Protective effects of Radix Isatidis polysaccharide ameliorates obesity via promotion AMPK pathway in high-fat-diet-induced obese rats and 3T3-L1 adipocyte cells.

OBJECTIVES: The purpose of this paper is to ascertain the effect and mechanism of Radix Isatidis polysaccharide (RIP) on obesity. METHODS: High fat diet (HFD)-induced obese rats and the MDI-induced 3T3-L1 adipocyte cells were established to evaluate the ameliorated obesity effect and mechanism from RIP. KEY FINDINGS: Experiments in vivo show that oral administration of RIP has significant preventive effects on HFD-induced obesity and metabolic disorders in rats. With treatment of RIP (20, 40 and 80 mg/kg BW), the body weight, fat accumulation, adipocyte cell size, serum lipid levels and antioxidant enzyme activity were progressively improved. On the other hand, the treatment of 3T3-L1 cells with RIP (25, 50 and 100 mg/L) led to a decrease in lipid accumulation and glucose consumption. In addition, during adipogenesis in 3T3-L1 cells, RIP remarkably down-regulated mRNA levels of peroxisome proliferator-activated receptor-γ (PPARγ), CCAAT/enhancer binding protein-α (C/EBPα), sterol regulatory element-binding protein-1c (SREBP-1c), fatty acid synthase (FAS), acetyl-CoA carboxylase and glycerol-3-phosphate dehydrogenase. Furthermore, after RIP treatment, the protein expression of PPARγ, C/EBPα, FAS, HMG-CoA reductase and acetyl-CoA synthetase-1 (AceCS1) were significantly decreased and the expression of p-AMPK was increased. CONCLUSION: These results highlight the potential of RIP for obesity interventions and suggest that RIP inhibited adipocyte differentiation and lipid synthesis by activating adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) signalling pathway and down-regulating the expression of major adipogenic transcription factors, PPARγ, C/EBPα, etc.

Effect of Radix isatidis polysaccharide on alleviating insulin resistance in type 2 diabetes mellitus cells and rats.

OBJECTIVES: The objective of this paper was to explore the effects of Radix isatidis polysaccharide (RIP) extracted from Radix isatis on alleviating insulin resistance. METHODS: The insulin resistance models of 3T3-L1 preadipocytes and type 2 diabetic rats were established to evaluate the insulin resistance activity of RIP. KEY FINDINGS: Radix isatidis polysaccharide within the concentration range of 25-100 µg/ml could reduce cell supernatant glucose and TNF-α levels (P < 0.01) and increase the expression of PI-3K P85, Glut4, IRS-1 and Akt protein in symptoms of IR 3T3-L1 preadipocytes. In the meantime, RIP contributed to relieve the weight loss of diabetic rats whose liver weight and liver index were decreased due to the effects of RIP. Experiments in rats also showed that RIP had capacity in reduced serum TC, TG, LDL-C, FFA, FBG, FINS, MDA, ALT, AST activities and increased serum HDL-C, SOD, ISI (P < 0.05 or 0.01). In addition, the oral glucose tolerance in rats was improved (P < 0.05) and liver damage was restored due to RIP. CONCLUSIONS: Radix isatidis polysaccharide significantly alleviates insulin resistance in 3T3-L1 preadipocytes and type 2 diabetic rats. These beneficial effects of RIP may associate with their roles in improving the glucose metabolism, lipid metabolism and oxidative stress.

Studies on anti-angiogenesis of ginsenoside structure modification HRG in vitro.

This study investigates the anti-angiogenic effect of 3ß, 12ß, 20(S)-trihydroxy dammarane-3-O-ß-d-glucopyranosyl(1-2)-ß-d-glucopyranoside(HRG), a new chemical compound obtained by structure modification on Ginseng saponins Rg3, associated with the regulation of matrix metalloproteinases(MMPs) and its upstream signal-regulated molecule of vascular endothelial growth factor(VEGF) and basic fibroblast growth factor(b-FGF) in vitro, which plays an critical role in angiogenesis during the process of carcinoma. In our study, to investigate the anti-angiogenesis effect of HRG in HUVECs, we utilized cell proliferation assay, tube formation assay, wound-healing assay, Semi-quantitative reverse transcription PCR, and Western blot assay. Our results demonstrated that HRG plays a major role in the regulation of proliferation, migration and tube formation of HUVECs by suppressing the expression of VEGF and b-FGF in both transcriptional and post-transcriptional levels. In addition, the expression of MMP-2 and MMP-9, which were related to the ECM degradation, were down-regulated after administration of HRG as well. Overall, our results revealed that HRG strongly inhibited the process of angiogenesis and shows better effectiveness than Rg3.

Anti-obesity action of Salix matsudana leaves (Part 1). Anti-obesity action by polyphenols of Salix matsudana in high fat-diet treated rodent animals.

In preliminary experiments, polyphenol fractions prepared from the leaves of Salix matsudana reduced the elevation of the rat plasma triacylglycerol level at 3 and 4 h after oral administration of a lipid emulsion containing corn oil, at a dose of 570 mg/kg. The present study examined the anti-obesity action of polyphenol fractions of S. matsudana leaves by testing whether the polyphenol fractions prevented the obesity induced by feeding a high-fat diet to female mice for 9 weeks. Body weights at 2-9 weeks and the fi nal parametrial adipose tissue weights were significantly lower in mice fed the high-fat diet with 5% polyphenols of S. matsudana leaves than in those fed the high-fat diet alone. The polyphenols of S. matsudana leaves also significantly reduced the hepatic total cholesterol content, which was elevated in mice fed the high-fat diet alone. In addition, the polyphenol fractions of S. matsudana leaves inhibited palmitic acid uptake into brush border membrane vesicles prepared from rat jejunum and alpha-amylase activity, and their fractions enhanced norepinephrine-induced lipolysis in fat cells. In conclusion, it is suggested that the inhibitory effects of the flavonoid glycoside fraction of S. matsudana leaves on high-fat diet-induced obesity might be due to the inhibition of carbohydrate and lipid absorption from small intestine through the inhibition of alpha-amylase and palmitic acid uptake into small intestinal brush border membrane or by accelerating fat mobilization through enhancing norepinephrine-induced lipolysis in fat cells.