The present invention relates to a use of a composition comprising Solanum Nigrum L water extract reducing body weight and decreasing body fat, wherein the composition further relates to treatment or prevention of steatohepatitis.本發明提供一種組合物包含龍葵水萃取物用於降低體重和降低體脂肪之用途,其中該組合物進一步用於治療或預防脂肪肝炎。