ABSTRACT
Objective: To examine the effect of Senna alata (S. alata) leaf extracts on the regulation of lipid metabolism in high-fat diet-induced obese mice. Methods: The obesity condition was induced in the male ICR mice by feeding them with high-fat diet (45 kcal% fat) for 12 weeks. At the 7th week of diet feeding, the obese mice were treated with the water extract of S. alata leaf at 250 and 500 mg/kg/day, respectively, that continued for six weeks. At the end of the treatment period, the biochemical parameters were determined. The hepatic histology and the gene and protein expressions were also examined. Results: In comparison with the obese control mice, the mice treated with S. alata showed a significant reduction in the elevated blood glucose levels and a decrease in the serum insulin and leptin levels. A reduction in the serum total cholesterol, triglyceride, non-esterified fatty acid, and hepatic triglyceride levels were also observed. The histological examination of the obese mice treated with S. alata showed a reduced lipid accumulation in the liver tissue. Hepatic lipogenic gene expression showed that S. alata decreased the activity of sterol regulatory element binding protein 1c, fatty acid synthase, and acetyl-CoA carboxylase. S. alata could suppress hepatic peroxisome proliferator-activated receptor gamma (PPARγ) protein. Moreover, the protein expression of PPARα in liver tissue was clearly increased by S. alata treatment. Conclusion: The treatment with S. alata could decrease several parameters of impaired lipid metabolism in the obese mice by downregulating sterol regulatory element binding protein 1c and PPARγ and upregulating PPARα. This study is the first report on the role of S. alata leaf extract in alleviating the abnormal lipid metabolism in obese conditions.
ABSTRACT
Objective: To investigate the effect of Rhinacanthus nasutus (R. nasutus) leaf extract on impaired glucose and lipid metabolism in obese ICR mice. Methods: Obesity was induced in the male ICR mice by feeding them a high-fat diet (60 kcal% fat) for 12 weeks. After the first six weeks of the diet, the obese mice were administered with the water extract of R. nasutus leaves at 250 and 500 mg/kg per day for the next six weeks. Subsequently, the blood glucose, lipid profiles, insulin, leptin, and adiponectin levels were measured. The liver and adipose tissues were excised for histopathological examination and protein expression study. Results: After six weeks of the treatment, R. nasutus extract (at 250 and 500 mg/kg per day) was found to reduce the elevated blood glucose level, improve the insulin sensitivity, decrease the serum leptin, and increase the serum adiponectin levels. The obese mice treated with R. nasutus were found to have a reduction in the increased lipid concentrations in their serum and liver tissues. Moreover, treatment with R. nasutus reduced the fat accumulation in the liver and the large adipocyte size in the fat tissues. Interestingly, the administration with R. nasutus extract was marked by an increase in the hepatic peroxisome proliferators-activated receptor alpha, fat cell adiponectin, and glucose transporter 4 proteins. Conclusions: To the best of our knowledge, the present study is the first report on the impact of R. nasutus extract in improving the impaired glucose and lipid metabolism in high-fat diet-induced obesity in mice via stimulating the insulin sensitivity in the liver and adipose tissues.