ABSTRACT
OBJECTIVE@#To investigate apoptotic effects of berberine, a significant alkaloids component existing in Rhizoma coptidis, and its possible acting mechanism in insulinoma cells.@*METHODS@#Different concentrations of berberine were used to treat mouse insulinoma (MIN6) cells for various period of time. The viability and apoptosis of the cells were analyzed using methylthiazolyldiphenvl-tetrazolium bromide assay, flow cytometry and enzyme-linked immuno sorbent assay. Changes in the relating pro- and anti-apoptosis proteins were detected by western-blotting.@*RESULTS@#The half-maximal inhibitory concentration (IC) of berberine was 5.7 μmol/L on MIN6 cells viability for 16 h. Berberine caused a 20% reduction (P<0.05) in cell number after only 4-h incubation; which reached 50% after 24 h (P<0.01). Berberine treatment for 16 h significantly increased the level of DNA fragmentation. The flow cytometry showed the apoptotic rate increased 2.9- and 4.6-fold after treating with berberine (5 μmol/L) for 8 and 16 h, while 3- and 8.7-fold after 10 μmol/L treatment for 8 and 16 h (P<0.01). Berberine treatment dramatically elevated the expression ratio of Bax to Bcl-2. Meanwhile, berberine notably increased the apoptosis-inducing factors and cytochrome C transforming from the mitochondria to the cytoplasm. Apoptotic protease-activating factor 1 (Apaf-1) was subsequently activated after cytochrome C release. Furthermore, caspase-3 and poly adenosine diphosphate-ribose polymerase were also activated to trigger apoptosis cascade.@*CONCLUSION@#High concentration (5 and 10 μmol/L) of berberine could induce the apoptosis of MIN6 cells through cytochrome C/Apaf-1/caspase-3 and apoptosis inducing factor (AIF) pathway.
ABSTRACT
Objective To study the protective effect of the sodium selenite and benazepril on renal interstitial fibro-sis(RIF) in rat model of unilateral ureteral obstruction(UUO) and its mechanism. Methods The male SD of clean grade rats were randomly divided into sham-operation group,UUO group(UUO model was established by li-gating unilateral ureter), UUO+ sodium selenite group group(sodium selenite 0.2 mg/kg·d gavage), UUO+benazepril group(benazepril 10 mg/kg·d gavage),with 18 in each group.At day 7,14 and 21 after thetreatment, 6 rats selected randomly from each group were killed.The extent of RIF was evaluated by HE and Masson staining of the renal tissue. The expression of connective tissue growth factor(CTGF),transforming growth factor-β1(TGF-β1), alpha smooth muscle actin(α-SMA) andⅢ collagen(ColⅢ) were detected by immunohistochemical method.The protein expression of CTGF and TGF-β1 were detected by Western blot. Chemical colorimetric method was used to detecte the contents of supper oxide dismutase (SOD),malondialdehyde (MDA) and glutathione peroxidase (GSH-px) in renal cortex. Results The extent of RIF and the expression of CTGF,TGF-β1,α-SMA and ColⅢin renal cortex were significantly lower in sodium selenite group and benazepril group at day 7,14 and 21 after the op-eration compared with that in UUO group(P<0.05 or P<0.01). In sodium selenite group and benazepril group,the contents of SOD and GSH-px in renal cortex were higher significantly than those in UUO group at day 7,14 and 21 after the operation respectively(P<0.05),but the MDA in renal cortex was significantly decreased(P<0.05).There were no significant differences in the indexes between the two groups of sodium selenite and benazepril. The expres-sion of CTGF,TGF-β1,α-SMA,ColⅢand the extent of RIF were positively correlated to the level of MDA in UUO group(P<0.05,respectively),and negatively correlated to the level of SOD and GSH-Px(P<0.05,respectively). The expression of CTGF was positively correlated to the expression of α-SMA and ColⅢin UUO group(P<0.05).The expres-sion of CTGF,α-SMA and ColⅢwere positively correlated to RIF in UUO group(P<0.05).Conclusions Sodium sele-nite and benazepril can reduce the extent of RIF in rat model with unilateral ureteral obstruction.