Search Results (148)

Aging is a complex physiological process that profoundly affects the functionality of the musculoskeletal system, contributing to an increase in the incidence of diseases such as osteoporosis, osteoarthritis, and sarcopenia. Cellular senescence plays a crucial role in these degenerative processes, promoting chronic inflammation and tissue dysfunction through the senescence-associated secretory phenotype (SASP). Recently, senotherapeutics have shown promising results in improving musculoskeletal health. Natural compounds such as resveratrol, rapamycin, quercetin, curcumin, vitamin E, genistein, fisetin, and epicatechin act on key signaling pathways, offering protective effects against musculoskeletal decline. On the other hand, molecules such as dasatinib, navitoclax, UBX0101, panobinostat, and metformin have been shown to be effective in eliminating or modulating senescent cells. However, understanding the mechanisms of action, long-term safety, and bioavailability remain areas for further investigation. In this context, physical exercise emerges as an effective non-pharmacological countermeasure, capable of directly modulating cellular senescence and promoting tissue regeneration, representing an integrated strategy to combat age-related diseases. Therefore, we have provided an overview of the main anti-aging compounds and examined the potential of physical exercise as a strategy in the management of age-related musculoskeletal disorders. Further studies should focus on identifying synergistic combinations of pharmacological and non-pharmacological interventions to optimize the effectiveness of anti-aging strategies and promoting healthier musculoskeletal aging. Full article

Cellular senescence is closely connected with cancer progression, recurrence, and metastasis. Senotherapy aims to soothe the harmful effects of senescent cells either by inducing their apoptosis (senolytic) or by suppressing the senescence-associated secretory phenotype (SASP) (senomorphic). Fisetin, a well-studied senotherapeutic drug, was selected for this study to evaluate its efficiency when delivered in a liposomal formulation. The experiment evaluated the impact of liposome-encapsulated fisetin on senescent cells induced by doxorubicin (DOX) from two cell lines: WI-38 (normal lung fibroblasts) and A549 (lung carcinoma). Senescence was characterized by SA-β-galactosidase (SA-β-gal) activity, proliferation, morphology, and secretion of pro-inflammatory interleukin 6 (IL-6) and interleukin 8 (IL-8). Due to fisetin’s hydrophobic nature, it was encapsulated in liposomes to enhance cellular delivery. Cellular uptake studies confirmed that the liposomes were effectively internalized by both senescent cell types. Treatment with fisetin-loaded liposomes revealed a lack of senolytic effects but showed senomorphic activity, as evidenced by a significant reduction in IL-6 and IL-8 secretion in senescent cells. The liposomal formulation enhanced fisetin’s therapeutic efficacy, showing comparable results even at the lowest tested concentration. Full article

Flavonols, representing a subclass of flavonoids, are an important group of polyphenols. Their activity is associated with a number of beneficial properties, including hepatoprotective, senolytic, neuroprotective, and anticancer properties. They are found abundantly in many fruits, vegetables, and plant products, but flavonols’ chemistry and structural properties result in their low bioavailability in vivo. In recent years, more and more studies have emerged that aim to increase the therapeutic potential of compounds belonging to this group, including by developing innovative nanoformulations. The present work focuses on the various steps, such as chemical analysis of the compounds, preformulation studies using drug delivery systems, preclinical studies, and finally clinical trials. Each of these elements is important not only for the innovation and efficacy of the therapy but most importantly for the patient’s health. There are also a limited number of studies assessing the population concentration of flavonols in the blood; therefore, this review presents an up-to-date survey of the most recent developments, using the most important compounds from the flavonol group. Full article

