ABSTRACT
Objective To determine the effect of Salvia przewalskii extract of total phenolic acids (SPE) on puromycin aminonucleoside (PAN)-induced oxidative stress in podocytes of rats in vivo and the effect of SPE on PAN-induced oxidative stress in podocytes of mice in vitro. Methods (1) Nephropathy rat model was established by PAN and was given intervention with SPE and tacrolimus. The renal tissue samples were obtained for WT1 staining to calculate the number of podocytes on the 5th# 10th# 15th and 21st day. The intensities of 8-hydroxy-27-deoxyguanine (8-OHdG) were evaluated by immunofluorescence. (2)The podocytes of mice were exposed to PAN for 24 h in vitro#, and then SPE# salvianolic acid B (SalB) # rosmarinic acid (RA) or tacrolimus were added for 6# 12# 24# and 48 h culture. Then the cytoskeleton distribution of podocytes, indicated by F-actin# was observed by fluorescence microscopy, and the intracellular reactive oxygen species (ROS) production was measured by flow cytometry. Results (1) Decrease of podocytes per glomerular volume as measured by counting WT1-positive cells was started on day 5 in each group except normal control (NC) group# and on day 15 glomerular podocytes in PAN group was significantly less than that in the NC group ([14. 4 + 0. 7]/glomerular volume vs [37. 2 + 1. 5]/glomerular volume# P<0. 05). The numbers of glomerular podocytes in SPE group and positive group (tacrolimus group) were more than that in PAN group at all time points. The glomerular podocyte count of high-dose SPE group was similar to that of positive group on day 15 ([21. 7 + 1. 0]/glomerular volume vs [23. 6 + 1. 2]/glomerular volume# P<0. 05). After injection of PAN# 8-OHdG intensities were increased in each group except normal control group on day 5; and the intensities peaked on day 10 and then began to decrease# but still higher than that of the normal control group on day 15. The intensities of 8-OHdG in renal tissue was decreased after intervention# and those of the tacrolimus and high-dose SPE groups were similar. (2) In vitro study found that F-actin of podocytes was almost completely disrupted 24 h after PAN treatment# with disrupted filamentous structure. After the treatment with tacrolimus, SPE, SalB and RA# the PAN induced injury of podocytes was lessened# with reappeared polarity distribution of intracellular microfilaments. Compared with NC group# the ROS production in podocytes was significantly increased in PAN group (P<0. 05). After treatment of podocyte with drugs# the ROS production was decreased. The cellular ROS production of positive control group was similar to those in tacrolimus group, low-dose SPE group, high-dose SalB group and RA group at 24 h. Compared with RA,SalB had a better efficacy in reducing ROS# and the reducing effect had a positive relation with drug dose. Conclusion Our study suggests that SPE can protect podocytes from PAN-induced oxidant stress in vivo and in vitro.