Abstract: Objective: To assess the effect of sibutramine, fenofibrate, metformin and topiramate on body weight, fat mass, fasting serum glucose, lipids, insulin and Ghrelin levels of obese rats induced by a high-fat diet. Methods: Thirty-five obese male Wistar rats were randomly divided into five groups. They were respectively treated with water, sibutramine（10mg/kg）, fenofibrate（83.4mg/kg）, metformin（400mg/kg）and topiramate（53.6mg/kg）and were also fed with a fat-rich diet for 8 weeks. Then they were executed and body weight, visceral fat mass, serum lipids, glucose, insulin and Ghrelin were determined. Results: Food intake and body weight were significantly decreased by fenofibrate and topiramate （P＜0.01， P＜0.01 and P＜0.01， P＜0.05)in obese rats. However, food intake was not significantly changed but body weight was significantly decreased by Metformin and sibutramine (P＜0.05， P＜0.01). Body fat mass was significantly decreased only by sibutramine and fenofibrate（P＜0.05， P＜0.01). There were no significant differences of serum lipids, glucose, insulin and Ghrelin among the groups（P＞0.05）. Conclusion: These four medicines are effective on reducing body weight in obese rats with a fat-rich diet, but have little effect on serum Ghrelin. Furthermore, sibutramine and fenofibrate can noticeably reduce fat mass.

Key words: Obesity, Sibutramine, Fenofibrate, Metformin, Topiramate, Ghrelin