L-Carnitine decreases DNA damage and improves the in vitro blastocyst development rate in mouse embryos  Hussein Abdelrazik, M.D., Rakesh Sharma, Ph.D., Reda Mahfouz, M.D., Ashok Agarwal, Ph.D.  Fertility and Sterility  Volume 91, Issue 2, Pages 589-596 (February 2009) DOI: 10.1016/j.fertnstert.2007.11.067 Copyright © 2009 American Society for Reproductive Medicine Terms and Conditions

Figure 1 Confocal photomicrographs of mouse blastocyst stained for apoptosis. All nuclei of the blastocyst are labeled with 4′,6′-diamidino-2-phenylindole hydrochloride (blue channel) and terminal deoxynucleotidyl transferase–mediated dUTP nick-end labeling (green channel). (A) Control group; (B) human tubal fluid (HTF) medium + 0.3 mg/mL L-carnitine (LC); (C) HTF medium + 0.6 mg/mL LC. Significant improvement in blastocyst development rate (%BDR) was seen at LC 0.3 mg/mL compared with control (100% vs. 83.3%; P=.006). No significant change was seen in the level of apoptosis in embryos cultured in 0.3 and 0.6 mg/mL LC (P=.13 and P=.42, respectively). (D) Actinomycin-D 0.005 μg/mL; (E) actinomycin-D + 0.3 mg/mL LC; (F) actinomycin-D + 0.6 mg/mL LC. Treatment of the embryos with actinomycin-D at 0.005μg/mL for 4 h significantly increased the level of apoptosis (P<.001) compared with control. A significant decrease in the level of apoptosis induced by actinomycin-D also was seen in embryos treated with 0.3 and 0.6 mg/mL LC (both P<.001). Scale bar = 10 μm. Fertility and Sterility 2009 91, 589-596DOI: (10.1016/j.fertnstert.2007.11.067) Copyright © 2009 American Society for Reproductive Medicine Terms and Conditions

Figure 2 Confocal photomicrographs of mouse blastocyst stained for apoptosis. All nuclei of the blastocyst are labeled with 4′,6′-diamidino-2-phenylindole hydrochloride (blue channel) and terminal deoxynucleotidyl transferase–mediated dUTP nick-end labeling (green channel). (A) Hydrogen peroxide (H2O2) 500 mmol/L; H2O2 at this concentration arrested more than 92% of the embryos. (B) H2O2 + 0.3 mg/mL L-carnitine (LC); (C) H2O2 + 0.6 mg/mL LC. Incubation of mouse embryos in 500 μmol/L H2O2 significantly increased the level of apoptosis (P<.001) compared with control. There was no significant difference in apoptosis level in H2O2 + 0.3 or 0.6 mg/mL LC compared with control (P=.34 and P=.37, respectively). L-Carnitine at 0.3 and 0.6 mg/mL concentration significantly decreased the level of apoptosis (P<.006 and P<.007, respectively) compared with the group treated with H2O2 alone. (D) Tumor necrosis factor α (TNF-α) 500 ng/mL; (E) TNF-α + 0.3 mg/mL LC; (F) TNF-α + 0.6 mg/mL LC. Incubation of two-cell mouse embryos with 500 ng TNF-α significantly decreased the %BDR (P<.001) but did not increase the level of apoptosis (P=.48) compared with control or with 0.3 and 0.6 mg/mL LC groups (P=.59 and P=.62, respectively). Scale bar = 10 μm. Fertility and Sterility 2009 91, 589-596DOI: (10.1016/j.fertnstert.2007.11.067) Copyright © 2009 American Society for Reproductive Medicine Terms and Conditions