Role of Vitamin C on methotrexate-induced nephrotoxicity in psoriasis context: A preclinical assessment

Methotrexate (MTX) is the most prescribed drug for systemic treatment of psoriasis. However, its clinical use is limited by its nephrotoxicity, which antioxidants can attenuate. This study evaluates the impact of vitamin C (vitC), a well-known antioxidant, on nephrotoxicity induced by high MTX doses in the context of psoriasis. To achieve this purpose, the kidney injury triggered by acute MTX exposure was established in an imiquimod-induced psoriasis-like mouse model. Mice were randomly divided into six groups: group 1 (control); group 2 (Imiquimod, IMQ), group 3 (IMQ+vitC 175 mg/kg/day); group 4 (MTX 20 mg/kg i.p); group 5 (IMQ+MTX 20 mg/kg) and group 6 (IMQ+MTX 20 mg/kg + vitC 175 mg/kg/day). The effects of these treatments were determined by considering the evolution of IMQ-induced skin lesions and serum creatinine levels. Moreover, histopathological analysis, lipid peroxidation, oxidative stress, and TNF-α production were determined in kidney tissue. Results showed that vitC attenuates renal damage in the context of IMQ-induced psoriasis. However, the opposite occurs when administered with IMQ+MTX, worsening skin psoriasis lesions and exacerbating acute renal tubular necrosis and oxidative DNA damage. These results establish new clues about the MTX-induced nephrotoxicity in the psoriasis context and the putative protective effects of vitC. It suggests that vitC supplementation could help attenuate the renal damage promoted by the psoriatic pathological environment. However, it should be avoided in psoriasis patients with renal dysfunction treated with MTX.