Objective To investigate the effect and the potential mechanism of TXL on aortic biological variation and plasma or tissue factor in Ang Ⅱ induced a deficiency condition of rat contributed to the development of vascular dysfunction.Methods 50 rats were divided into sham group(C),group AngⅡ(A),group both AngⅡ and TXL(T+A).Ang Ⅱ pump were embedded in rat back in group A and T + A,whereas physiological saline pump in group C.Group TXL was given by gastric tube every day.After treatment of 14 days,including AngⅡ,ET,NO,IL-6 and TNF-α in the plasma were examined.The aortic endothelial cell was observed by SEM.NF-κB,VCAM-1 and eNOS expression in aorta were measured by immunohistochemistry assays.Apoptotic cells were tested by TUNEL kit,NAD(P) H oxidase subunit P22phox mRNA was quantified with RT-PCR.Results The plasma concentration of ET,IL-6,TNF-αin group A increased markedly compared to Group C and T + A whereas decreased in group T + A.The same changes about endothelial morphology,NF-κB,VCAM-1,apoptosis and P22phox mRNA expression in aortic tissue increased significantly in aorta among the groups.However eNOS expression in aorta had a reverse response.These changes in group T + A were ameliorated significantly by TXL(P ＜ 0.05).Conclusion The findings suggested a dose-dependent induction of proatherosclerotic oxidative stress in rat in response to Ang Ⅱ.TXL may have an effect of prevention of aortic tissue from injury mediated through a reduction of apoptotic processes and has an improvement effect on the activation of the immune system.TXL has an antiatherosclerotic and antioxidative potential by the reduction of oxidative stress and apoptosis in the vessel wall.