Multi-Pathway Renoprotection by Betanin Against Docetaxel Nephrotoxicity: Modulation of Inflammation, ER Stress, Apoptosis, and Ferroptosis

Docetaxel (DTX), a cornerstone chemotherapeutic agent, has its clinical utility significantly limited by dose-dependent nephrotoxicity. This study investigated the multi-pathway renoprotective mechanisms of betanin (BTN), a natural antioxidant derived from beetroot, against DTX-induced kidney injury. Male Wistar rats received DTX (30 mg/kg, i.p., single dose) with or without BTN (100 mg/kg/day, p.o.) for 7 days. DTX induced severe renal dysfunction with elevated serum urea and creatinine, and significant oxidative stress characterized by increased MDA and decreased GSH, GPx, SOD, and CAT. Molecular analysis demonstrated widespread upregulation of pro-inflammatory (NF-κB, TNF-α, IL-1β), endoplasmic reticulum stress (PERK, ATF6), pro-apoptotic (Caspase-3, Bax, Apaf-1), and pro-ferroptotic (PTGS2, TfR1) mediators, with concurrent downregulation of protective Bcl-2 and GPx4. Histopathological examination revealed extensive tubular injury, while immunohistochemical analysis showed markedly increased kidney injury marker KIM-1 and decreased aquaporin-1 expression. Remarkably, BTN co-administration significantly attenuated all biochemical, molecular, and structural derangements, restored tissue architecture, and normalized KIM-1 and AQP-1 expression. In conclusion, betanin provides robust, multi-pathway renoprotection against docetaxel-induced nephrotoxicity by concurrently targeting oxidative stress, inflammation, ER stress, apoptosis, and ferroptosis.