Effects of quercetin on polycystic ovary syndrome in animal models: a systematic review and meta-analysis.

BACKGROUND: Metformin is an insulin sensitizer that is widely used for the treatment of insulin resistance in polycystic ovary syndrome patients. However, metformin can cause gastrointestinal side effects. PURPOSE: This study showed that the effects of quercetin are comparable to those of metformin. Therefore, this study aimed to systematically evaluate the efficacy of quercetin in treating PCOS. METHODS: The present systematic search of the Chinese National Knowledge Infrastructure (CNKI), Wanfang Data Information Site, Chinese Scientific Journals Database (VIP), SinoMed, Web of Science, and PubMed databases was performed from inception until February 2024. The methodological quality was then assessed by SYRCLE's risk of bias tool, and the data were analyzed by RevMan 5.3 software. RESULTS: Ten studies were included in the meta-analysis. Compared with those in the model group, quercetin in the PCOS group had significant effects on reducing fasting insulin serum (FIS) levels (P = 0.0004), fasting blood glucose (FBG) levels (P = 0.01), HOMA-IR levels (P < 0.00001), cholesterol levels (P < 0.0001), triglyceride levels (P = 0.001), testosterone (T) levels (P < 0.00001), luteinizing hormone (LH) levels (P = 0.0003), the luteinizing hormone/follicle stimulating hormone (LH/FSH) ratio (P = 0.01), vascular endothelial growth factor (VEGF) levels (P < 0.00001), malondialdehyde (MDA) levels (P = 0.03), superoxide dismutase (SOD) levels (P = 0.01) and GLUT4 mRNA expression (P < 0.00001). CONCLUSION: This meta-analysis suggested that quercetin has positive effects on PCOS treatment. Quercetin can systematically reduce insulin, blood glucose, cholesterol, and triglyceride levels in metabolic pathways. In the endocrine pathway, quercetin can regulate the function of the pituitary-ovarian axis, reduce testosterone and luteinizing hormone (LH) levels, and lower the ratio of LH to follicle-stimulating hormone (FSH). Quercetin can regulate the expression of the GLUT4 gene and has antioxidative effects at the molecular level.

Effects of food restriction and/or aerobic exercise on the GLUT4 in type 2 diabetic male rats.

BACKGROUND: The aim of present study was to compare the effects of negative energy balance with food restriction and/or aerobic exercise on the glucose, insulin, and GLUT4 levels in diabetic male rats. METHODS: Fifty-six 10-week old male Wistar rats were randomly assigned to seven groups: a non-diabetic (ND) group and six diabetic groups. After an infusion of type 2 diabetes, the diabetic groups were given labels as well, namely diabetic control (DC) group, exercise (Ex) group, food restriction with standard diet (FRSD) group, food restriction with low-carbohydrate diet (FRLCD) group, food restriction with standard diet combination in exercise (FRSDE) group, and food restriction with low-carbohydrate diet combination in exercise (FRLCDE) group. Further, to induce caloric restriction (CR), food intake was reduced by 20% and given to food restriction consists of both of (FRSD and FRLCD). Hundred percent food consumption for the Ex group was fixed, but instead, 20% of their energy intake in exercise was calculated, and time of daily exercise was determined. Finally, a combination of reduced food intake (10%) and exercise (10%) was applied in each group FRSDE and FRLCDE for 8 weeks. RESULTS: The results showed that type 2 diabetes inductions had reduced glucose, insulin, and GLUT4 gene expression compared to the ND group (P = 0.001). However, there were significant differences in GLUT4 gene expression between groups after 8 weeks of intervention (P = 0.001). A post hoc least significant difference test show that compared to DC group, GLUT4 gene expression level of Ex, FRSDE, and FRLCDE groups was significantly increased 47% (P = 0.004), 60% (P = 0.001), and 65% (P = 0.001), respectively after 8 week of intervention, but it was not significant or with any other diabetic groups (P > 0.05). Moreover, glucose levels were significantly higher in the FRLCDE, FRLCD, FRSD, FRSDE, Ex groups compared with the DC group in the same period (P = 0.0.01). CONCLUSIONS: It was concluded that FRSD and FRLCD combination in regular exercise was elevated of GLUT4 gene expression in type 2 diabetes. These results may help to develop new methods for the treatment of obesity and type 2 diabetes mellitus.

