Ethanolic extract of cashew apple inhibits lipid metabolism and ameliorates obesity in atherogenic diet-induced obese rats

Abstract

Objective: To evaluate the anti-obesity activity of ethanolic extract of cashew apple using various in vitro and in vivo models. Methods: Phytochemical screening was carried out in ethanolic extract of cashew apple, followed by quantification of phenol and flavonoid. Antioxidant potential was evaluated using 2,2-diphenyl-1-picrylhydrazyl and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) scavenging assays. The inhibitory effect of ethanolic extract of cashew apple on α-amylase and pancreatic lipase was also studied. In addition, anti-obesity activity was determined in two in vivo models, lipid emulsion model and atherogenic diet-induced obese rat model. Levels of postprandial plasma triglycerides were assessed in lipid emulsion model, whereas serum lipid profile, in vivo antioxidants and histopathological studies of the carotid artery and liver were performed in an atherogenic diet-induced obese model. Results: Phytochemical screening revealed the presence of carbohydrates, alkaloids, polyphenols, terpenoids, and steroids. The in vitro assays showed inhibition of α-amylase and pancreatic lipase and strong antioxidant potential. Ethanolic extract of cashew apple showed significant and time- dependent inhibitory activity on postprandial triglycerides after administration of lipid emulsion for 5 h. Ethanolic extract of cashew apple at 200 and 400 mg/kg on day 60 showed a significant reduction in body weight, body mass index and atherogenic index, whereas lipid profile and liver function marker levels in the serum were decreased in a dose-dependent manner at time intervals (day 0, 20, 40, and 60) compared to the atherogenic diet-induced obese rats. Histological observations showed reduced non-alcoholic fatty liver deposits and decreased atherosclerotic fatty streak plaques (carotid artery) after treatment with ethanolic extract of cashew apple. Conclusions: Ethanolic extract of cashew apple ameliorates obesity, which may be partly mediated by its delayed absorption of cholesterol and carbohydrates.