Dietary kaempferol exerts anti-obesity effects by inducing the browing of white adipocytes via the AMPK/SIRT1/PGC-1α signaling pathway

Clostridium butyricum ameliorates post-gastrectomy insulin resistance by regulating the mTORC1 signaling pathway through the gut-liver axis

Postoperative insulin resistance (IR) is a metabolic disorder characterized by decreased insulin sensitivity and elevated blood glucose levels following major surgery. Our previous clinical study identified a notable correlation between postoperative IR and gut microbiota, particularly butyrate-producing bacteria, yet the mechanisms remain unclear. In this study, we established gastric resection SD rat models to evaluate the impact of Clostridium butyricum NCU-27 (butyrate-producing bacteria) on postoperative IR. The results demonstrated significant reductions in fasting blood glucose (FBG), fasting insulin (FIns) levels, and HOMA-IR (6.64 ± 0.76 vs. 11.47 ± 1.32; 4.27 ± 0.59 vs. 7.40 ± 0.54) in the postoperative period compared to the control group (P < 0.05). Additionally, glucose tolerance and hepatic glycogen content were markedly improved (P < 0.001). Further exploration of butyrate demonstrated effects similar to C. butyricum NCU-27, potentially mediated through the gut-liver axis by inhibiting mTORC1 expression in liver cells, activating the IRS1/AKT pathway, enhancing glucose uptake and glycogen synthesis, suppressing gluconeogenesis, increasing insulin sensitivity, and improving IR. Finally, the use of mTORC1 agonists and inhibitors further confirmed the critical role of the mTORC1 pathway in mediating the beneficial effects of C. butyricum NCU-27 and butyrate on postoperative IR. In conclusion, this study elucidated that C. butyricum NCU-27 improves postoperative IR by regulating butyrate metabolism and inhibiting the mTORC1 pathway, offering new insights for preventing and treating post-gastrectomy IR.

Gallic acid prevents obesity in mice on a high-fat diet via the gut microbiota-adipose tissue axis

Obesity is closely related to the gut microbiota, and gallic acid (GA) has anti-obesity properties, but its relationship with the gut microbiota is unclear. The aim of this study was to investigate the role of gut microbiota in the anti-obesity mechanism of GA by fecal microbiota transplantation (FMT). Here, we found that high-fat diet (HFD) promoted lipid deposition and gut microbiota dysbiosis in mice, whereas GA slowed down lipid deposition and restored gut microbiota dysbiosis and its functional profile, as evidenced by the reduction of the obesity-causing bacterium Desulfovibrio and the enrichment of the beneficial bacterium Lachnospiraceae_NK4A136_group, Clostridiales_unclassified, Oscillospira and Adlercreutzia. These gut microbiota and metabolites produced positive feedback effects on body weight, glucose tolerance, insulin resistance, as well as glycemic and lipid parameters. Mechanistically, GA significantly enhanced lipid and energy metabolism in obese mice by promoting the expression of uncoupling protein 1 (UCP1), adiponectin, and adiponectin receptor 2 in white adipose tissue of the epididymal white adipose tissue, as well as promoting thermogenesis in interscapular brown adipose tissue by stimulating UCP1 expression. Interestingly, GA failed to alleviate lipid accumulation in HFD of antibiotic-treated mice. In contrast, after FMT treatment, the fecal microbiota of GA-treated donor mice significantly alleviated lipid metabolism in HFD-fed mice, which is mechanistically consistent with direct addition of GA. Collectively, GA can alleviate HFD-induced obesity by modulating the gut microbiota, and the specific mechanism may be through the gut microbiota-adipose tissue axis.

