Protective Role of Boldine Against 5‐Fluorouracil‐Induced Nephrotoxicity: In Vitro and In Vivo Approach

Drug-induced nephrotoxicity is a significant clinical complication associated with several chemotherapeutic agents, including 5-fluorouracil (5-FU). This study was aimed to investigate the nephroprotective potential of boldine, an aporphine alkaloid, against 5-FU-induced renal toxicity using in vitro (HEK293 cells) and in vivo (Wistar rats) models. In vitro cytotoxicity was evaluated using the MTT assay, AO/EB and DAPI staining was performed to identify apoptotic alterations. The expression of apoptotic and antioxidant genes was analyzed by quantitative and semi-quantitative PCR. For the in vivo study, rats were divided into five groups. One group received a single intraperitoneal dose of 5-FU (150 mg/kg) to induce nephrotoxicity. In the remaining groups, 5-FU was administered followed by oral treatment with boldine (10 or 20 mg/kg) or silymarin (100 mg/kg) for 7 days. Biochemical markers including creatinine, urea, blood urea nitrogen, uric acid in serum and oxidative stress indicators in kidney tissue were analyzed. MAPK pathway-related gene expression and histopathological changes were assessed. Treatment of HEK cells with 5-FU markedly reduced cell viability and induced apoptosis, while co-treatment with boldine restored viability and normal cell morphology. Boldine modulated the 5-FU-induced downregulation of SOD, CAT, GPx, and Bcl-2 and upregulation of Bax and caspase-3. In vivo, boldine treatment normalized elevated nephrotoxic markers in serum, enhanced antioxidant enzyme activities, and inhibited activation of ASK1, ERK1, c-Jun, and NF-κB1. Histopathological findings further confirmed that boldine preserved renal tissue integrity and prevented tubular and glomerular damage. Overall, boldine significantly protected against 5-FU-induced renal injury via anti-apoptotic, antioxidant, and anti-inflammatory mechanisms.