Abstract: Objective To investigate the effects of astaxanthin on chronic liver injury in rats and to explore the underlying mechanism. Methods Chronic liver injury in rats were induced by carbon tetrachloride injection,and the rats were randomly divided into control,model and astaxanthin group. The content of ALT,AST,ALP,TP in serum and superoxide dismutase （SOD）,glutathione-S-transfcrase （GST）,glutathione （GSH） and malondialdehyd （MDA） in liver tissues were detected. The collagensⅠmRNA were detected by RT-PCR. Results The collagens index in model group were （1.84±0.24）,much higher than in control [（0.42±0.12）,P<0.05],while the collagens index in astaxanthin group （0.89±0.12） decreased significantly（P<0.05） as compared to that in the model; The collagenⅠmRNA in model group（0.48±0.06） was higher than in control group（0.12±0.02）,while it decreased （0.35±0.09） in astaxanthin group （P<0.01） as compared to that in the model;In control group,the MDA,GST,GSH and SOD in liver tissues were （1.93±0.76） nmol/mg, （18.43±5.34） U/mg,（75.45±9.67） mg/g and （678.80±76.56） U/mg,respectively. They were（6.56±1.09） nmol/mg,（54.34±7.65） U/mg,（35.45±9.01） mg/g and （203.89±89.00 U/mg）,respectively. After treatment of astaxanthin,they were（3.34±1.12） nmol/mg,（30.89±4.78） U/mg,（56.78±7.78） mg/g and （432.34±92.56 U/mg）, respectively. ConclusionAstaxanthin could attenuate chronic liver injury in rats by improving the anti-oxidative stress.

Key words: Chronic liver injury, Astaxanthin, Protective effect, Oxidative stress