PERSPECTIVE: Additives to increase the quality of sperm extenders during cryopreservation: a meta-analysis review

According to recent statistics, 40‐50% of infertile are men have numerous extrinsic factors that play a significant role in boosting ROS, which is hazardous to sperm qualities. This meta-analysis study examines which critical and existent additives used in cryopreservation protocols are involved in sperm funtional parameters and counteract the negative impacts of ROS. We analysed the findings of 521 research papers published on PubMed, Scopus, and in various clinical studies, that investigated the effects of sperm extenders with different doses and durations at various in vivo and in vitro stages of sperm handling. We found that over 30-50 components were utilized as additives across multiple study trials. The main function of these additives was to reduce DFI/ROS during the freeze/thaw processes while also sustaining sperm motility and viability. The most effective natural antioxidants were found to be vitamins C and E, L‐phosphatidyl choline, and an extract of the carob plant, Ceratonia siliqua . Overall, most studies employed Ceratonia siliqua as an additive/extender, resulting in maintained motility and morphology with balanced ROS/DFI levels compared to other extenders. Of the animal-derived compounds, AFP‐III was more effective than other stated extenders, exhibiting significant control in semen preservation. Natural additives significantly (p<0.05) increase cell viability and vitality by more than 50‐60% compared to commercially available extenders. Although the present trend is to use additives that are naturally sourced and cost-effective, due to their availability and affordability, concerns remain about the shelf-life of Ceratonia siliqua extract and AFP‐III for use in sperm cells freeze/thaw procedures.