Effects of Ginkgo biloba extract on the expression of apoptosis-controlling genes in renal tubular cells during ischemia-reperfusion injury in rat kidney

Objective To study the effects of Ginkgo biloba extract(EGb) on the expression of Bcl-2 and Bax genes during renal ischemia-reperfusion(I/R) in rats.Methods The model of bilateral post-ischemic renal injury was set up by clamping renal pedicles for 45 minutes and allowing reperfusion for 24 hours.After that,the apoptosis of tubular cells was assessed by terminal-deoxynucleotidyl transferase mediated d-UTP nick end labeling(TUNEL) method,the expression of Bcl-2 and Bax was examined by immunohistochemistry.Results Compared with the results of sham operation group,significant increase of TUNEL positive cells,higher expression of Bax and Bcl-2,and increased Bax/Bcl-2 ratio were observed in I/R group(P0.01).The EGb pretreatment group showed a significantly lower number of apoptotic positive nuclei than the I/R group(P0.01),along with increased expression of Bcl-2,decreased expression of Bax and decreased Bax/Bcl-2 ratio.Conclusion Inhibition of apoptosis and regulation of Bcl-2/Bax expression may be responsible for the renal protective effects of EGb in the rats undergoing renal ischemia-reperfusion.