Effects Of Yunnan Baiyao On The Arachidonic Acid Metabolism Of COX Pathway

[Objective]:The purpose of the study is to research the effects of Yunnan Baiyao (YNB)on arachidonic acid metabolism of COX pathway and explore the mechanism of YNB in anti-inflammatory aspects.[Methods]:96 healthy male SD rats,6-8 week-old,were randomly divided into four groups:normal group(24 rats),model group(24 rats),celecoxib group(24 rats),YNB group(24 rats). After continuous drug intervention for 7days, paw inflammation model was induced by carrageenan.YNB group were intragastrically adiminstered 50mg/ml Yunnan Baiyao,1 times a day;celecoxib group,as positive control group, were intragastrically administered celecoxib 10mg/kg,once a day;the model group and normal group were intragastrically administered lOml/kg physiology saline,once a day.Two hours after intragastric administration at the seventh day, Three model groups were subcutaneously injected 0.15mL carrageenan in the left paw and 0.15mL saline in the right paw as control,the normal group received 0.15mL saline injection in the right and left paw.Respectively measuring paw volume after injected in 1 hour,2 hour,3hour and 4 hour each time point. At the same time,12 rats were randomly taken from each group in 2h and 4h,anesthesia by 10% chloral hydrate, put to death after collecting the blood from the abdominal aorta. inflammation tissues were preserved in 4% poly formaldehyde fixative and RNA preservation solution to observe the inflammatory infiltration by HE staining and the level of COX-2% PGE2% cPLA2 expression by RT-PCR..ELISA was used to detect the level of COX-2、PGE2、TXA2、 cPLA2 in serum.Statistical analysis of the experimental results using SPSS17.0 statistical software.[Results]:1. The change of paw swelling degree in rats :compared with normal group, left paw swelling was obviously higher in the model group,YNBgroup, celecoxib group.With time extended to 3 hours,the swelling reached a peak in the model group. continuous intragastric administration for 7 days before modeling, YNB group and celecoxib group showed effect after 1h of the model.Compared with the model group, rat paw edema volume decreased gradually, but still higher than the normal group.2. the content change of COX-2、PGE2、TXA2、cPLA2 in plasma:the expression of COX-2, PGE2, TXA2, cPLA2,in YNB group and celecoxib group, was significantly lower than that in the model group in 2h and 4h,. With the time prolonged, all indexes in YNB group were decreased.compared with celecoxib group, TXA2 content inYNB group is obviously lower,which has statistical significance.4. COX-2, PGE2, cPLA2 expression results of inflammatory tissue showed that the expression of COX-2, PGE2, cPLA2 in YNB group and celecoxib group was significantly lower than that in the model group in 2h and 4h. With the extension of time, all indexes of YNB group were decreased.5. HE staining:soft tissue of the rats in the normal group were very rare inflammatory cell infiltration, visible dense subcutaneous connective tissue; soft tissue in the model group has a large number of inflammatory cell infiltration, mainly lymphocytes and a few eosinophil and individual neutrophil cells and obvious hyperaemia, oedema, loose connective tissue, tissue gap increases.soft tissue inflammatory cell infiltration,in YNB group and celecoxib group,was significantly reduced.[Conclusion]:1.Prophylactic administration of YNB can inhibit the expression of COX-2/cPLA2 and product of PGE2/TXA2,which were in arachidonic acid metabolism of COX pathway,by which YNB can reduce inflammatory reaction and relieve the inflammatory soft tissue swelling.2. Expression of the COX-2,cPLA2,PGE2 inhibited by YNB is weaker than that of celecoxib, but inhibiting TXA2 protein synthesis is stronger.