Renoprotective effects of umbelliferone on methotrexate-induced renal injury through regulation of Nrf-2/Keap-1, PMAPK/NF-κB, and apoptosis signaling pathways.

Nephrotoxicity is the major dose-limiting adverse effect of methotrexate (MTX). Umbelliferone (UMB) is a known coumarin derivative. The current study aimed to investigate possible protective effects of UMB against MTX-induced nephrotoxicity. Adult male albino rats were divided into: control group, UMB group (30 mg/kg, p.o), MTX group (single i.p. injection of 20 mg/kg) and MTX + UMB group. Serum urea and creatinine were evaluated. The renoprotective effects of UMB were evaluated by estimation of renal Nrf-2/Keap-1 and PMAPK/NF-κB, GSH, MDA, NO contents and SOD activity. Moreover, expression of Bcl-2, Bax and caspase-3 were determined. The results demonstrated that UMB significantly reduced serum creatinine and urea levels with alleviations of histopathological abrasions induced by MTX. It limited oxidative stress via lowering both renal MDA and NO contents and restoring renal content of reduced GSH and SOD activity with downregulation of Keap-1 and upregulation of Nrf-2. UMB downregulated PMAPK and NF-κB expression levels. In addition, UMB increased Bcl-2 protein expression while decreasing both Bax and caspase-3 expression levels. Importantly, UMB enhanced the cytotoxic activity of MTX human cancer cell lines. In conclusion, UMB possess marked renoprotective effects against MTX-induced renal damage through modulating oxidative stress, inflammation and apoptosis with enhancement of its cytotoxic activity.