DYRK1A kinase is a critical regulator in cellular signaling pathways and a promising therapeutic target for neurodegenerative diseases, diabetes and cancers. Despite its significance, the development of potent, selective and safe inhibitors remains a significant challenge. Several natural flavonoids have been reported to inhibit DYRK1A by binding in the ATP-binding pocket, exhibiting antidiabetic properties. However, a systematic screening of these structural derivatives remains lacking. In this study, we aimed to expand the pool of flavonoid-based DYRK1A inhibitor candidates for drug development against DYRK1A through targeted screening and structure-based analysis. A focused library of 13 flavonoid derivatives was screened to identify novel DYRK1A inhibitors, revealing eight new flavonol inhibitors with IC₅₀ values ranging from 149.5 nM to 737.9 nM. Among these, fisetin demonstrated the highest potency with an IC₅₀ of 149.5 nM, followed by kaempferol (296.3 nM), isorhamnetin (418 nM), morin (478.4 nM), myricetin (633.2 nM) and luteolin (797.8 nM), all exhibiting submicromolar inhibitory activity. Additional novel inhibitors, Apigenin and Kaempferide, also showed effective inhibition. As controls, the previously known inhibitors quercetin and curcumin were evaluated, yielding IC₅₀ values of 737.9 nM and 2.35 μM, respectively, which validated the assay conditions. To the best of our knowledge, fisetin is the most potent known DYRK1A inhibitor among flavonoids. Cellular assays further demonstrated that the top flavonoid hits induced dose-dependent cytotoxicity and morphological changes in HeLa cells. Structure-activity relationship and molecular simulation analysis revealed that the selected flavonols interact with key residues for DYRK1A inhibition. These results highlight flavonols as a promising scaffold for DYRK1A inhibition and provide valuable natural inhibitor leads for further optimization and therapeutic development. Full article

Cellular senescence leads to stable cell cycle arrest and an inflammatory senescence-associated secretory phenotype that varies with stressor and cell type. To mitigate these effects and improve health, senotherapeutics (e.g., senolytics and senomorphics) have been developed. Senescent-like endometrial stromal cells (eSCs) lining the uterus of patients with endometriosis and infertility are proposed to impair decidualization, a differentiation process required for uterine receptivity in humans. Quercetin, a natural flavonoid senolytic, dramatically improves decidualization and reduces endometriosis in rodent models. However, little is known about the comparative effects of various senotherapeutics on eSCs. Using menstrual effluent-derived eSCs, we evaluated the effects of flavonoid and non-flavonoid compounds on eSC functions associated with endometriosis, aiming to identify optimal senotherapeutics for future clinical trials. Among flavonoids tested, all senolytics (quercetin, fisetin, and luteolin) and kaempferol, a senomorphic, significantly improved decidualization without cytotoxicity. Although non-flavonoids exhibited notable cytotoxicity, dasatinib, but neither ABT-737 nor navitoclax, enhanced decidualization. Flavonoid senotherapeutics and dasatinib significantly inhibited eSC migration. Mechanistic studies revealed that all flavonoids and dasatinib suppressed AKT phosphorylation and upregulated p53 expression. Notably, only quercetin and fisetin reduced ERK1/2 phosphorylation. Furthermore, flavonoid-senolytics and dasatinib consistently eliminated senescent eSCs. These findings support future studies to assess the therapeutic potential of in vivo supplementation with flavonoid senolytics on eSC function using menstrual effluent. Full article

Parkinson’s disease (PD) is an aging-related neurodegenerative disease characterized by a progressive loss of dopamine (DA)-secreting neurons in the substantia nigra. Most of the currently available treatments attempt to alleviate the disease symptoms by increasing DA transmission in the brain and are associated with unpleasant side effects. Since there are no treatments that modify the course of PD or regenerate DA neurons, identifying therapeutic strategies that slow, stop, or reverse cell death in PD is of critical importance. Here, factors that confer vulnerability of substantia nigra DA neurons to cell death and the primary mechanisms of PD pathogenesis, including cellular senescence, a cellular stress response that elicits a stable cell cycle arrest in mitotic cells and profound phenotypic changes including the implementation of a pro-inflammatory secretome, are reviewed. Additionally, a discussion of the characteristics, mechanisms, and markers of cellular senescence and the development of approaches to target senescent cells, referred to as senotherapeutics, is included. Although the senotherapeutics curcumin, fisetin, GSK-650394, and astragaloside IV had disease-modifying effects in in vitro and in vivo models of PD, the potential long-term side effects of these compounds remain unclear. It remains to be elucidated whether their beneficial effects will translate to non-human primate models and/or human PD patients. The enhanced selectivity, safety, and/or efficacy of next generation senotherapeutic strategies including senolytic peptides, senoreverters, proteolysis-targeting chimeras, pro-drugs, immunotherapy, and nanoparticles will also be reviewed. Although these next generation senotherapeutics may have advantages, none have been tried in models of PD. Full article

