L-Carnitine decreases DNA damage and improves the in vitro blastocyst development rate in mouse embryos

Objective: To optimize the L-carnitine (LC) concentration as a supplement in embryo culture medium and to investigate the effect of LC on developing embryos. Design: Experimental study. Setting: Reproductive research center at a tertiary hospital. Intervention(S): To optimize the LC concentration, 420 mouse embryos were divided into seven groups and incubated with different LC concentrations (0, 0.3, 0.6, 1.2, 2.5, 5.0, and 10 mg/mL). To investigate the effect of LC on the developing embryos, 500 mouse embryos were divided into three groups and incubated with either actinomycin-D (AD; 0.005 mu g/mL), hydrogen peroxide (H2O2; 500 mu mol/L), or tumor necrosis factor alpha (TNF-alpha; 500ng) with and without LC 0.3 or 0.6 mg/mL. Blastocyst development rate (%BDR) and DNA damage were examined for all groups. Main Outcome Measure(s): Effect of LC on embryogenesis. Result(s): Significant improvement in %BDR was seen at LC 0.3 mg/mL compared with the control (p = 0.006). L-Carnitine at 0.3 and 0.6 mg/mL significantly reduced the blocking effect of AD, H2O2, and TNF-alpha and significantly decreased the level of DNA damage. Conclusion(S): Embryo culture medium supplementation with LC may offer a novel and a cost-effective technique to improve the embryogenesis of cultured embryos. This may be beneficial in improving IVF outcomes. (Fertil Steril(R) 2009;91:589-96. (C)2009 by American Society for Reproductive Medicine.)