ABSTRACT
Objective To investigate the effects of S-allylcysteine ( SAC ) , on nitric oxide ( NO ) production and antioxidant enzyme activities in hyperlipidemic rats. Methods Male Wistar rats were randomly divided into seven groups. Five groups including normal control group ( normal diet) , model control group ( high-fat diet, HFD) and SAC low,medium,high treated group (high-fat diet +25,50,100 mg·kg-1 SAC) were sacrificed after 4 weeks dosing,while the other two groups including L-arginine group (normal diet+ 20 mg·kg-1 L-arginine) and SAC+L-arginine group (50 mg·kg-1 SAC+20 mg·kg-1 L-arginine) were sacrificed at 4 h after dosing. The serum, livers and kidneys were collected. The levels of NO, the activities of nitric oxide synthase ( NOS ) , antioxidant enzymes in vivo and L-arginine contents in serum were determined. Results Comparing with model control group, the activities of total NOS in serum and liver were significantly reduced in SAC-treated groups (P<0. 05). The level of L-arginine in SAC-treated groups was (8. 25 ± 1. 15), (7. 76 ± 1. 24) and (7. 22 ± 1. 64)μg·mL-1 , respectively. Compared with model control group, the level of L-arginine were significantly reduced in SAC-treated groups (P<0. 05). Comparing with L-arginine group, the activities of total NOS (T-NOS) and iNOS were reduced in SAC+L-arginine group. SAC treatment (100 mg·kg-1) significantly increased the activities of superoxide dismutase (SOD) (P<0. 01) and the level of glutathione (GSH) (P<0.01), and decreased the level of malondialdehyde (MDA) in serum and liver of hyperlipidemic rats. Conclusion These data suggest that SAC inhibits the NO production by reducing iNOS activity, arginine concentration and exhibited antioxidant activity, which may play a pharmacologically important role in protection from oxidative injury and pathogenesis of atherosclerosis.