Influences of Chinese Herbal Medicine Compound on Insulin and Frame Muscle Glucose Transport 4 Gene Expression of Type 2 Diabet in Rat / 中国中医药信息杂志

Objective To investigate the mechanism of Chinese herbal medicine compound Tang Mai Ping (TMP) capsule to type 2 diabet in rats. Methods The models of type 2 diabetic rats were established by injecting lower dosage of streptozotocin (STZ, 35 mg/kg) to belly, and fed high sucrose and high fat diet. Modle rats were randomly divided into model group, TMP group, and Erjiashuanggu (EJS) group, at the same time normal control. The content of plasma insulin was detected by radio-immunicy, mRNA expressing of frame muscle of Glucose Transporter 4 (GluT4) gene was detected with hyvirdism in situ. Results After built model, levels of insulin were obviously ascended in rats, but the expression of GluT4 mRNA lower significantly (P

Coordinate Regulation of Contraction Signal-Induced GLUT4 Transcription by CaMK and AMPK Signaling Pathways in Cultured Skeletal Muscle Cells / 生物化学与生物物理进展

Glucose transporter 4 (GLUT4), a major contributor to glucose transport in skeletal muscle, is closely related to diabetic treatment. Exercise regulates apparently GLUT4 gene expression which produces many beneficial metabolic adaptations for diabetic patients. Study has shown that both AMPK (AMP-activated protein kinase) and CaMK (calcium-calmodulin dependent protein kinase) signaling pathways are involved in regulation of exercise-induced GLUT4 gene expression in skeletal muscles, but the relationship between these two signaling pathways in regulating the GLUT4 gene is unclear. The purpose of the following study was to investigate the relationship of these two pathways in Caffeine- and AICAR-stimulated skeletal muscle cells GLUT4 gene expression. Muscle contractile activity results in increases in both cytosolic Ca2+ and AMPK activity. To mimic this response, primary cultured rat skeletal muscle cells were treated with Caffeine to raise cytosolic Ca2+ and with AICAR to activate AMPK. The muscle cells were divided into different groups (Control, AICAR, Caffeine, AICAR/Caffeine, Caffeine +Compound C, AICAR/Caffeine +Compound C, AICAR +KN93, AICAR/Caffeine + KN93), which were used for experiments of stimulation by AICAR and Caffeine, inhibition by AMPK inhibitor, Compound C and CaMK inhibitor, KN93 respectively. The results showed that both AICAR and Caffeine induced about 2- and 3-fold increases respectively (P

The effect of the resistin-binding peptide (RBP) on the 3T3-L1 adipocyte differentiation,lipid metabolism and GLUT-4 gene expression / 中国糖尿病杂志

Objective To investigate the effect of RBP on 3T3-L1 adipocyte differentiation,lipid metabolism and glucose transporter 4(GLUT-4)gene expression.Methods We constructed an expression vector for rat resistin gene and transfected it into 3T3-L1 adipocytes.RBP was added to the medium of 3T3-L1 adipocytes or resistin-overexpressing adipocytes on day 0 of differentiation.Cell differentiation and lipid accumulation were determined by oil red O staining.The mRNA expressions of differentiation marker genes(pref-1,C/EBP?,FAS)and GLUT-4 gene were evaluated by RT-PCR.Triglyceride(TG)and free fatty acids(FFAs)in adipocytes were measured by colorimetric kit.Results(1)When 10-12mol/L RBP was applied,the percent of living cells was high and the shape was unchanged.(2)RBP had no effect on the differentiation of normal adipocytes,but significantly decreased the number of lipid droplets in resistin-overexpressing adipocytes without affecting the lipid droplets-presenting day.(3)C/EBP? and FAS expressions in resistin-overexpressing adipocytes were down-regulated after RBP was applied,without changing their expressions in normal adipocytes.(4)RBP had no effect on the cellular TG and FFAs levels in normal cells,whereas it can significantly decrease the levels in resistin-overexpressing adipocytes.(5)There was no difference in the expression of GLUT-4 gene between 3T3-L1 adipocytes and RBP-applied cells.Conclusions(1)RBP has no effect on the cell differentiation and lipid metabolism in normal 3T3-L1 adipocytes.(2)RBP can inhibit the cell differentiation and lipid metabolism of resistin-overexpressing 3T3-L1 cells.(3)RBP has no effect on the expression of GLUT-4 gene.