Effect of berberine pretreatment on hypoxia/reoxygenation-induced apoptosis in human renal tubular epithelial cells

Objective To investigate the effect of berberine pretreatment on hypoxia/reoxygenation (H/R)-induced apoptosis in human renal tubular epithelial cells.Methods The human renal tubular epithelial cells were cultured and seeded in culture dishes (2 ml/dish) or 96-well plates (200 μl/well) with the density of 1 ×106/ml.The cells were then randomly divided into 4 groups (n =30 each):normal control group (group C),berberine group (group B),H/R group and H/R + berberine group (H/R + B group).In groups B and H/R + B,berberine 10 μmol/L was added to the culture medium and the cells were incubated for 2 h.Groups H/R and H/R + B were then exposed to 94％ N2-5％ CO2-1％ O2 for 24 h followed by 3 h reoxygenation.The cell viability,apoptotic rate and level of malondialdehyde (MDA) and superoxide dismutase (SOD) were detected.The expression of caspase-3,activated caspase-3,cytochrome c,glucose-regulated protein 78 (GRP78) and C/EBP homologous protein (CHOP) was determined.The ratio of Bax/Bcl-2 was calculated.Results Compared with group C,the cell viability,SOD activity and caspase-3 expression were significantly decreased,the apoptotic rate,Bax/Bcl-2 ratio and concentration of MDA were increased,and the expression of activated caspase-3,cytochrome c,GRP78 and CHOP was up-regulated in groups H/R and H/R + B (P ＜ 0.05).Compared with group H/R,the cell viability,SOD activity and caspase-3 expression were significantly increased,the apoptotic rate,Bax/Bcl-2 ratio and concentration of MDA were decreased,and the expression of activated caspase-3,cytochrome c,GRP78 and CHOP was down-regulated in group H/R + B (P ＜ 0.05).Conclusion Berberine pretreatment can inhibit H/R-induced apoptosis in human renal tubular epithelial cells,and inhibition of mitochondrial stress pathway and endoplasmic reticulum stress pathway is involved in the mechanism. Key words: Berberine;  Apoptosis;  Oxygen;  Cell hypoxia;  Epithelial cells;  Kidney tubules