Multitargeted Effects of Plantago ovata Ethanol Extract in Experimental Rat Streptozotocin-Induced Diabetes Mellitus and Letrozole-Induced Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS), a common and multifactorial endocrine disorder in reproductive-aged women, is strongly associated with insulin resistance (IR) and type 2 diabetes mellitus (T2DM), and also affects up to one in four women with type 1 diabetes mellitus (T1DM). The current study explored the potential of Plantago ovata (P. ovata) seed ethanol extract (POEE) to modulate oxidative stress (OS), inflammatory responses, metabolic profiles, and hormonal levels in rat Streptozotocin (STZ)-induced DM and Letrozole (LET)-induced PCOS. Phytochemical analysis measured total phenolic content (TPC) and total flavonoid content (TFC) using HPLC-DAD-ESI MS for compound identification. POEE's antioxidant activity was evaluated in vitro through DPPH, H2O2, FRAP, and NO scavenging assays. Rats received POEE, metformin, or Trolox (TX) for 10 days. PCOS confirmation was achieved via ultrasound and histopathology. Serum levels of OS markers (TOS, TAC, OSI, MDA, AOPP, 8-OHdG, NO, 3-NT, AGEs, and SH), inflammatory markers (NF-κB, IL-1β, IL-18, Gasdermin D, and IL-10), metabolic parameters (fasting blood glucose, lipid profile, and liver enzymes), and hormone levels (LH, FSH, estrogen, testosterone, and insulin) were assessed. Additionally, the Triglyceride-Glucose index (TyG) and HOMA-IR were calculated. POEE had a medium content of polyphenols and a good in vitro antioxidant effect. In vivo, POEE administration in diabetic rats led to a reduction in OS markers and an increase in antioxidant levels, alongside decreases in inflammatory cytokines, blood glucose levels, and transaminase activity and improvements in lipid profile. In the PCOS model, POEE treatment effectively reduced total OS and lowered levels of LH, FSH, and testosterone, while elevating estrogen concentrations and reducing insulin resistance. These therapeutic effects were dose-dependent, with higher doses producing more pronounced outcomes, comparable to those observed with metformin and TX treatment.

Role of trans-resveratrol in ameliorating biochemical and molecular alterations in obese rats induced by a high fructose/fat diet

We evaluated the effect of trans-resveratrol (RSV) in ameliorating biochemical and molecular alterations in obese Wister male rats fed on high-fat/high-fructose-fed. Male Wister rats were divided into eight groups and fed with either a standard diet (control), high fructose (HF), high fat (HFAT), or a high- fructose high- fat (HF/HFAT) diet and supplemented with RSV (30 mg/kg/day) for 4 weeks. The food intake, body weight, glycemic parameters, lipid profile, oxidative stress were assessed. SIRT1 gene expression, PGC-1α, cyto-c and GLUT-4 were evaluated by qRT-PCR in adipose tissue of normal and obese rats. The body weight gain, serum fasting glucose, insulin, and HOMA-IR values were significantly higher in the HF and HF/HFAT groups than in the HFAT and control groups. Hyperlipidemia was observed in high calorie diets fed rats compared to control group. The levels of total cholesterol, triglycerides and LDL-c were significantly elevated while HDL- c was significantly decreased in HF & HF/HFAT groups compared to HFAT group. The levels of serum malondialdhyde (MDA) and superoxide dismutase (SOD) activity in adipose tissue were elevated in all groups compared to control group, particularly in the groups that were kept on a high fructose diets (HF, HF/HFAT). SIRT-1, PGC-1α, Cyto-c, and GLUT-4 genes levels were significantly down regulated in HF, HFAT & HF/HFAT groups compared to control group. Supplementation of T-RSV restored the alteration in carbohydrates-lipid metabolism as well as oxidative stress and upregulation of SIRT-1, PGC-1α, Cyto-c, and GLUT-4 genes. RSV is a promising treatment in the management of pathologic consequences of obesity from high-calorie diet consumption via molecular alteration of target genes.

Vitisin A Outperforms Cyanidin-3-O-Glucoside in Triglyceride Reduction by Modulating Hepatic Lipogenesis and Fatty Acid β-Oxidation

