Effect of Thunbergia laurifolia water extracts on hepatic insulin resistance in high-fat diet-induced obese mice

Objective:To examine the effect of water extract of Thunbergia laurifolia on hepatic insulin resistance in high-fat diet-induced obese mice.Methods:High-fat diet with 45 kcal%lard fat was used for obesity induction in ICR mice.The mice were fed with high-fat diet for 16 weeks,and during the last 8 weeks,they were treated with 200 mg/kg/day of water extracts from Thunbergia laurifolia leaf,stem and flower.Serum biochemistry,liver histology,and protein expression were examined after the treatment.Results:Extracts from all of the three parts of Thunbergia laurifolia significantly alleviated hyperglycemia,hyperlipidemia,hyperinsulinemia,and hyperleptinemia.The stem and flower extracts improved glucose tolerance.All of the extracts significantly reduced serum TNFαand monocyte chemoattractant protein-1 levels.Liver weight,triglyceride levels,and lipid accumulation were also decreased.Moreover,hepatic glucose-6-phosphatase level was significantly decreased,while the levels of PPARα,phosphorylated AMPK,and phosphorylated Akt were significantly increased with treatment of Thunbergia laurifolia extracts.Conclusions:Thunbergia laurifolia extracts can ameliorate hepatic insulin resistance in high-fat diet-induced obese mice by improving glucose and lipid homeostasis,which may be associated with stimulating phosphorylation of AMPK and Akt pathways.

Effects of Brassica oleracea extract on impaired glucose and lipid homeostasis in highfat diet-induced obese mice

Objective: To examine the effect of Brassica oleracea extract(BO) on impaired glucose and lipid homeostasis in high-fat diet(HFD)-induced obese mice. Methods: Obesity of ICR mice was induced by feeding a HFD(45 kcal% lard fat) for 16 weeks. During the last 8 weeks of study period, obese mice were additionally administered with BO(100 and 200 mg/kg/day). The metabolic parameters were determined. The gene expressions of hepatic lipogenesis were also studied. Results: After 8 weeks of treatment, BO(100 and 200 mg/kg) significantly reduced hyperglycemia and improved insulin sensitivity(P < 0.05). The serum lipid(total cholesterol, triglyceride, and non-esterified fatty acid) and hepatic triglyceride and nonesterified fatty acid were decreased(P < 0.05). The levels of insulin and leptin in serum were also decreased(P < 0.05). Moreover, the expressions of hepatic lipogenic genes including sterol regulatory element-binding protein 1 c, fatty acid synthase, and acetyl-CoA carboxylase were decreased by BO treatment(P < 0.05). Conclusions: These results suggest that BO is a new therapeutic agent for improving the homeostasis of glucose and lipid in HFD-induced obese mice probably by suppression of lipogenic genes in liver tissue.