Hepatoprotective Effect of Chitosan Oligosaccharides on CCl4-induced Liver Injury in Rats

Various toxic materials cause hepatocellular injury and finally hepatic fibrosis or cirrhosis. It is well known that development of hepatic fibrosis is mediated by hepatic stellate cells (HSCs) and transforming growth factor-betas (TGF-ss) signalling mechanism. The aim of this study is to demonstrate hepatoprotective effect of chitosan oligosaccharides (COS) using carbon tetrachloride (CCl4) intoxicated rat model. For this study, three groups of animals were prepared. Group A was given corn oil only, but group B and C were given CCl4 once a week for 4 weeks. And group C was additively given COS daily for 4 weeks. After then, serological, histological, and western blot analyses were performed. COS treatment prevented increment of liver weight and elevation of serum ALT level. It also reduced hepatocellular damages and prevented development of hepatic fibrosis and collagen deposit. The immunohistochemistry and western blot analysis showed that COS treatment decreased activation of HSCs and expression of type I TGF-s receptor. These results suggest that COS effectively protects liver from CCl4-induced hepatocellular injuries and hepatic fibrosis.