Abstract: 【Objective】 The experiment was aimed to investigate the effect of alliin on the expression of cystathionine-β-synthase (CBS) and cystathionine-γ-lyase (CSE) in liver of mice with nonalcoholic fatty liver disease (NAFLD),in order to elucidate the pathway of action of alliin to improve NAFLD and provide scientific basis for clinical drug development.【Method】 Fifty male C57/6J mice were randomly divided into five groups:Normal group,model group,sodium hydrosulfide group,allicin group and allicin＋PAG group (DL-propargylglycine,PAG),with 10 mice in each group.The normal group was fed with normal feed and the other four groups were fed with high fat feed.The allicin group was given 20 mg/kg allicin by gavage.Allicin＋PAG group was given 20 mg/kg of allicin by gavage,and at the same time,15 mg/kg PAG was injected intraperitoneally.Sodium hydrosulfide group was injected with 2 mg/kg sodium hydrosulfide by intraperitoneal injection.Normal and model groups were given equal doses of distilled water by gavage,once a day,weighed once a week.After 6 weeks of prophylactic administration,mice were euthanized to observe liver morphology and pathological changes,and the serum total cholesterol (TC),triglyceride (TG),high density lipoprotein (HDL-C),and low density lipoprotein (LDL-C) were detected.The protein expression of CBS and CSE in liver of mice were detected by Western blotting.【Result】 Compared with normal group,the body weight of mice in model group was increased significantly (P＜0.05),there was no significant change in the body weight of mice in other groups (P＞0.05).Morphological observation results showed that the liver of mice in model group were yellowish,lusterless and flowery,while the liver of mice in the other groups had a smooth surface,uniform texture and a color close to that of mice in normal group.HE staining of liver pathology showed that the slices of the normal group were normal,while the model group showed obvious fat vacuoles and lipid droplet deposition,indicating that the fatty liver model was successfully established.Compared with model group,there was a significant improvement in sodium hydrosulfide group and the allicin group.Antilipidemic effect of allicin＋PAG group was weakened compared with allicin group.TG,TC and LDL-C in serum of mice were significantly higher in model group compared with normal group (P＜0.05),and TC and TG were significantly lower in all administered groups compared with model group (P＜0.05).Compared with normal group,the protein expression of CBS and CSE of mice were significantly decreased in model group (P＜0.05),and the protein expression of CBS and CSE in mice were significantly or extremely up-regulated in sodium hydrosulfide and allicin groups after the intervention (P＜0.05 or P＜0.01).There was no significant difference in the expression of CBS and CSE in the allicin ＋ PAG group compared with model group (P＞0.05).【Conclusion】 Allicin could significantly increase the expression of CBS and CSE in liver of NAFLD mice induced by high-fat diet,improve the indicators of lipids in serum,reduce the lipid deposition in mouse hepatocytes,and play a role in protecting the liver.

Key words: alliin; mice; nonalcoholic fatty liver disease (NAFLD); cystathionine-β-synthase (CBS); cystathionine-γ-lyase (CSE)