The nephroprotective effect of Quercetin in Cyclophosphamide-induced renal toxicity might be associated with MAPK/ERK and NF-κB signal modulation activity.

The present study aimed to examine the protective effect of quercetin (QUE) on cyclophosphamide (CTX)-induced nephrotoxicity. For that purpose, 24 mice were divided into four groups (Control, QUE, CTX, and CTX + QUE). The CTX and CTX + QUE groups received 200 mg/kg of cyclophosphamide on the 1^st and 7^th days. The QUE and CTX + QUE groups were treated with 50 mg/kg of quercetin daily for 14 days. At the end of the experiment, the animals were sacrificed, and kidney samples were analyzed. The results indicated that CTX leads to severe morphological degenerations and disruption in renal function. Serum BUN, Creatinine, Uric acid, tissue Bax, Caspase 3, TNF-α and IL-1β expression levels were upregulated in the CTX group compared to Control and QUE groups (p < 0.05). Although MAPK/ERK phosphorylation level is not affected in CTX group, there was a significant increase in CTX + QUE group (p < 0.05), but the NF-κB was significantly suppressed in this group (p < 0.01). The RT-qPCR results showed that the cyt-c and the Bax/Bcl-2 ratio mRNA expression folds were upregulated in the CTX group (p < 0.01), which was downregulated in the CTX + QUE group. However, there was a significant difference in the CTX + QUE group compared to the Control and QUE groups (p < 0.01). The findings showed that administering quercetin along with cyclophosphamide alleviated renal injury by regulating apoptotic and inflammatory expression. Moreover, the administration of quercetin and cyclophosphamide could synergistically improve renal function test results, and activate cellular responses, which upmodulate MAPK/ERK phosphorylation and suppression of NF-κB.