The Antioxidative Effects Of L-carnitine On Human Ovarian Granulosa Cells

Objective:To investigate the antioxidative effects of L-carnitine on human ovarian granulose cells in vitro and in vivo and to explore its mechanism.Methods:The study was divided into two parts. The first part was to investigate the antioxidative effects and mechanism of L-carnitine on human ovarian granulose cells in vitro.Human ovarian granulosa cells were from40infertility patients (40cycles).20cases for intracellular reactive oxygen species (ROS) levels,20cases for mitochondria membrane potential (MMP) levels.Collected follicular fluid of infertility patients in our reproductive center after ovulation. After cultured ovarian granulosa cells24hours, culture medium was replaced added containing different concentrations of L-carnitine (Oμmol/L,20μmol/L,40μmol/L, and80μmol/L) for another24hours. Collected each L-carnitine-treated group cells to detect intracellular reactive oxygen species (ROS) and mitochondrial membrane potential (MMP) by flow cytometry. The second part study the oral administration of L-carnitine antioxidant effects on infertility patients ovarian granulosa cells.70cases (70cycles) were randomly divided into oral L-carnitine group (treatment group)35cases and without oral administration of L-carnitine group (control group)35cases.Oral L-carnitine group began to oral carnitine oral liquid0.1g twice daily from the first visit to oocyte picking-up day, the average treatment time were (72.4±8.7) days. Follicular fluid were collected after oocyte picking-up to detect glutathione (GSH) levels by the application of the722spectrophotometer with DNTB as a probe.Results:In vitro culture experiments, intracellular ROS levels was decreasing with concentration of L-carnitine increasing, the differences among each group were statistically significant (χ2=16.800, P=0.001). Mitochondrial membrane potential levels were increasing with concentration of L-carnitine increasing.The performance of flow cytometry was as green fluorescence decreasd but red fluorescence increased.The differences among each groups were statistically significant (χ2=11.185, P=0.011). In vivo experiment, difference of the follicular fluid GSH levels between oral L-carnitine group and control group was with no statistical significance(Z=-1.427, P=0.154).Conclusion:In vitro, L-carnitine improve the antioxidant effects of ovarian granulosa cells by reducing ROS and keeping MMP.But the effect of oral L-carnitine on GSH in the follicular fluid is not obvious.