METHODS: The petroleum ether, chloroform and methanol extracts of F. deltoidea were prepared and subjected to standardization using preliminary phytochemical and HPLC analysis. Dose selection was made on the basis of acute oral toxicity study (50-5000 mg/kg b. w.) as per OECD guidelines. Diabetes mellitus was induced with streptozotocin and rats found diabetic were orally administered with the extract (250, 500 and 1000 mg/kg) for 14 days. Levels of blood glucose and insulin were measured in control as well as diabetic rats on 0, 7 and 14th day. In addition, glucose metabolism regulating gene expression was assessed using RT-PCR.
RESULTS: HPLC analysis revealed that the methanol extract is enriched with C-glycosylflavones particularly, vitexin and isovitexin. In oral glucose tolerance test, oral administration of the methanol extract increased the glucose tolerance. The methanol extract showed significant (P insulin secretion which impeded the hepatic glucose production, via down-regulation of phosphoenolpyruvate carboxykinase and glucose-6-phosphatase genes expression on one hand, and up-regulation of hepatic GK and PPARγ genes expression on the other hand. The extract caused an increased expression of GLUT-4 gene expression in skeletal muscles which leads to normalize the hyperglycemia. The extract also nullified the toxic effects of streptozitocin by blocking its entry into the islet β-cells through reducing the expression of GLUT-2 gene.
CONCLUSION: It can be concluded that, F. deltoidea could potentially inhibits the streptozitocin-induced hyperglycemia in rats. Further the herb can be utilized as useful remedy for alleviation of diabetes complications.
MATERIALS AND METHODS: In silico target prediction was first employed to predict the probability of the polyphenols interacting with key protein targets related to insulin signalling, based on a model trained on known bioactivity data and chemical similarity considerations. Next, CA was investigated in in vivo studies where induced type 2 diabetic rats were treated with CA for 28 days and the expression levels of genes regulating insulin signalling pathway, glucose transporters of hepatic (GLUT2) and muscular (GLUT4) tissue, insulin receptor substrate (IRS), phosphorylated insulin receptor (AKT), gluconeogenesis (G6PC and PCK-1), along with inflammatory mediators genes (NF-κB, IL-6, IFN-γ and TNF-α) and peroxisome proliferators-activated receptor gamma (PPAR-γ) were determined by qPCR.
RESULTS: In silico analysis shows that several of the top 20 enriched targets predicted for the constituents of CA are involved in insulin signalling pathways e.g. PTPN1, PCK-α, AKT2, PI3K-γ. Some of the predictions were supported by scientific literature such as the prediction of PI3K for epigallocatechin gallate. Based on the in silico and in vivo findings, we hypothesized that CA may enhance glucose uptake and glucose transporter expressions via the IRS signalling pathway. This is based on AKT2 and PI3K-γ being listed in the top 20 enriched targets. In vivo analysis shows significant increase in the expression of IRS, AKT, GLUT2 and GLUT4. CA may also affect the PPAR-γ signalling pathway. This is based on the CA-treated groups showing significant activation of PPAR-γ in the liver compared to control. PPAR-γ was predicted by the in silico target prediction with high normalisation rate although it was not in the top 20 most enriched targets. CA may also be involved in the gluconeogenesis and glycogenolysis in the liver based on the downregulation of G6PC and PCK-1 genes seen in CA-treated groups. In addition, CA-treated groups also showed decreased cholesterol, triglyceride, glucose, CRP and Hb1Ac levels, and increased insulin and C-peptide levels. These findings demonstrate the insulin secretagogue and sensitizer effect of CA.
CONCLUSION: Based on both an in silico and in vivo analysis, we propose here that CA mediates glucose/lipid metabolism via the PI3K signalling pathway, and influence AKT thereby causing insulin secretion and insulin sensitivity in peripheral tissues. CA enhances glucose uptake and expression of glucose transporters in particular via the upregulation of GLUT2 and GLUT4. Thus, based on its ability to modulate immunometabolic pathways, CA appears as an attractive long term therapy for T2DM even at relatively low doses.
METHODS: Seventy-six obese subjects were randomly placed into two groups. The first group received three daily 120 mg dosages of orlistat for nine months (n=39), and the second group received a once daily 10 or 15 mg dosage of sibutramine for nine months (n=37). Baseline measurements for weight, body mass index (BMI), waist circumference (WC), body fat percentage (BF), visceral fat (VF), adiponectin, fasting plasma glucose (FPG), fasting insulin, pancreatic B cell secretory capacity (HOMA%B), insulin sensitivity (HOMA%S), insulin resistance (HOMA-IR) and serum high sensitivity C-reactive protein (hs-CRP) were performed and repeated during the sixth and ninth months of treatment.
RESULTS: Twenty-four subjects completed the trial in both groups. For both groups, weight, BMI, WC, BF, VF, HOMA-IR and hs-CRP were significantly lower at the end of the nine month intervention. However, there were no significant differences between the two groups for these parameters with nine months treatment. There was a significant decrease in FPG in orlistat group; while fasting insulin and HOMA%B reduced in sibutramine group. For both groups, there were also significant increases in adiponectin levels and HOMA%S at the end of the nine month intervention.
CONCLUSION: Nine months of treatment with orlistat and sibutramine not only reduced weight but also significantly improved BMI, WC, BF, VF, FPG, adiponectin, fasting insulin, HOMA%B, HOMA%S, HOMA-IR and hs-CRP. These improvements could prove useful in the reduction of metabolic and cardiovascular risks in obese subjects.
