on the pure substance. This means that it is unclear what exactly is responsible for the observed effects and whether other components in the extract may interact (e.g., synergistically). Therefore, the effect cannot be attributed solely to DNJ. For this reason, studies on extracts (both in vitro and clinical - only selected ones are presented by the authors) should be clearly separated from those conducted on the pure compound, which is the main subject of this review article.
Comment 5: In Table 1 (page 7), a study is presented in which DNJ and “mulberry pigment” were investigated. The term “pigment” is imprecise and should be clarified by specifying the exact compound being referred to.
Comment 6: At the first use of the abbreviation "DNJ" in the Introduction, the full name of the compound should be provided. There should also be a reference to the figure presenting the chemical structure of the substance.
Comment 7: Page 19 – Last paragraph before the conclusion: “Although network pharmacology has identified key pathways for DNJ in T2DM (e.g., PI3K-AKT and AMPK), current analysis often focus on isolated compounds or extracts. Future network pharmacology studies should integrate data on food processing methods, nutritional contexts, and dietary structures to better predict DNJ's efficacy andsafety as a functional food component. Furthermore, differences in safety requirements and the severity of symptoms targeted by food and TCM may lead to variations in targets and associated signalling pathways. Therefore, further in-depth research on functional foods is required to ensure the scientific validity and practical applicability of these findings.”
It's completely incomprehensible. It's unclear what the authors mean. Network pharmacology must have a specific target and a potentially active substance with a defined chemical structure that can be "theoretically tested." Therefore, it's unclear what the dietary structures, food processing methods, and nutritional contexts are all about. The statement: "Differences in safety requirements and the severity of symptoms targeted by food and TCM may lead to variations in targets" is also unclear. This paragraph should be rewritten.
Author Response
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Author Response File: Author Response.docx
Reviewer 3 Report
Dr. Qinghai Sheng and colleagues have compiled a review on the topic of "Metabolic modulation of type 2 diabetes mellitus by 1-Deoxynojirimycin: A multifaceted approach".
This manuscript is timely, contains 68% references to current literature, and addresses the pressing issue of the increasing incidence of type 2 diabetes and its prevention through natural medicine methods.
The authors discussed the importance of 1-deoxynojirimycin (DNJ) as a promising natural compound, offering a multifaceted approach to combating this complex metabolic disorder.
The authors demonstrated the need for further research and validation to confirm the efficacy of DNJ in the prevention and treatment of type 2 diabetes, particularly in its early stages.
This manuscript should be published in the journal Antioxidants after correcting the minor editorial deficiencies listed at detailed comments.
At page 1 at line 4 on Introduction is … 2050[1,2] … , but it should be with a space before the bracket … 2050 [1,2] … . Similar errors to be corrected can be found on pages;
page 2 … dysfunction[3,4] … , … mori)[8,9] … , … sugar[10-13] … ;
page 8 … intestine[41,42] … ;
page 9 … glucose[43] … , … inhibitors[44,45] … , … activity[17] … , … absorption[12] … ;
page 10 … neurons[49] … , … incidence[50,51] … , … resistance[52] … , … function[53] … , … findings[54] … ;
page 11 … levels[55] … , … glucose[51] … , … (FOXO1)[56,57] … , … mice[19] … , … glucosidase[17] … ;
page 12 … balance[58,59] … , … homeostasis[60,61] … , … muscle[62] … ;
page 13 … fasting[63,64] … , … deposition[61] … , … activity[65] … , … dysfunction[66] … , … metabolism[26] … , … levels[67] … , … muscle[12] … ;
page 14 … dyslipidemia[69] … , … patients[70] … , … muscles[61] … , … pathways[71] … , … IR[72] … , … liver[73] … , … dysfunction[74] … , … WAT[75] … ;
page 15 … hyperglycemia[76,77] … , … ROS[78] … , … (MAPK)[79] … , … resistance[80] … , … components[15,47,81] … , … IR[82] … ;
Page 16 … IR[83] … , … levels[84] … , … capacity[85] … , … homeostasis[12] … , … IR[12,86] … , … mechanisms[87,88] … , … regulation[89,90] … , … endotoxemia[92] … , … increases[93] … , … IR[94,95] … , … nflammation[70,96-98] … ;
page 17 … dyslipidemia[99,100] … , … sensitivity[102] … , … T2DM[12,103] … , … complications[20,84] … ;
page 18 … action[104-106] … , … diseases[104,106] … ... diabetes[10,107,108] ... , ... formation[81] ... , ... al.[10] ...;
and page 19 ... complications[109,110] ... .
