L-carnitine exerts a cytoprotective effect against H₂O₂-induced oxidative stress in the<i>fathead minnow</i>muscle cell line

Abstract

This study was conducted to investigate the protective effect of L-carnitine (LC) against H 2 O 2induced oxidative stress in the fathead minnow muscle cell line (FHM). The FHM cells were stimulated with 1 mM H 2 O 2 for 1 h after LC pre-treatment, and the cell viability and the activity and mRNA relative expression of antioxidant enzyme were measured to assess the antioxidant properties of LC. The results showed that the toxic effect of H 2 O 2 on the viability of FHM cells was both dose-and time-dependent. Furthermore, the viability of the 0.01-1 LC mM groups was significantly higher than those of the 1 mM H 2 O 2 group. L-carnitine protected the cells from H 2 O 2 -induced oxidative damage, which was demonstrated by a significant reduction in the malondialdehyde and reactive oxygen species levels and increases in the intracellular total glutathione levels and the activities of total superoxide dismutase, catalase, glutathione peroxidase (GPx) and gamma-glutamyl-cysteine synthetase (c-GCS) in FHM cells pre-treated with LC for 6 h compared with the 1 mM H 2 O 2 group. In addition, the mRNA relative expression levels of the c-GCS catalytic subunit and nuclear factor nuclear factor erythroid 2-related factor 2 were significantly higher than those of the 1 mM H 2 O 2 group. It could be concluded that LC exerts a beneficial antioxidant effect against oxidative stress induced by H 2 O 2 in FHM cells and that the appropriate treatment is 0.1-1 mM for 6 h in this study.