[Effect of combination of Melatonin and All-Trans retinoic acid on maturation, fertilization and embryonic development of immature mouse oocytes]

Background and Objective: With respect to the antioxidant role of melatonin and retinoic acid, it seems to be effective both in the maturation and embryonic development. This study was done to investigate the effect of combination of melatonin and All-Trans retinoic acid [RA] on maturation, fertilization and embryonic development of immature mouse oocytes

Methods: In this experimental study, cumulus - oocyte complex [COCs] were recovered from 4-6 week old female mice NMRI and were divided into 6 maturation medium groups including control, sham, experiment 1[melatonin 100 nM, 1 and 2 microM], experiment 2 [retinoic acid 1, 2, 4, 6 microM], experiment 3 [melatonin 2 microM+RA 4 microM], experiment 4 [Mel 100nM + retinoic acid 4 microM]. The maturation rate was recorded after 24 hours of culture in a humidified atmosphere of 5% CO2 at 37°C. The matured oocytes were fertilized with sperm. Fertilization and embryonic development rates to the blastocyst stage were recorded

Results: Maturation rate in the control and sham groups were 50.6% and 49.4%, respectively. Maturation rate were 54.3%, 54.8%, 59.9% in melatonin group with concentrations of 100 nM, 1 and 2 microM, respectively. Maturation rate were 51.6%, 51%, 59% and 49.6% in t-RA group with concentrations of 1, 2, 4, 6 microM. Maturation rate were 60.4% and 54.2% in the experiment 3 and 4 groups, respectively. The maturation rates in the melatonin 2 microM, retinoic acid 4 microM and experiment 3 significantly increased in compare to control [P<0.05]. The embryonic development rate in the melatonin with 100nM concentration and 4 microM of retinoic acid increased significantly compared to controls [P<0.05]. Although, embryonic development rate in experiment 3 was higher than control, but lower in compare to melatonin 100 nM and the retinoic acid 4 microM. The embryonic development rate in experiment 4 significantly increased in compare to control [P<0.05]

Conclusion: Combination of melatonin and All-Trans retinoic acid in medium culture increase maturation rate and improved embryonic development in dose dependent manner

[Effect of antioxidants supplementation on human sperm parameters after freezing]

Antioxidant reduces oxidative stress during cryo-preservation. The aim of this study was to find out the effects of vitamin E and C on sperm parameters after cryo-preservation. Human semen samples were obtained from Vali-e-asr Hospital. The samples were divided in two groups [normal and oligospermia groups]. Semen was pooled in liquid nitrogen after thawing, samples were centrifuged, then vitamin E and C were added to medium and the aliquots were incubated for 45 minutes in incubator Co2. In control group, no antioxidant was added to medium. Sperm parameters were analyzed according to WHO criteria. Data was analyzed by ANNOVA test. There was a significant increase in the progressive motility and viability of sperm which was supplemented by vitamin E, with 1, 2 Mm [p<0.05] in the normal groups [the increase in the oligospermia group, after addition of vitamin E with 1, 2, Mm was not significant]. Vitamin C did not have a significant effect on sperm parameters with 1, 2 Mm concentration. Supplementation of media with alpha-tocopherol is beneficial for sperm motility and viability rates after cryopreservation and it may be of clinical value in assisted conception procedures