The genus Terminalia has a long history of use in traditional medicine to treat various diseases, including bacterial infections. We previously reported a metabolomic analysis using liquid chromatography–mass spectrometry of selected Australian Terminalia spp. and highlighted numerous flavonoids that may contribute to the antimicrobial activities of those plants. This study examines the antibacterial activities of fifteen flavonoids found in Terminalia spp. against a range of gastrointestinal pathogens using broth dilution assays. Flavonoids were also combined with six different classes of conventional antibiotics to investigate interactions. The efflux pump inhibitory activity of the flavonoid was evaluated using ethidium bromide accumulation and efflux assays. Toxicities were assessed via human dermal fibroblast cell line assays. Fisetin, hispidulin, isoorientin, orientin, rutin, and vitexin showed noteworthy growth inhibitory activity (MIC values 62.5–250 µg/mL). Isoorientin and orientin were most potent against Bacillus cereus and Alcaligenes faecalis, displaying MIC values of 62.5 µg/mL against both bacteria. All flavonoids except genistein, isorhamnetin, kaempferol, luteolin, taxifolin, and vitexin were nontoxic in human dermal fibroblast (HDF) cell proliferation assays. When individual flavonoids were combined with selected antibiotics, some potentiated the activity of these antibiotics. Two synergistic, eighteen additive and thirty-one non-interactive interactions were observed. The synergistic interactions were all observed in combination with orientin. Notably, orientin exhibited efflux pump inhibitory effects at concentrations from 15.26 µg/mL to 125 µg/mL. The findings reported herein indicate that the selected flavonoids have the potential for addressing bacterial antibiotic resistance and highlight the need for further study. Full article

Zinc (Zn) imbalance—deficiency or overload—is implicated in hepatocyte injury, yet its mechanisms and therapeutic strategies remain incompletely understood. This study investigated Zn dyshomeostasis-induced hepatotoxicity in AML12 hepatocytes and evaluated fisetin’s protective potential in diet-induced Zn overload C57BL/6 mice for in vivo validation. In AML12 cells, both Zn deficiency and overload impaired hepatocyte viability and promoted oxidative stress, but only overload activated autophagy and the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway. Fisetin, a natural flavonoid with well-documented antioxidant and anti-inflammatory properties, selectively mitigated Zn overload-induced AML12 cytotoxicity and oxidative damage by enhancing autophagic flux and Nrf2 signaling without Zn chelation, while demonstrating no effect on Zn deficiency. Specifically, fisetin required autophagy to sustain Nrf2 activation, as chloroquine abolished its protective effects. In vivo, fisetin administration (200 mg/kg BW, oral gavage) alleviated Zn overload-associated weight loss and hepatic oxidative damage in mice, paralleling its in vitro effects through reinforced autophagy–Nrf2 axis activation. The autophagy-dependent Nrf2 activation mechanism highlights fisetin’s therapeutic potential for Zn-related liver disorders. Full article

Background: Polycyclic aromatic hydrocarbons such as Benzo(a)Pyrene, which are produced by smoking or present in air pollution, greatly contribute to lung diseases. B(a)P has been found to induce inflammation and eventually lung cancer. Fisetin, a polyphenol, abundant in many fruits and vegetables, has an appealing therapeutic potential in many disorders, including inflammation and cancer. Objectives: This study aimed to investigate the importance of fisetin in the regulation of chronic lung inflammation and oxidative stress resulting from exposure to Benzo(a)Pyrene. Methods: The effect of fisetin on rats at a concentration of 50 mg/kg was evaluated by ELISA to measure oxidative stress and inflammatory markers. The tissue architecture was also investigated using hematoxylin and eosin (H&E) staining. The expression pattern of IL-6 in lung tissues was assayed using immunohistochemistry. Fibrosis was evaluated in lung tissues using Masson Trischrome and Sirius red stains. Cell apoptosis in lung tissues was studied using a TUNEL assay. Results: After exposure to Benzo(a)Pyrene for eight weeks, the data indicated that fisetin led to a significant reduction in oxidative stress, evidenced by the reduction of SOD, MDA, NO, GPH, and GPx. Moreover, IL-6, TNF-α, and CRP levels were also decreased, indicating a reduction in inflammation. Apoptosis was reduced upon fisetin treatment. Furthermore, a significant decrease in fibrosis was also observed. Conclusions: This study reveals the importance of fisetin as a natural product in the management of chronic lung injury by protecting lung tissues from inflammation, and its use suggests better prognosis in diseases caused by exposure to B(a)P. Full article