Pyranoanthocyanins exhibit greater bioactivity compared to monomeric anthocyanins, yet the lipid-lowering effects of pyranoanthocyanin Vitisin A, a primary derivative found in aged red wines, have not been extensively studied in vivo. This study evaluated the triglyceride-lowering effects of Vitisin A and its anthocyanin counterpart Cyanidin-3-O-glucoside (C3G) in both free fatty acid -induced HepG2 cells and high-fat diet-fed ApoE-/- mice, with a focus on their roles in lipid metabolism. In vitro, Vitisin A significantly reduced triglyceride levels and lipid accumulation in HepG2 cells compared to C3G at equivalent concentrate. In vivo, dietary supplementation with 100 mg/kg of Vitisin A reduced body weight gain and plasma triglyceride levels by 19.6% and 29.5%, respectively, whereas no significant effects were observed with C3G. Mechanistically, Vitisin A markedly inhibited hepatic de novo lipogenesis (DNL) by activating the AMPK/ACC signaling pathway and downregulating FASN expression. Concurrently, Vitisin A enhanced fatty acid β-oxidation more robustly than C3G by upregulating CPT-1A via AMPK/SIRT1/PGC-1α and PPAR-α/PGC-1α pathways. Both Vitisin A and C3G driving peroxisomal β-oxidation of very-long-chain fatty acids. In summary, Vitisin A demonstrated superior triglyceride-lowering effects compared to C3G, primarily through dual mechanisms of inhibiting hepatic DNL and enhancing fatty acid β-oxidation.

Protective Effects of Food-Derived Kaempferol on Pancreatic β-Cells in Type 1 Diabetes Mellitus

BACKGROUND

Kaempferol (KPF), a flavonoid abundant in edible plants, possesses potent anti-inflammatory and antioxidant properties beneficial with notable health benefits.

OBJECTIVE

To evaluate the protective effects of KPF on metabolic disturbances and pancreatic damage in a Type 1 diabetes mellitus (T1DM) mouse model.

METHODS

Male C57BL/6 mice were divided into normal, T1DM, T1DM + KPF 25 mg/kg, and T1DM + KPF 50 mg/kg groups. T1DM was induced by streptozotocin (STZ). KPF was administered via intraperitoneal injection for 2 weeks. After 4 weeks from the start, metabolic parameters, pancreatic histology, and plasma metabolites were analyzed. Network pharmacology and molecular docking identified key targets and pathways. In vitro, INS-1 cells were used to assess reactive oxygen species (ROS) production and apoptosis.

RESULTS

KPF significantly reduced blood glucose (GLU) and triglyceride (TG) levels, increased high-density lipoprotein (HDL) levels, and preserved pancreatic β-cell structure. Metabolomics revealed changes in energy metabolism and oxidative stress-related metabolites. Network analysis highlighted the PI3K/AKT/mTOR pathway, with strong binding affinities to targets such as AKT1. In vitro, KPF decreased ROS production in INS-1 cells; this effect was reversed by a PI3K/AKT inhibitor. KPF also reduced apoptosis in INS-1 cells.

CONCLUSIONS

KPF ameliorates metabolic disturbances and pancreatic damage in T1DM mice, suggesting potential as a functional food ingredient for diabetes management.

Kaempferol efficacy in metabolic diseases: Molecular mechanisms of action in diabetes mellitus, obesity, non-alcoholic fatty liver disease, steatohepatitis, and atherosclerosis

The incidence of metabolic diseases has progressively increased, which has a negative impact on human health and life safety globally. Due to the good efficacy and limited side effects, there is growing interest in developing effective drugs to treat metabolic diseases from natural compounds. Kaempferol (KMP), an important flavonoid, exists in many vegetables, fruits, and traditional medicinal plants. Recently, KMP has received widespread attention worldwide due to its good potential in the treatment of metabolic diseases. To promote the basic research and clinical application of KMP, this review provides a timely and comprehensive summary of the pharmacological advances of KMP in the treatment of four metabolic diseases and its potential molecular mechanisms of action, including diabetes mellitus, obesity, non-alcoholic fatty liver disease (NAFLD)/nonalcoholic steatohepatitis (NASH), and atherosclerosis. According to the research, KMP shows remarkable therapeutic effects on metabolic diseases by regulating multiple signaling transduction pathways such as NF-κB, Nrf2, AMPK, PI3K/AKT, TLR4, and ER stress. In addition, the most recent literature on KMP's natural source, pharmacokinetics studies, as well as toxicity and safety are also discussed in this review, thus providing a foundation and evidence for further studies to develop novel and effective drugs from natural compounds. Collectively, our manuscript strongly suggested that KMP could be a promising candidate for the treatment of metabolic diseases.