Evaluation of microbial sperm impairing factors as potential male contraceptives in mouse model

Abstract

Despite significant advances in contraceptive options for women, vasectomy and condoms are the only options available for male contraception. Due to this limitation, the burden of contraception resides on the shoulders of females only. Therefore, there is an urgent need to develop a safe, effective and reversible method of contraception for men. Amongst the alternative approaches, microbial derived products are gaining attention of the scientific world to combat unintended pregnancies. Earlier in our laboratory, sperm impairing microbial factors isolated from Staphylococcus aureus (SSIF), Escherichia coli (E-SIF) and Serratia marcescens (S-SAF) have shown excellent contraceptive efficacy in female mice. Keeping this in mind, the present study was carried out to exploit the sperm impairing factors as potential male contraceptive using different routes (oral/intraperitoneal/intra vas deferens/intra epididymal/ intra testis) for administration in mouse model. For this, sperm impairing factors were isolated and purified from Staphylococcus aureus, Escherichia coli and Serratia marcescens. Further, their contraceptive efficacy was evaluated in the male mouse model up to 90 days with respect to: Body weight profile; Tissue somatic indices; Seminal parameters; Histological changes. After this, impact of intra vas deferens/intra epididymis/intra testis administration of S-SIF/ESIF/SAF on the hematological parameters, serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and testosterone was evaluated. Along with this, levels of reactive oxygen species and cytokines in testes of male mice in response to administration of S-SIF/E-SIF/SAF via intra testis route was assessed. Owing to S-SIF s better potency and efficacy in comparison to E-SIF and S-SAF, S-SIF containing nanoparticles (NPs) formulation was prepared and their contraceptive efficacy was assessed up to 150 days. As, the NPs formulation showed tremendous contraceptive efficacy thus, holds the potential to be exploited as a male contrace