Effect Of Emodin On NETs In Severe Acute Pancreatitis

Objective:To further clarify the existence and role of Neutrophil Extracellular Traps(NETs)in severe acute pancreatitis by establishing a rat model of severe acute pancreatitis.By observing the effects of emodin on neural network,vascular permeability and inflammatory factor TNFalpha in SAP rat model,we discussed the possible targets of emodin for SAP treatment.Methods: According to 18 rats in each group,54 male rats were randomly divided into sham group(Shamgroup),severe acute pancreatitis model group(SAP group),emodin treatment group(Emodin group).After laparotomy,SAP group and Emodin group were established severe acute pancreatitis model by retrograde injecting 5% sodium taurocholate into pancreaticobiliary duct.Sham group rats were not retrograde injecting 5% sodium taurocholate into pancreaticobiliary duct after laparotomy.Emodin group rats were intraperitoneally injected with emodin 0.3ml/100 g after the model establishment 3 hours.Then the other two groups were injected with the same amount of saline.Eight rats were randomly selected from each group at 22 hours after operation and Evans blue solution was injected into tail vein.2 hours later,Evans blue content in pancreatic tissue was measured to reflect changes in vascular permeability.The general condition and gross morphology of the remaining 10 rats in each group were observed at 24 hours after operation.Meanwhile,blood and specimens were collected.Detection of amylase and lipase in blood by automatic biochemical analyzer.HE staining was used to observe the degree of pathological damage of pancreatic tissue.The changes of CitH3 and TNF-? in plasma were detected by enzyme-linked immunosorbent assay.Part of the pancreas was frozen for immunofluorescence detection of CitH3 and MPO,and part of the pancreas was frozen for Western blot detection of CitH3.Results: By observing the general state of three groups of rats,we found that SAP group was obviously the worst,Emodin group was worse than Sham group but better than SAP group.Compared with SAP group,the general condition and morphology of rats in Emodin group were improved;compared with Sham group,the levels of plasma amylase and lipase in SAP group and Emdin group increased significantly(P < 0.05).Compared with SAP group,plasma amylase and lipase in emodin group decreased significantly.(P < 0.05);compared with Sham group,pancreatic tissue HE pathological sections of the rats in the Emodin and SAP group were significantlyincreased(P<0.05).Pancreatic HE staining in Emodin group decreased significantly compared with SAP group(P<0.05);compared with Sham group,the plasma levels of CitH3 and TNF-? in SAP group and Emodin group increased significantly(P<0.05),while the plasma levels of CitH3 and TNF-? in Emodin group decreased significantly(P<0.05);compared with Sham group,the content of Evans blue in pancreas of SAP group and Emodin group increased significantly(P<0.05).The content of Evans blue in pancreas of rats in Emodin group was lower than that in SAP group(P<0.05);immunofluorescence analysis showed that the expression of CitH3 and MPO were hardly observed in the pancreas of rats in Sham group but CitH3 and MPO were significantly increased in SAP group.compared with SAP group,CitH3 and MPO were decreased in Emodin group;western blot analysis showed that a small amount of CitH3 was expressed in the pancreas tissue of rats in Sham group,while the expression of CitH3 in the pancreas tissue of rats in SAP group was significantly increased.The expression of CitH3 in pancreas tissue of rats in Emodin group was lower than that in SAP group(P<0.05).Conclusions:(1)When severe acute pancreatitis occurs,a large number of extracellular traps of neutrophils(NETs)are generated in pancreatic tissue and vivo.(2)Emodin could reduce the production of NETs in rats with severe acute pancreatitis.(3)After emodin inhibited NETs production,the degree of pancreatic microcirculation disturbance and inflammatory reaction improved,then the severity of SAP decreased.