Protective Effect of Salvia Przewalskii Extract on Puromycin-Induced Podocyte Injury

Abstract

Background: To determine the effect of Salvia przewalskii extract (SPE) from total phenolic acids on puromycin aminonucleoside (PAN)-induced rat podocyte injury. Methods: The rats were divided into groups that were treated with either PAN only or PAN followed by tacrolimus or SPE. We evaluated the effects of SPE on podocyte injury 5, 10, 15 and 21 days following treatment. Results: (1) Proteinuria was observed starting on day 5 in all groups. The peak levels of proteinuria differed among the groups with tacrolimus and high-dose SPE, which significantly decreased proteinuria relative to the PAN and low- and medium-dose SPE groups. The proteinuria in each group decreased by day 15 and returned to a normal level by day 21. (2) H&E and PAS staining revealed no abnormality in glomerular morphology. With electron microscopy, we observed foot process effacement in the rats of all groups starting on day 5, but rats in the tacrolimus and high-dose SPE groups exhibited a lower degree. (3) IHC staining of nephrin and podocin revealed unaffected expression and better linear distributions in the high-dose SPE and tacrolimus groups. Western blot analysis confirmed that SPE could improve the expression of proteins. (4) The mRNA levels of nephrin and podocin in the tacrolimus and high-dose SPE groups were significantly higher than that in the others. Conclusion: In our study, we first demonstrated the ability of SPE to reduce proteinuria, preserve the morphology and structure of podocytes and retain the levels of slit diaphragm proteins on PAN-induced rat podocytes injury.