Electron donating and withdrawing groups affect the antioxidant activity of 4′-aminochalcones on gentamicin-induced kidney cell injury

Abstract Gentamicin (GM)-induced nephrotoxicity is closely linked to oxidative stress, with few therapeutic alternatives available. Chalcones are structurally versatile compounds with reported antioxidant properties, making them attractive candidates for nephroprotection. The 4′-aminochalcones substituted with p -NO 2 (31.25–15.62 µM) or p -N(CH3) 2 (7.81 µM) groups demonstrated significant protective effects, partially restoring (∼11 %) HK-2 cell viability after GM-induced injury. Both derivatives increased intracellular glutathione levels, reduced superoxide accumulation, and lowered cytoplasmic ROS concentration. Structural and electronic analyses revealed that the electron-donating group p -N(CH3) 2 enhanced antioxidant reactivity, whereas the electron-withdrawing group p -NO 2 decreased cytotoxicity. HK-2 cells were exposed to GM (IC 50  = 5.0 ± 0.7 mmol/L) for 24 h, followed by treatment with 4′-aminochalcones (250–7.81 µM). Cell viability was assessed by MTT assay. ROS were quantified by flow cytometry using DCFH-DA, while redox balance was evaluated through glutathione content and superoxide accumulation. The electronic properties of chalcone derivatives were further investigated by density functional theory calculations. The 4′-aminochalcones mitigate GM-induced oxidative stress in renal cells, and their antioxidant and cytoprotective activities are strongly influenced by electronic substituents. Electron-donating groups enhance reactivity, whereas electron-withdrawing groups improve safety, underscoring the importance of structure-effect relationships in the design of chalcone-based nephroprotective agents.