Abstract: [Objective] This study was aimed to investigate the effect of crude polysaccharide from Melastoma dodecandrum Lour. on lipid metabolism in obese mice induced by high-fat diet. [Method] The mice were randomly divided into 6 groups, including blank group, model group, positive group (0.025 mg/g orlistat), high, medium and low dose of crude polysaccharide from Melastoma dodecandrum Lour. groups (1.2, 0.6 and 0.3 mg/g), with 12 mice in each group. The mice in blank group were fed with normal maintenance diet, the mice in the other groups were fed with high-fat diet, the mice in blank group and model group were given normal saline, the mice in positive group were given 0.025 mg/g orlistat, and the mice in high, medium and low dose groups were given 1.2, 0.6 and 0.3 mg/g crude polysaccharides of Melastoma dodecandrum Lour., once a day for 30 days. The weight of mice, epididymis, fat around kidney and liver tissuea were measured. The pathological changes of fat and liver were observed by HE staining. Serum total cholesterol (TC), triglyceride (TG), low density lipoprotein (LDL-C), high density lipoprotein (HDL-C) and liver TC and TG were detected by biochemical method. The relative expression of acetyl CoA carboxylase 1 (ACC1) gene in liver was determined by Real-time quantitative PCR. [Result] Compared with model group, the body weight, Lee's index, food intake, the weight of liver, epididymis fat and kidney fat were significantly decreased in the high and medium dose groups (P<0.05). The body weight and fat weight of mice in low dose group had no significant change (P>0.05), the food intake and liver weight of mice in positive group had no significant change (P>0.05). The fat index of mice in positive and high dose groups was significantly decreased (P<0.05). The contents of serum TC, TG, LDL-C and liver TC, TG in positive and high dose groups were significantly decreased (P<0.05), but there was no significant difference of serum HDL-C (P>0.05). The contents of TC, TG in serum and TC in liver were significantly decreased in middle dose group (P<0.05). In positive group, high, medium and low dose groups, the adipocytes were reduced in varying degrees, and the lipid droplets and vacuoles in hepatocytes were significantly reduced (P<0.05), and the relative expression of ACC1 gene was significantly down regulated (P<0.05) by 20%, 42%, 15% and 11%, respectively. [Conclusion] The crude polysaccharide of Melastoma dodecandrum Lour. could intervene the occurrence of obesity by regulating the level of lipid metabolism in obese mice induced by high-fat diet.

Key words: Melastoma dodecandrum Lour.; crude polysaccharide; obesity; lipid metabolism