Research On The Protective Effect And Mechanism Of Puerarin On Intestinal Ischemia-reperfusion Injury

Intestinal ischemia/reperfusion (I/R) injury is a serious medical problem often necessitating surgical intervention. This study investigated the influences of intestinal ischemia-reperfusion on the gut mucosa antioxidative system and liver, renal function, and pretreatment puerarin in rats subjected to 45 min ischemia with 2 h or 8 h reperfusion, observing the protective effects of puerarin and investigating its action mechanism.The intestinal ischemia-reperfusion was induced in rats by clamping superior mesenteric artery for 45 min followed by reperfusion. The levels of malondialdehyde(MDA), glutathione (GSH) , the activities of antioxidant enzymes in the gut mucosa including catalase(CAT), superoxide dismutase(SOD) and glutathione peroxidase(GSH-Px) and serum alanine aminotransferase(ALT), aspartate aminotransferase(AST), blood urean nitrogen(BUN), creatinine (Cr) were assayed at 2,4,8,12,24 h after reperfusion. The pathological changes of intestine were examined. After using puerarin, intestinal impairment was evaluated via histological examination. The serum nitric oxide (NO) concentration, MDA, GSH levels, myeloperoxidase(MPO) activity, inducible nitric oxide synthase (iNOS) activity and iNOS gene expression in the gut mucosa were measured. Cell apoptosis was defined by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL). The expression of caspase-3 in endothelial cell was detected by immunohistochemical method.The levels of MDA and GSH in the gut mucosa increased and decreased significantly at 2 h of reperfusion, respectively (P<0.05). MDA was still lower than sham at 24 h of reperfusion (P<0.05), while GSH decreased to 40% of sham at 4 h of reperfusion (P<0.01) but returned to the level of control at 12 h. The activities of CAT, SOD and GSH-Px did not show significant changes in rat after intestinal ischemia-reperfusion. Serum ALT, AST, BUN and Cr increased significantly at 2 h of reperfusion (P<0.05) and increased 208%, 100%, 103%, 41% compared with control at 4 h of reperfusion (P<0.01). However, at 24 h ofreperfusion they returned to normal.Puerarin pretreatment can alleviated the mucosal histological disruption caused by intestinal ischemia-reperfusion injury, Puerarin pretreatment did not affect s Cr, but can decrease s ALT, s AST and s BUN levels. Increased GSH and decreased MDA levels were shown in Puerarin low-treated (P<0.05, /><0.01) and high-treated groups (PO.05, P<0.05). In IR group, the gut mucosal MPO activity increased significantly (/><().05). Compared to IR group, significant decreased MPO activity was observed in puerarin high-treated group at 2 h of reperfusion. It was shown that iNOS gene expression increased significantly at 2 h of reperfusion, while serum NO concentration , mucosal iNOS activity increased significantly during 8 h of reperfusion, in contrast, mucosal iNOS gene expression decreased significantly in puerarin high-treated group (P<0.0l, P