ABSTRACT
Aim To investigate the effects of Ginkgo biloba extract(EGB)on tumor necrosis factor-alpha(TNF-?)in TNBS-induced colitis in rats and its mechanisms.Methods Colitis in rats was induced by colonic administration with 2,4,6-trinitrobenzene sulfonic acid(TNBS).Wistar rats were randomly divided into four groups,10 in each:normal group,model group,5-aminosalicylic acid(5-ASA group)and Ginkgo biloba extract group(EGB group).The levels of nitric oxide(NO),and glutathion peroxide(GSH-Px)were measured by biochemical methods.The expressions of TNF-? and nuclear factor kappaBp65(NF-?Bp65)in the colon tissues of colitis rats were detected by means of immunohistochemistry.The expressions of induce nitric oxide synthase(iNOS)in the colon tissues of colitis rats were detected by reverse transcription polymerase chain reaction(RT-PCR).The effects of EGB on colonic inflammation and macroscopic and histological damage were evaluated as well.Results Compared with the model group,treatment with EGB for 4 weeks significantly reduced colon macroscopic and histological damage,elevated the activities of GSH-Px and reduced the contents of NO,inhibited the protein expressions of TNF-? andNF-?Bp65,and decreased the mRNA levels of iNOS in the colon tissues of experimental colitis.Conclusions The probable mechanisms of EGB was that it ameliorated inflammatory injury in TNBS-induced colitis in rats by its reduction of TNF-?,NF-?Bp65 and iNOS levels.Then EGB could curb the inflammatory cascade effects of inflammatory mediators to protect ulcerative colitis.