새싹채소가 3T3-L1 지방세포와 흰쥐의 비만억제효과

Abstract

This study was performed to investigate the effect of ethanol extract of vegetable sprout on the differentiation of 3T3-L1 preadipocytes in vitro, and anti-obesity effect in rats fed normal or high fat diet in vivo. In order to develop development of the anti-obesity natural plant materials, the inhibitors of adipocytes differentiation were screened from vegetable sprout ethanol extracts such as broccoli, alfalfa, barely, rapeseed, red radish, red brussels, chinese cabbage and buckwheat. Treatment of broccoli sprout ethanol extracts(50 μg/mL) among the vegetable sprout ethanol extracts decreased differentiation and proliferation, and blocked accumulation of triglyceride in 3T3-L1 preadipocytes. Thus, an ethanol extract of brassica oleracea(BO) was selected as a candidate of adipocytes differentiation inhibitor. Therefore, this study was also conducted to investigate the anti-obesity effect of an ethanol extract of BO on the high fat diet-induced obese rats in vivo. Male Sprague-Dawley rats were fed 20%(w/w) high fat diet for 4 weeks to induce obesity. Experimental groups were normal diet(N), high fat diet(HF), normal diet and BO with 200 mg/kg treated group(NBL), normal diet and BO with 400 mg/kg treated group(NBH), high fat diet and BO with 200 mg/kg treated group(HBL), and high fat diet and 400 mg/kg treated group(HBH). After feeding of an ethanol extract of BO, adipose tissue heparin-releasable lipoprotein lipase(HR-LPL) and total extractable lipoprotein lipase(TE-LPL) activities, serum and liver lipid profiles were measured. The body weight gain was increased by high fat diet, but gradually decreased to the corresponding level of the normal diet group by administered BO extract. There was a signigicant increase in the activities of serum alanine aminotransferase(ALT), asparate aminotransferase (AST) and alkaline phosphatase(ALP) in the high fat diet group. The administration of BO ethanol extract decreased serum ALT, AST and ALP activities in dose dependent manners. Concentrations of serum total cholesterol, LDL-cholesterol, triglyceride and the atherogenic index were tended to be decreased in the BO ethanol extract administered groups compared with the high fat diet group. However, HDL-cholesterol and phospholipid concentrations in serum decreased in the high fat diet group and markedly increased by the BO ethanol extract administered groups. In addition, significantly increased levels of triglyceride, total cholesterol, LDL-cholesterol in the serum of HF were returned to the normal or even below the normal by administering of an ethanol extract of BO. There were no differences in the concentrations of serum triglyceride, phospholipid, LDL-cholesterol, HDL-cholesterol and free cholesterol between normal diet groups. Concentrations of total cholesterol and triglyceride in liver were also markedly decreased in the BO administered groups. Total cholesterol and triglyceride concentrations of adipose tissue in the BO administered groups were also decreased compared with the high fat diet group. In addition, there were no differences in the concentrations of liver and adipose tissue triglyceride and total cholesterol between normal diet groups. The increased activities of HR-LPL and TE-LPL in adipose tissue by high fat diet were decreased to the activity of normal group by administering of an ethanol extract of BO, as a dose-dependant manner. There were no differences between normal diet group and with BO 400 mg/kg treated group in HR-LPL and TE-LPL activities of adipose tissue. Taken together, it is suggested that the extract of BO decreases differentiation and proliferation, and blocked accumulation of triglyceride in 3T3-L1 preadipocytes, and leads to the decreased LPL activity and triglyceride concentration in high fat diet-induced obese rats, thereby potentially reducing lipid storage.