Effect of Ursolic Acid on Early Brain Injury after Subarachnoid Hemorrhage and Matrix Metalloproteinase-9 in Rats

OBJECTIVE To explore the effect of ursolic acid(UA) on early brain injury(EBI) after subarachnoid hemorrhage(SAH) and matrix metalloproteinase(MMP)-9. METHODS The SAH model was induced by endovascular puncture. The scores of neurologic impairment were measured after SAH for 24 h. The rats in each group were executed after SAH for 48 h and the contents of water and Evans blue in brain were measured. Gelatin zymography assay was used to measure the activity of MMP-9. Real-time PCR was used to measure the expression of MMP-9 mRNA. Western blot was used to measure the expression of MMP-9 protein. Nissl staining was used to detect the survived neurons in brain. RESULTS Compared with the model control group, the activity and the expression of MMP-9 mRNA and protein signifincantly decreased in ursolic acid groups. UA also relieved the symptoms of nervous function impairment, decreased the contents of water and Evans blue in brain and improved the reduction of neurons in brain after SAH. Compared with the positive control(doxycycline) group, there was no significant difference between doxycycline and UA of the effects on MMP-9. CONCLUSION UA could promote EBI after SAH and its mechanism may be related with inhibition of the expression of MMP-9.