The regulatory effects of curcumin on oxidation and antioxidation in non-alcoholicsteatohepatitis

Abstract

Objective To explore the regulatory effects of cucumin onoxidation and antioxidation in non-alcoholic steatohepatitis (NASH). Methods Fifty-six clean male rats were randomly divided into 7 groups by random numbers table. Eight rats in normal control group were fed by normal diet for 12 weeks. Twenty-four rats in model group were fed by choline dificinet (CD) diet and randomly sacrificedat week 4, 8 and 12 with 8 rats each time point.Twenty-four rats incucumin treatment group were given cucumin at high (500 mg/[kg·d]), medium (100 mg/[kg·d]) and low (50 mg/[kg·d]) dosages with 8 rats each dosage from week 5 of CD diet for 8 weeks, and the rats were sacrificed at week 12. The liver tissues were reserved for pathology test and detections of thiobarbituric acid reactive substances (TBARS), glutathione (GSH), the activities of superoxide dismutase (SOD), manganese superoxide dismutase (MnSOD), glutathione peroxidase (GPx), and levels of triglyceride (TG) and total cholesterol (TC). The measurement data with normal distribution were analyzed using t test, and the data with non-normal distribution were analyzed using rank sum Z test. Results The liver of rats presented with the performance of NASH when fed with CD diet for 4 weeks, and presented with early fibrosis after 8 weeks of CD diet, even progressed to cirrhosis after 12 weeks of CD diet.The NAS scores of medium and high dose curcumin treatment groups were 6.50 (5.25, 7.00) and 6.00 (5.00, 6.75), respectively, which were both lower than that model group at week 12 (8.00 [7.00, 8.00])(Z=2.441 and 2.728, respectively, both P 0.05). TG and TC levels in liver tissues of rats in low, medium and high doses treatment group were not significantly different compared with model group at week 12(TG: t=0.54, 1.18 and 1.66, respectively; TC: t=0.11, 0.59 and 0.62, respectively; all P>0.05). The GSH contentin liver of rats in high dose group was (1 185.82+ 204.01) mg/g, which was significantly different from that in model group at week 12 (735.29 + 35.08) (t=4.97, P 0.05). Conclusions CD diet in SD rats could induce hepatic lipid deposition in liver, and cause liver antioxidative system disorders, GSH exhaustion, and decreases of SOD and GPx activities.Curcumin treatment could improve liver NAS score of NASH rats, and might play a protective role by upregulating the SOD activity and increasing liver GSH content. But curcumin has no effects on liver GPx activity and fat deposition in liver of NASH rats. Key words: Curcumin; Non-alcoholic fatty liver disease; Oxidative stress; Rats