Abstract: OBJECTIVE: To investigate the optimal dosage ratio of chlorogenic acid and gardenia glycosides in treating the rates with fatty liver disease induced by high-fat feed.METHODS: A rat model of non-alcoholic fatty liver disease(NAFLD) was established by using a high-fat diet. According to mathematical model "uniform design", varying doses of chlorogenic acid and gardenia glycosides have been combined to form 6 medications for the treatment of NAFLD.Samples were then taken to observe pathological changes of the liver tissue(HE staining); changes in the fat metabolism pathway e.g. triglyceride(TG)and free fatty acid(FFA) content; alterations in liver function, i.e. serum alanine aminotransferase(ALT)and aspartate aminotransferase(AST) activity; and differences in Malondialdehyde(MDA) and superoxide dismutase(SOD) content in the liver tissue. Multiple regression analysis was conducted to test the optimal dosage ratio of chlorogenic acid and gardenia glycosides.RESULTS: Fatty degeneration and vacuole-like changes of different degrees occurred in hepatic cells of the model group. Markers for fat metabolism, serum ALT and AST activities, and expression of MDA in liver tissue significantly increased, while SOD decreased. Combination of 90 mg chlorogenic acid and 90 mg Gardenia glycosides was the optimal dosage ratio of chlorogenic acid and gardenia glycosides in the treatment of rats with fatty liver induced by high-fat diet.CONCLUSION: Chlorogenic acid of 90 mg plus gardenia glycosides of 90 mg was the best combination in the treatment of fatty liver disease in rats induced by high-fat feed.

Key words: Chlorogenic acid, Gardenia glycosides, Non-alcoholic fatty liver disease, Uniform design method, Dose optimization