In this study, the antioxidant activity of 25 natural tea flavonoids was evaluated using Density Functional Theory (DFT), which identified four flavonoids with strong antioxidant activity: kaempferol, fisetin, quercetin, and myricetin. The analysis of electronic structures confirmed the positive effects of the number of -OH groups and intramolecular hydrogen bonds on the reactivity toward radicals. Electronic properties and potential energy curves (PECs) confirmed this view. Additionally, the solvation effect analysis indicated that a polar environment enhanced the antioxidant capacity of the products. Flavonoids exhibiting a Hydrogen Atom Transfer (HAT) mechanism, as the preferred antioxidant mechanism, show great potential for applications in fields such as biology, medicine, and food. Full article

Although interferon-gamma (IFN-γ) is known as a critical factor in polarizing macrophages into the pro-inflammatory state for immune response, how dietary flavonoids regulate IFN-γ response for anti-inflammation is incompletely elucidated. This study aims to investigate the effect of fisetin, a typical flavonol, on the inhibition of IFN-γ-induced inflammation by RNA sequencing (RNA-Seq) and cellular metabolism analysis. RAW264 macrophages pretreated with fisetin following IFN-γ stimulation were subjected to RNA-Seq to analyze alterations in gene expression. Cellular signaling and transcription were investigated using enrichment analysis, motif analysis, and transcription factor prediction. Cellular metabolic state was assessed by measuring the oxygen consumption rate (OCR) and lactate level to reflect mitochondrial respiration and glycolysis. Alterations in signaling proteins were confirmed by Western blot. The results revealed that fisetin downregulated the IFN-γ-induced expression of pro-inflammatory genes and M1 marker genes such as Cxcl9, Il6, Cd80, Cd86, and Nos2. In cellular metabolism, fisetin upregulated the oxidative phosphorylation (OXPHOS) pathway, restored impaired OCR, and reduced lactate production induced by IFN-γ. Motif analysis suggested that fisetin suppressed the activation of IFN-regulatory factor 1 (IRF1). Western blot data further confirmed that fisetin inhibited the phosphorylation of Jak1, Jak2, and STAT1, and decreased the nuclear accumulation of phosphorylated STAT1 and IRF1 induced by IFN-γ. Taken together, our data revealed that fisetin is a potent flavonoid that attenuates IFN-γ-stimulated murine macrophage inflammation and ameliorates disrupted cellular metabolism with a possible Jak1/2-STAT1-IRF1 pathway. Full article

Background: Cellular senescence is a biological process with a dual role in organismal health. While transient senescence supports tissue repair and acts as a tumor-suppressive mechanism, the chronic accumulation of senescent cells contributes to aging and the progression of age-related diseases. Senotherapeutics, including senolytics, which selectively eliminate senescent cells, and senomorphics, which modulate the senescence-associated secretory phenotype (SASP), have emerged as promising strategies for managing age-related pathologies. Among these, polyphenols, a diverse group of plant-derived bioactive compounds, have gained attention for their potential to modulate cellular senescence. Methods: This review synthesizes evidence from in vitro, in vivo, and clinical studies on the senolytic and senomorphic activities of bioactive polyphenols, including resveratrol, kaempferol, apigenin, and fisetin. The analysis focuses on their molecular mechanisms of action and their impact on fundamental aging-related pathways. Results: Polyphenols exhibit therapeutic versatility by activating SIRT1, inhibiting NF-κB, and modulating autophagy. These compounds demonstrate a dual role, promoting the survival of healthy cells while inducing apoptosis in senescent cells. Preclinical evidence indicates their capacity to reduce SASP-associated inflammation, restore tissue homeostasis, and attenuate cellular senescence in various models of aging. Conclusions: Polyphenols represent a promising class of senotherapeutics for mitigating age-related diseases and promoting healthy lifespan extension. Further research should focus on clinical validation and the long-term effects of these compounds, paving the way for their development as therapeutic agents in geriatric medicine. Full article

