The effects and significances of the expression of the silent information regulator 1 protein under the influence of berberine in cholestatic kidney in rats

Abstract

Objective To determinethe expression of silent information regulator 1(SIRT1), superoxide dismutase(SOD), malondialdehyde(MDA)and the glutathione(GSH), the aim of this study is to investigate the effects of the berberine to the expression of the SIRT1 protein and the protective effects to the renal function as related to cholestatic kidney injury in rats. Methods The animals were divided randomly into three groupls(n= 15).A rat model of cholestasis was established by bile duct ligation(BDL, B group)and compared with a Sham group receiving laparotomy without BDL(Sham, A group), and with the the BBR given respectively following BDL(BDL+ BBR, C group). All rats were sacrificed on the 7th day after BDL and the blood and kidney tissue samples were obtained.The expression of the SIRT1 proteins were analyzed by western blotting and the reverse transcriptase-polymerase chain reaction(RT-PCR)was performed to determine the mRNA expression of SIRT1 in all groups.The kits of SOD, MDA and GSH were used to detect the values in renal tissue and the apoptosis of the kidney cells was examined by Td T-mediated dUTP nick end labeling(TUNEL)staining. Results After the bile duct ligation, the model of cholestasis was established. Comparedto A group, the levels of the mRNA and proteins of the SIRT1,SOD and GSH were lower but the alanine transaminase(ALT), MDA and the apoptosis rate were higher in group B(P< 0.05). Compared C groups to B group, the levels of the mRNA and proteins of the SIRT1, SOD and GSH were higher but the MDA and the apoptosis rate were lower(P<0.05).The values of BUN,Cr,SOD,GSH,SIRT1 mRNA and protein and the rate of the A,Band C groups are:A group(3.14±0.53)mmol/L,(31.32±11.08)μmol/L, (19.45±2.41)nu/mg,(2.31±0.14)nmol/g,1.00±0.00, 0.27±0.01,(0.28±0.13)%; B group(8.37 ±1.57)mmol/L,(102.43±9.32)μmol/L,(5.96±1.43) nu/mg,(1.39±0.25) nmol/g, 0.51±0.05, 0.17±0.01,(19.36±2.56)%; C group(6.04±1.52) mmol/L,(78.58±13.63)μmol/L,(13.52±1.47) nu/mg,(1.97±0.19)nmol/g,0.79±0.04,0.22±0.01,(11.47±3.61)% the group A,B and C. Conclusion The present study demonstrates that the BBR could protect the kidney from the peroxide damage by increasing the expression of the SIRT1 which could promote the expression of the gene of SOD. And so the BBR plays a benefical role to resist peroxide damage and apoptosis in cholestatickidney injury. Key words: Berberine; Cholestasis; Silent information regulator 1; Superoxide dismutase