[Study on therapeutic effects of metformin on rat fatty livers induced by high fat feeding].

OBJECTIVES: To explore the therapeutic effects of metformin on rat fatty livers induced by high fat feeding.

METHODS: A fatty liver model was established by feeding rats with a high caloric laboratory chow for 12 weeks, then the rats were randomly divided into three groups, i.e. model control group, metformin group and dietary treatment group. A normal control group was organized at the same time. The rats of the metformin group were given metformin 156 mg/kg/d while the other groups were given distilled water of the same volume by stomach feeding. The model control group rats were fed with high caloric laboratory chow while other groups were fed a normal diet. After four weeks, all the animals were sacrificed. Liver index (liver/body weight ratio), serum activities of liver-associated enzymes, blood lipids, liver triglycerides, fasting blood glucose, fasting plasma insulin, HOMA insulin resistance index (HOMA-IR), and the liver histology of rats of all groups were assayed.

RESULTS: The body weight, liver index, serum activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), gamma glutamyl transferase (GGT), total cholesterol (TC), triglycerides (TG) and liver triglycerides in the model group increased significantly, while HDL-cholesterol concentration decreased significantly. Fasting blood glucose, fasting plasma insulin and HOMA-IR showed an increasing tendency, but there was no significant difference of those indexes among the three groups. The liver histology in the model group showed moderate to severe steatosis, mainly as macro vesicle steatosis, lobular inflammatory, cell infiltration and necrosis. Compared with the model group, the levels of body weight, liver index, serum ALT, ALP, TC, TG and liver triglycerides in the metformin group were significantly lower and were similar to those of the normal group, while their HDL-cholesterol concentration was significantly higher. The liver histology in the metformin group was nearly normal. In the dietary treatment group, hyperlipidemia persisted, although liver index and GGT were lower and the liver histology changes were somewhat milder.

CONCLUSION: It is suggestive that metformin might be effective in treating rat fatty liver induced by high fat feeding.