Protective Effect of L-carnitine on the Oxidative Stress Injury of Human Ovarian Granulosa Cells

Abstract

The protective effect of L-carnitine (LC) on the oxidative stress (OS) injury and the effect of L-carnitine on follicular stimulating hormone receptor (FSHR) of ovarian granulosa cells (GCs) were investigated. OS was induced by treatment with H2O2. We cultured KGN cells in four groups: the blank group, OS group and two L-carnitine pretreatment group (low, high). In the OS group, cell nuclear pyknosis was observed, mitochondria swelled irregularly and their cristae were fractured. Meanwhile, the cell viability, superoxide dismutase (SOD) and glutathione (GSH) contents, mitochondrial membrane potential (ΔΨm) and the level of FSHR expression were significantly decreased in the OS group. However, malonaldehyde (MDA) content, reactive oxygen species (ROS) level and apoptosis rate were significantly increased. Compared with the OS group, the morphology of cells and mitochondria in the L-carnitine pretreatment group were improved, the cell viability and the expression of FSHR was significantly increased, and the OS level was decreased. These results indicated that L-carnitine can protect the cells from OS damage induced by H2O2, enhance the antioxidant and anti-apoptotic ability of GCs, and alleviate the decrease of FSHR expression on GCs caused by OS. Therefore, L-carnitine may help prevent the ovarian aging and improve the quality of follicles.