Protective Effect And Mechanism Of Uncaria On Cerebral Cortex Of Spontaneously Hypertensive Rats

Objective:To study the protective effects of rhynchophylline on cerebral cortex of spontaneously hypertensive rats,and discuss its mechanism.Methods:Form 32 male rats with essential hypertension,were randomly divided into model group,rhynchophylline high dose group,rhynchophylline low dose group,positive control group captopril,8 rats in each group.Another 8 male WKY rats were used as normal control group.After adaptive feeding,normal control group and model were given distlled water(5 ml/kg/d),each treatment group were orally given high dose of rhynchopylline(10 ml/kg/d)?rhynchopylline low dose(2.5 ml/kg/d)?captopril(17.5 ml/kg/d).Intragastric administration at 5 p.m,once a day,continuous administration for 10 weeks.Blood pressure was measured every two weeks using the tail cuff method,after last administration,fasting for 12 hours,rats were killed,whole brain specimen.Determination of superoxide dismutase in cerebral cortex by WST-8(SOD)?Total antioxidant capacity(T-AOC)and hydrogen peroxide(H2O2)content;Determination of malondialdehyde(MDA)in cerebral cortex by thiobarbituric acid colorimetric method;Determination of nitric oxide(NO)in cerebral cortex by nitrate reductase;Nissl staining method was used to observe the pathological changes of cortical neurons;Immunohistochemical technique was used to detect the expression of n NOS and NF-?B positive cells in the cerebral cortex;The expression levels of p22?p47,Bax and Bcl-2 in the cortex of rats were detected by Western Blot(western blot).Results:? Compard with the normal control group WKY,the content of MDA in the cortex of model SHR group increased significantly(P<0.01);Compared with the SHR model group,high dose group,decreased rhynchoplline rhy low dose goup and captopril group have different degrees of trend(P<0.05 or P<0.01);? Compard with the normal control group WKY,the content of SOD in the cortex of model group SHR was significantly decreased(P<0.01);Compared with the SHR model group,high dose group,rised rhynchoplline rhy low dose goup and captopril group have different degrees of trend(P<0.05 or P<0.01);? Compard with the normal control group WKY,the content of NO in the cortex of model SHR group increased significantly(P<0.01);Compared with the SHR model group,high dose group,decreased rhynchoplline rhy low dose goup and captopril group have different degrees of trend(P<0.05 or P<0.01);? Compard with the normal control group WKY,the content of T-AOC in the cortex of model group SHR was significantly decreased(P<0.01);Compared with the SHR model group,high dose group,rised rhynchoplline rhy low dose goup and captopril group have different degrees of trend(P<0.05 or P<0.01);? Compard with the normal control group WKY,the content of H2O2 in the cortex of model SHR group increased significantly(P<0.01);Compared with the SHR model group,high dose group,decreased rhynchoplline rhy low dose goup and captopril group have different degrees of trend(P<0.05 or P<0.01);? Compard with the normal control group WKY, the arrangement of pyramidal cells in the cortex of model group SHR was irregual,and the appearance of cell vacuoles,the phenomenon of empty or light staining of cells,the number of cells decreased significantly light staining of cells(P<0.05);Compared with the SHR model group,high dose group,decreased rhynchoplline rhy low dose goup and captopril group were empty or light staining of cells have eased to some extent,and neuronal cells arranged regularly,its cells structure is also more compact;? Compard with the normal control group WKY,the expression of n NOS positive neurous in cerebral cortex of model group SHR was significantly increased;Compared with the SHR model group,drop of rhynchoplline in high dose group?low dose group and rhynchoppline expressed positive neurons positive control group n NOS of different degrees of trend(P<0.01);? Compard with the normal control group WKY,the expression of NF-?B positive neurous in cerebral cortex of model group SHR was significantly increased;Compared with the SHR model group,drop of rhynchoplline in high dose group?low dose group and rhynchoppline expressed positive neurons positive control group NF-?B of different degrees of trend(P<0.01);? Compard with the normal control group WKY,the expression of p22 protein in the cerebral cortex of model group SHR was significantly increased(P<0.01);Compared with the SHR model group,high dose group?low dose group and positive control group p22 protein have different content degrees of decline(P<0.01);? Compard with the normal control group WKY,the expression of p47 protein in the cerebral cortex of model group SHR was significantly increased(P<0.01);Compared with the SHR model group,high dose group?low dose group and positive control group p47 protein have different content degrees of decline(P<0.01);? Compard with the normal control group WKY,the expression of bax protein in the cerebral cortex of model group SHR was significantly increased(P<0.01);Compared with the SHR model group,high dose group?low dose group and positive control group Bax protein have different content degrees of decline(P<0.01);? Compard with the normal control group WKY,the expression of Bcl-2 protein in the cerebral cortex of model group SHR was significantly decreased(P<0.01);Compared with the SHR model group,high dose group?low dose group and positive control group Bcl-2 protein have different content increased of decline(P<0.01).Conclusion:Rhynchoplline can lower blood pressure in SHR rats,improve the damage of cerebral cortex,the mechanism may increase the content of SOD and T-AOC in the cerebral cortex,reduce the contents of MDA,NO and H2O2 in the cerebral cortex,to decrease the expression of n NOS and NF-Kapp B cells in the cerebral cortex,down regulation of protein content of p22,p47 and Bax,up regulation of Bcl-2 protein,it can protect the cortex of SHR.