Effects of interlukin-10 on lipopolysaccharide-induced liver injury in rats

Objective To investigate the effects of interlukin-10 (IL-10) on lipopolysaccharide (LPS)-induced liver injury in rats.Methods One hundred male Wistar rats,aged 10-14 weeks,weighing 250-300 g,were randomly divided into 5 groups (n =20 each):control group (C group),LPS group,IL-10 group,HO-1 inducer cobalt protoporphyrin-Ⅸ group (Co group) and HO-1 inhibitor zinc protoporphyrin-Ⅸ group (Zn group).The animals in LPS,IL-10,Co and Zn groups received intraperitoneal LPS 20 mg/kg.IL-10,Co and Zn groups received recombinant human IL-10 1 μg at 3 h before LPS injection.Co and Zn groups received cobalt protoporphyrin-Ⅸ and zinc protoporphyrin-Ⅸ 25 mg/kg at 2 h before administration of recombinant human IL-10.Ten rats in each group were chosen at 24 h after LPS injection and blood samples were collected from the heart for determination of the levels of serum alanine aminotransferase (ALT),aspartate transaminase (AST),tumor necrosis factor-α (TNF-α) and interlukin-1β (IL-1 β).The animals were then sacrificed and lungs removed for determination of glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) activities,malonodialdehyde (MDA) content and expression of HO-1 mRNA in lung tissues.The left 10 rats in each group were chosen and the survival rates within 72 h after LPS administration were recorded.Results Compared with C group,the levels of serum ALT,AST,TNF-αand IL-1 β and MDA content in lung tissues were significantly increased,and GSH-Px and SOD activities in lung tissues and survival rates were decreased in LPS,IL-10,Co and Zn groups (P ＜ 0.05).Compared with LPS group,the levels of serum ALT,AST,TNF-α,IL-1β and MDA content in lung tissues were significantly decreased,GSH-Px and SOD activities in lung tissues and survival rates were increased,and the expression of HO-1 mRNA was up-regulated (P ＜ 0.05).Compared with IL-10 group,the levels of serum ALT,AST,TNF-α and IL-1β and MDA content in lung tissues were significantly increased,and GSH-Px and SOD activities in lung tissues and survival rates were decreased in group Zn (P ＜ 0.05),and no significant change in the parameters mentioned above was found in Co group (P ＞ 0.05).Conclusion IL-10 can attenuate LPS-induced liver injury in rats by inducing the expression of HO-1. Key words: Interlukin-10 ;  Endotoxemia;  Liver