At page 18 is ... maltase-glucoamylase, sucrase-isomaltase proteins, ... , but the sentence should begin with a capital letter … Maltase-glucoamylase, sucrase-isomaltase proteins, … .
Page 19, paragraph 7. Conclusions should be a bit more elaborated considering the authors' extensive discussion.
Author Response
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Author Response File: Author Response.docx
Reviewer 4 Report
The manuscript aims to provide an overview of the role of DNJ—a natural alkaloid found in plants, microbes, and insects, or produced via chemical synthesis—in the management of T2DM. This compound’s potent inhibitory effect on α-glucosidase is well-supported by the cited in vitro and in vivo data. The manuscript is divided into sections describing glucose and lipid metabolism, insulin resistance, and the role of microbiota in T2DM, with a final section on network pharmacology as a modern approach to studying the multi-target potential of natural compounds. Each section incorporates the potential role of DNJ in alleviating the complex metabolic dysfunctions associated with T2DM.
However, despite the authors' claim that this review is comprehensive, they provide no methodology regarding the literature search, nor any inclusion or exclusion criteria for the data presented. Consequently, the review lacks critical, analytical, or interpretive synthesis; it fails to identify flaws, biases, or contradictions within the existing studies, offering little more than a descriptive summary of existing literature.
Many phrases are not clear, and in many cases the references are missing:
Examples:
Page 14 “This results in the promotion of fat breakdown and energy expenditure. Further studies on the effects of DNJ on BAT and the browning of WAT are crucial. Further investigating the impact of DNJ on thermogenic capacity, mitochondrial dynamics, fatty acid oxidation, glucose oxidation, and insulin sensitivity will not only supplement the current understanding of adipose tissue metabolic plasticity but also provide potential therapeutic strategies for T2DM and related metabolic diseases”
Page18: “Through network pharmacology analysis, Lv et al. [108] revealed that the active components in mulberry leaves are the PI3K-AKT signalling pathway and lipid peroxidation. maltase-glucoamylase, sucrase-isomaltase proteins, and α-galactosidase are the core targets of mulberry alkaloids, which improve IR by regulating glucose metabolism. DNJ, a principal active component of mulberry leaf alkaloids, regulates carbohydrate metabolism and possesses anti-T2DM properties.”
Page 18: “Network pharmacology analysis revealed that mulberry leaf extract modulates lipid and glucose metabolism through the lipid metabolism, atherosclerosis, PI3K–AKT, and AGE–RAGE signalling pathways, and exerts anti-inflammatory effects by targeting cytokines such as IL-6, IL-10, and TNF” references are missing!!!
While the manuscript touches upon an important topic, it currently lacks the novelty and academic rigor required for publication. Specifically, several critical aspects are entirely omitted: DNJ’s bioavailability, its long-term safety profile, and its pharmacokinetics. These factors are essential for evaluating the compound's potential development as either a functional food or a therapeutic agent
To be a viable contribution to the field, the manuscript would require a complete conceptual and structural overhaul.
See above or the detailed comments.
Author Response
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Author Response File: Author Response.docx
Round 2
Reviewer 2 Report
I thank the Authors for their clarifications. I believe the manuscript has improved significantly; many issues are now clearer and more coherently explained. In my opinion, it can be published in its current form.
no comments
Reviewer 4 Report
The authors did not answer all my questions. Table 1 is still in the introduction, table 2 is without references and it presents data that are well known, about the role of enzymes involved in glucose metabolic pathways.
The revised manuscript is far from a publishable form in a journal like Antioxidants.
my comments are presented above
