Effects And Mechanism Of Rhubarb On Intestinal Mucosal Barrier In Experimental Rats With Acute Intrahepatic Cholestasis

Objective: To explore the effects and mechanism of rhubarb on intestinal mucosal barrier in experimental rats with acute intrahepatic cholestasis induced by alpha- naphthylisothiocyanate(ANIT).Methods: Seventy young male SD rats were randomly assigned into control group (10), model group(30) and rhubarb treated group(30). Model group and rhubarb treated group received a single intragastric administration of alpha-naphthylisothiocyanate(ANIT,50mg/kg)in order to induce acute intrahepatic cholestasis. Rhubarb (4ml/kg, bid) was given to rhubarb treated group 3 days before ANIT was administrated until executed. At 24 h, 48 h and 72 h after modeling, every 10 rats in each group were executed for taking terminal ileum tissue and abdominal aortal blood. Serum total bilirubin(TB) and alanine aminotransferase(ALT)were assayed and the pathological changes of terminal ileum tissue was observed by light and electron microscopy. Immunohistochemistry and Western blot techniques were used to examine the distribution and expression of ZO-1, Occludin, NF- -κB and TNF-α. SPSS 13.0 software was used to analyze the data.Results: 1. Comparing with control group, the levels of serum ALT and TB in the model group and rhubarb treated group increased obviously(P<0.05), reached the pinnacle by 48h. But the alteration of the rhubarb treated group were decreased significantly than those of the model group(p﹤0.05).2. In the control group, complete intestinal villus structure was observed by light and electron microscopy. In the model group, sparse intestinal villi and structural damage were observed. In the rhubarb treated group, pathological changes of intestinal mucosa were reduced than model group.3. Western blot demonstrated consistent with immunohistochemistry. ZO-1 and Occludin in model group and rhubarb treated group decreased at 24h, decreased most obviously at 48h, and partly recovered at 72h, which were significantly lower than that in control group(P<0.05). TNF-αand NF- -κB in model group and rhubarb treated group increased at 24 hour, increased most obviously at 48 h, and partly recovered at 72 h, which were significantly higher than that in control group(P<0.01). Compare with model group, ZO-1 and Occludin in rhubarb treated group increased obviously at 24h, 48h and 72h (P<0.05), TNF-αand NF-κB in rhubarb treated group decreased obviously at 24h, 48h and 72h (P<0.05).Conclusion: Rhubarb can increase distribution and expression of epithelium tight junction proteins and decrease distribution and expression of inflammatory cytokines. So Rhubarb can recover the integrity of intestinal mucosal barrier in experimental rats with acute intrahepatic cholestasis.