The Protective Function of Erzhiwan on D-galactose-Induced Senescence in Normal Rat Kidney Cells

OBJECTIVE To investigate the protective function of Erzhiwan on Normal Rat Kidney (NRK) cells senescence induced by D-galactose (D-gal). METHODS Different concentrations of D-gal (1， 5， 10， 20， 40 g/L) were added into the culture medium for different processing time (24， 48， 72 h) to induce NRK cells senescence. Cellular senescence was described by senescence-associated β-galactosidase staining and cell viability was evaluated by MTT assay. Fluorescein di-β-D-galactopyranoside (FDG) method was used to detect the quantity of β-galactosidase. The levels of SOD， MDA and GSH-PX in the supernatant were measured to show the changes of oxidative stress. The establishment of the NRK cell aging model was determined according to the outcome of these detections. After that， different concentrations of Erzhiwan (0.01， 0.1， 1 g/L) were added into the culture medium， and the effect of Erzhiwan on the aged NRK cell was observed according to the outcome of FDG detection. The activity of SOD and GSH-PX， the content of MDA were measured. RESULTS Compared with control group， the number of β-galactosidase-positive cells in model group (20 g/L D-gal exposure for 48 h) was apparently increased. In model group， the activity of β-galactosidase detected by FDG was markedly increased， and the activity of SOD， GSH-PX was down-regulated while the content of MDA in the cell culture supernatant was increased. No significant change of the cell viability between the 2 groups was observed. Compared with model group， the activity of β-galactosidase in Erzhiwan treatment group was decreased. Erzhiwan also up-regulated the activity of SOD， GSH-PX and decreased the content of MDA in the cells. CONCLUSION Up-regulation of oxidative stress level exists in D-gal-induced aged NRK cells. Erzhiwan attenuates D-gal-induced senescence in NRK cells.