Evaluating the spermicidal activity of an antimicrobial peptide from the Bufo kavirensis, MaximinBk: in vitro study

Abstract

AbstractObjective:The aim of this study was to evaluate the spermicidal activity of this peptide to introduce a new potent agent for prevention of sexually transmitted infections and unplanned pregnancies.Methods:The purified MaximinBk (with amino acid sequence: ILGPVLGLVGRLAGGLIKRE) was diluted with Ham’s F10 solution in 100, 200, 400, 600, 800 and 900 μg/mL. One milliliter from peptide solution with different dosage was mixed with 200 μL prepared sperm solution in microtube. Sperm motility, viability and morphology were assessed at different time intervals (0.3, 5, 10, 15 min). Eosin–Nigrosin staining and Giemsa staining methods were applied for sperm viability and morphology detection, respectively.Results:Total spermicidal activity was shown after addition of 900 μg/mL for 0.3 min without any morphological change in the sperm head, midpiece or tail. Also, Eosin–Nigrosin staining indicated MaximinBk can disturb membrane integrity of normal sperm that is in dose-dependent manner.Conclusion:MaximinBk has spermicidal activity in addition to antimicrobial activities (especially on vaginal infections such as candidal vulvovaginitis). It seems this peptide might be a potential candidate in order to use in male contraception, although, this preliminary study needs more studies to elucidate final conclusion.