M Mohammadzadeh - Department of Reproductive Biology, Yazd Reproductive Sciences Institute, Research and Clinical Center for Infertility, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
E Farashahi-Yazd - Stem Cell Biology Research Center, Yazd Reproductive Sciences Institute, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
L Motamedzadeh - Department of Reproductive Biology, Yazd Reproductive Sciences Institute, Research and Clinical Center for Infertility, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
F Anbari - Department of Reproductive Biology, Yazd Reproductive Sciences Institute, Research and Clinical Center for Infertility, Shahid Sadoughi University of Medical Sciences, Yazd, Iran

Background: Aging led some changes in the male reproductive system, including reducing sperm parameters, increasing DNA deficiency. Consequently, the fertilization process is compromised. Studies have shown the use of exogenous estrogen solve some of the infertility problems. Also, the use of sesame oil as an antioxidant, protect sperm function from oxidative stress, as well as, use of antioxidant is recommended to improve sperm function. Objective: Therefore, our aim of this study was achieved an appropriate dose of estradilo with sesame oil to optimize sperm parameters and chromatin.Materials and Methods: Twenty-five old mice age range of 25-35 wk were divided into five groups: 1(control, without treatment), 2 (estradiol 100 μg/ml)), 3 (estradiol 10 μg/ml), 4 (estradiol 1 μg/ml) and 5 (Sesame oil). To each group, 10μl of treatment fluid was injected by IP method during 35 days, after that epididymal sperms were analyzed in terms of sperm parameters and chromatin and DNA status using Aniline Blue (AB), Tunel assay and Chromomycin A3 (CMA3) staining.Results: The highest sperm motility belonged to group 3 (E210 μg/ml),. The lowest sperm count and motility were seen in groups 2 (E2 100 μg/ml) this result was significant (p=0.004). Findings from sperm with arrest maturity was higher in high concentration than low concentration of estradiol and sesame oil therefore it has been shown a significant difference between groups (p=0.000). Sperm chromatin Integrity was a significant reduction in 100 μg/ml of estradiol but, in Sesame oil group and estradiol with 10 μg/ml, Sperm chromatin Integrity was more than other groups (p=0.037). In control and high concentration estradiol, the rate of DNA fragmentation was higher than in low concentration of estradiol (10 μg/ml) and Sesame oil but, there was no significant difference between groups.Conclusion: This study showed that a low concentration of estradiol (E210 μg/ml) and Sesame oil improve the sperm parameters and chromatin Also, the Sesame oil as potent antioxidant had a better effect in low cicentration of estradiol than high concentrations.

Estradiol, Old mice, Sperm parameters, Sesame oil, chromatin status, DNA integrity