Effect of gibberellic acid on the quality of sperm and in vitro fertilization outcome in adult male rats

Gibberellic acid (GA۳) is a group of plant hormones identified in various plants. The aim of this study was to determine the effects of GA۳ on sperm parameters and in vitro fertilization (IVF). Fifty six adult male rats were divided into seven groups as, control, treatment and sham. Following ۱۵, ۳۰ and ۴۵ days of GA۳ and methanol alcohol (MA) administration, rats were euthanized and epididymis tail was transferred to human tubular fluid (HTF) medium containing ۴ mg mL-۱ bovine serum albumin (BSA) .Total number of sperms, the percentage of live sperms, immature sperms and sperms with damaged chromatin and IVF were examined. The oocytes were obtained from immature rats after the injection of pregnant mare's serum (PMSG) and human chorionic gonadotropin (HCG) hormones. Human tubular fluid was used as the fertilization medium and zygotes transferred to fresh ۱-cell rat embryos culture medium (mR۱ECM) to reach the blastocyst stage. This study showed that GA۳ could decrease the number of total sperms on days ۳۰ and ۴۵ in treated group comparison with the control and sham groups. Additionally, GA۳ increased the immature sperms and sperms with damaged chromatin. The percentage of fertilization, two-cell embryos and blastocyst resulting from the treatment group on days ۳۰ and ۴۵ also decreased and showed significant differences with the control and sham groups (p < ۰.۰۵). The results obtained from this study indicated that the oral use of GA۳ could reduce the fertility in rats by influencing the sperm number and the quality of sperm’s chromatins.