Anti-obesity effects of lipase inhibitor CT-II, an extract from edible herbs, Nomame Herba, on rats fed a high-fat diet

OBJECTIVE: To investigate the inhibitory effects of CT-II, extract of Nomame Herba, on lipase activity in vitro and on obesity in rats fed a high-fat diet in vivo. DESIGN: The assay for the inhibitory effect of CT-II on lipase activity was performed by measuring released free fatty acids after the incubation of the medium with CT-II, porcine pancreatic lipase and triolein (experiment 1). In vivo experiments, lean rats or obese rats (570 - 718 g) were fed a high-fat diet containing 60% fat with or without CT-II for 8 weeks (experiment 2), for 14 days (experiment 3) or for 12 weeks (experiment 4), respectively. MEASUREMENT: The time course of body weight, food intake, organ weight (parametrial fat, liver, heart and kidney) and plasma parameters (triglyceride, total cholesterol, glucose, AST, ALT and insulin), fecal output of total fat and total cholesterol were measured. Hepatic histological examinations were also performed, RESULTS: CT-II inhibited the porcine lipase activity dose-dependently in vitro (experiment 1). Body and liver weight were reduced and hepatic histological examination showed an amelioration of fatty liver in CT II treated animals (experiment 2), CT-II significantly inhibited body weight gain and plasma triglyceride elevation in a dose-dependent manner, without affecting food intake in lean rats fed the high-fat diet. Elevated plasma AST and ALT were also decreased (experiment 3). When obese rats fed the high-fat diet were treated with CT-II for up to 6 months, body weight was initially reduced and thereafter weight gain was significantly suppressed. Total body fat was also significantly reduced and significant reduction of plasma AST and ALT was observed (experiment 4). CONCLUSIONS: These results demonstrated that the lipase inhibitor CT-II is effective in preventing and ameliorating obesity, fatty liver and hypertriglyceridemia in rats fed a high-fat diet.