Liver cancer is one of the most prevalent cancers worldwide. The first-line therapeutic drug sorafenib offers only a moderate improvement in patients’ conditions. Therefore, an approach to enhancing its therapeutic efficacy is urgently needed. It has been revealed that hepatocellular carcinoma (HCC) cells with heightened intracellular quiescin sulfhydryl oxidase 1 (QSOX1) exhibit increased sensitivity to sorafenib. QSOX1 is a secreted disulfide catalyst, and it is widely recognized that extracellular QSOX1 promotes the growth, invasion, and metastasis of cancer cells through its participation in the establishment of extracellular matrix. Inhibiting QSOX1 secretion can increase intracellular QSOX1 and decrease extracellular QSOX1. Such an approach would sensitize HCC cells to sorafenib but remains to be established. Since (−)-epigallocatechin-3-gallate (EGCG) has been demonstrated to be an effective inhibitor of α-fetal protein secretion from HCC cells, we screened QSOX1 secretion inhibition using polyphenolic compounds. We examined eight dietary polyphenols (EGCG, quercetin, fisetin, myricetin, caffeic acid, chlorogenic acid, resveratrol, and theaflavin) and found that EGCG and quercetin effectively inhibited QSOX1 secretion from human HCC cells (HepG2 or Huh7), resulting in high intracellular QSOX1 and low extracellular QSOX1. The combination of EGCG or quercetin, both of which change the cellular distribution of QSOX1, with sorafenib, which has no influence on the cellular distribution of QSOX1, exhibited multiple synergistic effects against the HCC cells, including the induction of apoptosis and inhibition of invasion and metastasis. In conclusion, our current results suggest that dietary EGCG and quercetin have the potential to be developed as adjuvants to sorafenib in the treatment of HCC by modulating the cellular distribution of QSOX1. Full article

Previously we discovered that among 15 DNA-binding plant secondary metabolites (PSMs) possessing anticancer activity, 11 compounds cause depletion of the chromatin-bound linker histones H1.2 and/or H1.4. Chromatin remodeling or multiH1 knocking-down is known to promote the upregulation of repetitive elements, ultimately triggering an interferon (IFN) response. Herein, using HeLa cells and applying fluorescent reporter assay with flow cytometry, immunofluorescence staining and quantitative RT-PCR, we studied effects of PSMs both evicting linker histones from chromatin and not influencing their location in nucleus. We found that (1) 8 PSMs, evicting linker histone H1.2 from chromatin, activated significantly the type I IFN signaling pathway and out of these compounds resveratrol, berberine, genistein, delphinidin, naringenin and curcumin also caused LINE1 expression. Fisetin and quercetin, which also induced linker histone H1.2 eviction from chromatin, significantly activated only type I IFN signaling, but not LINE1 expression; (2) curcumin, sanguinarine and kaempferol, causing significant depletion of the chromatin-bound linker histone H1.4 but not significantly influencing H1.2 presence in chromatin, activate type I IFN signaling less intensively without any changes in LINE1 expression; (3) four PSMs, which did not cause linker histone eviction, displayed neither IFN signaling activation nor enhancement of LINE1 expression. Thus, we have shown for the first time that chromatin destabilization observed by depletion of chromatin-bound linker histone H1.2 caused by anticancer DNA-binding PSMs is accompanied by enhancement of type I IFN signaling, and that LINE1 expression often impacts this activation. Full article

Background/Objective: In recent studies, it has been shown that dietary bioactive compounds can produce health benefits; however, it is not known whether an improvement in solubility can enhance their biological effects. Thus, the aim of this work was to study whether co-amorphous (CoA) naringenin or fisetin with enhanced solubility modify glucose and lipid metabolism, thermogenic capacity and gut microbiota in mice fed a high-fat, high-sucrose (HFSD) diet. Methods: Mice were fed with an HFSD with or without CoA-naringenin or CoA-fisetin for 3 months. Body weight, food intake, body composition, glucose tolerance, hepatic lipid composition and gut microbiota were assessed. Results: CoA-naringenin demonstrated significant reductions in fat-mass gain, improved cholesterol metabolism, and enhanced glucose tolerance. Mice treated with CoA-naringenin gained 45% less fat mass and exhibited improved hepatic lipid profiles, with significant reductions seen in liver triglycerides and cholesterol. Additionally, both CoA-flavonoids increased oxygen consumption (VO₂), contributing to enhanced energy expenditure and improved metabolic flexibility. Thermogenic activation, indicated by increased UCP1 and PGC-1α levels, was observed with CoA-fisetin, supporting its role in fat oxidation and adipocyte size reduction. Further, both CoA-flavonoids modulated gut microbiota, restoring diversity and promoting beneficial bacteria, such as Akkermansia muciniphila, which has been linked to improved metabolic health. Conclusions: These findings suggest that co-amorphous naringenin or fisetin offers promising applications in improving solubility, metabolic health, and thermogenesis, highlighting the potential of both as therapeutic agents against obesity and related disorders. Full article