Nephroprotective Potential of 1,3,4‐Oxadiazole Derivative Against Methotrexate‐Induced Nephrotoxicity in Rats by Upregulating Nrf2 and Downregulating NF‐κB and TNF‐α Signaling Pathways

Nephrotoxicity is a prominent complication of methotrexate (MTX) therapy that limits clinicians in its extensive use. MTX triggers oxidative burden and inflammation, so the nephroprotective potential of the synthetic derivative of 1,3,4-oxadiazole (5b) was explored in this research. Male Wistar rats were divided into four groups i.e., control group, MTX group, 5b (5 mg/kg) + MTX group and 5b (10 mg/kg) + MTX group, respectively. All treatments were given, intraperitoneally (i.p.) during 12 days of the animal model. The MTX-induced nephrotoxicity was evaluated by renal function markers i.e., serum creatinine (Cret), blood urea nitrogen (BUN), and albumin (Alb). Furthermore, antioxidant markers, catalase (CAT), glutathione-S-transferase (GST), and reduced glutathione (GSH), and oxidative stress, markers lipid peroxidase (LPO) and nitric oxide (NO), were analyzed. Pro-inflammatory cytokines, interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α), were also calculated. DNA damage was assessed by the comet assay. Histopathological staining (Hematoxylin and eosin, Masson's trichrome) was done and immunohistochemistry was performed against Caspase-3, Nrf2, HO-1, TLR-4, TNF-α, and NF-κB. A significant improvement in the serum Cret, BUN, and Alb was observed in (5b) treated groups. Antioxidant markers were elevated, oxidative stress markers and pro-inflammatory cytokines were reduced, moreover, histopathological analysis revealed less tissue damage in (5b) administered groups. Immunohistochemistry showed increased immune expression of Nrf2 and HO-1 and decreased expression of TLR-4, TNF-α, Caspase-3, and NF-κB in 5b (5 mg/kg) + MTX group and 5b (10 mg/kg) + MTX group as compared to the MTX group. Hence, the results of this study favor the use of (5b) against MTX-induced nephrotoxicity.