PURPOSE: The present study investigated the effects of oral treatment with M. pumilum var. alata (MPA) extracts on the estrogen receptor, metabolic characteristics and insulin signaling pathway in pancreas and liver of ovariectomised nicotidamide streptozotocin-induced diabetes in female rats.
MATERIALS AND METHODS: Ovariectomised diabetic (OVXS) Sprague-Dawley rats were orally administered with either aqueous leaf extract and ethanol (50%) stem-root extract of MPA (50 or 100 mg/kg) respectively for 28 days. Metabolic parameters were evaluated by measuring fasting blood glucose, serum insulin, oral glucose and insulin tolerance test. Distribution and expression level of insulin, oxidative stress and inflammatory marker in the pancreatic islets and liver were evaluated by immunohistochemistry and western blot, respectively.
RESULTS: Oral treatment with aqueous leaf and ethanol (50%) stem-root extracts of MPA (100 mg/kg) significantly reversed the elevated fasting blood glucose, impaired glucose and insulin tolerance. The protein expression of insulin, glucose transporter (GLUT-2 and GLUT-4) increased in the pancreatic islets and liver. Furthermore, marked improvement in the tissue morphology following treatment with MPA was observed. Similarly, the western blots analysis denotes improved insulin signaling in the liver and decreased reactive oxygen species producing enzymes, inflammatory and pro-apoptotic molecules with MPA treatment.
CONCLUSIONS: Taken together, this work demonstrate that 100 mg/kg of aqueous leaf extract and ethanol (50%) stem-root extract of MPA improves β-cell function and insulin signaling in postmenopausal diabetes through attenuation of oxidative stress and partially mediated by oestrogen receptor stimulation.
METHODS: AE was administered to streptozotocin (STZ)-induced diabetic rats twice daily at three doses (1000, 500, and 250 mg/kg b.w.) for 12 days p.o. Several biochemical analyses and a histological study of the pancreas and liver were performed, accompanied by a cell culture assay.
RESULTS: As compared to diabetic control (DC), AE at the doses of 500 and 1000 mg/kg b.w. caused significant reduction (p < 0.05) of blood glucose, total cholesterol and triglycerides levels, with positive improvement of serum insulin levels. Interestingly, immunohistochemical staining of the pancreas suggested no β-cell regeneration, despite significant increase in insulin production. AE-treated groups, however, showed overall restoration of the hepatic histoarchitecture of STZ-induced liver damage, suggesting a possible hepatoprotective effect. The pancreatic effect of AE was further studied through RIN-5F cell culture, which revealed a positive stimulatory effect on insulin release at a basal glucose concentration (1.1 mM).
CONCLUSION: Nypa fruticans Wurmb. vinegar's aqueous extract exerts its antihyperglycaemic activity, at least in part, through insulin stimulatory and hepatoprotective effects.
METHODS: Two parameters were measured (i) rate of glucose uptake by 3T3-L1 adipocyte cells in-vitro (ii) degree of pancreatic destruction in streptozotocin-nicotinamide induced male diabetic rats receiving M. pumilum aqueous extract (M.P) (250 and 500mg/kg/day) as reflected by levels of pancreatic oxidative stress, inflammation and apoptosis. In the meantime, phyto-chemical compounds in M.P were also identified by using LC-MS.
RESULTS: M.P was found able to enhance glucose uptake by 3T3-L1 adipocyte cells in-vitro while its administration to the male diabetic rats causes decreased in the fasting blood glucose (FBG), glycated haemoglobin (HbA1c), total cholesterol (TC), triglycerides (TG), low-density lipoprotein (LDL) levels but causes increased in insulin and high-density lipoprotein (HDL) levels, to near normal. Levels of oxidative stress in the pancreas as reflected by levels of lipid peroxidation product (LPO) decreased while levels of anti-oxidantive enzymes (SOD, CAT and GPx) in pancreas increased. Additionally, levels of inflammation as reflected by NF-κB p65, Ikkβ and TNF-α levels decreased while apoptosis levels as reflected by caspase-9 and Bax levels decreased. Anti-apoptosis marker, Bcl-2 levels in pancreas increased.
CONCLUSIONS: The ability of M.P to enhance glucose uptake and reduces pancreatic complications could account for its beneficial effects in treating DM.
METHODS: PCOS was induced in rats except for normal control by administering LTZ at 1 mg/kg/day for 21 days. Methanolic extract of F. deltoidea leaf was then orally administered to the PCOS rats at the dose of 250, 500, or 1000 mg/kg/day, respectively for 15 consecutive days. Lipid profile was measured enzymatically in serum. The circulating concentrations of reproductive hormone and antioxidant enzymes were determined by ELISA assays. Ovarian and uterus histomorphometric changes were further observed by hematoxylin and eosin (H&E) staining.
RESULTS: The results showed that treatment with F. deltoidea at the dose of 500 and 1000 mg/kg/day reduced insulin resistance, obesity indices, total cholesterol, triglycerides, low-density lipoprotein cholesterol (LDL), malondialdehyde (MDA), testosterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) to near-normal levels in PCOS rats. The levels of high-density lipoprotein cholesterol (HDL), estrogen, and superoxide dismutase (SOD) are also similar to those observed in normal control rats. Histomorphometric measurements confirmed that F. deltoidea increased the corpus luteum number and the endometrial thickness.
CONCLUSIONS: F. deltoidea can reverse PCOS symptoms in female rats by improving insulin sensitivity, antioxidant activities, hormonal imbalance, and histological changes. These findings suggest the potential use of F. deltoidea as an adjuvant agent in the treatment program of PCOS.