Lycopene improves methotrexate-induced functional alterations of the Madin-Darby kidney cells in a concentration-dependent manner.

Lycopene is one of the most potent antioxidants among carotenoids due to its ability to quench singlet oxygen and react with free radicals to reduce DNA damage. Methotrexate is widely used in the treatment of several types of cancers and autoimmune diseases. One of the most common side effects of a high-dose of methotrexate is kidney injury. In this study, we evaluated effects of lycopene on the Madin-Darby canine kidney cells (MDCK) treated with methotrexate through the estimation of their mitochondrial and lysosomal functions ((4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide reduction assay and neutral red uptake assay) and changes in cell oxidative status (determination of advanced oxidized proteins concentrations and reduced glutathione levels) and lysosomal enzymes activity (β--acetyl glucosaminidase activity). Results of our study showed that lycopene applied in high concentration caused significant impairment of the MDCK function leading to cell death. Contrarily, in relatively low concentrations lycopene moderately ameliorated methotrexate-induced MDCK cell death estimated by both biochemical and microscopic analyses. It also prevented a significant decline in the MDCK cell lysosomal function estimated by neutral red accumulation ability and activity of the lysosomal enzyme β--acetyl glucosaminidase.