The spermicidal effect of the honeybee Apis mellifera venom and its major component melittin

Several spermicide products are currently used containing detergent as the active ingredient. Those molecules showed a bad effect on normal vaginal epithelial cells and microflora. They also increase the possibility of cervical or vaginal infections or ulceration. In this study, the possible effects of crude bee venom (BV) of the honeybee (Apis mellifera) and its common bioactive peptides on human sperm motility were evaluated in vitro. Serially diluted BV and its bioactive peptides at noncytotoxic concentrations were tested for sperm immobilization by Sander-Cramer assay. The sperm viability test and the hypo-osmotic swelling were used to check the vitality and the integrity of the sperm membrane. Sperm morphological alterations were evaluated by a light microscope and scanning electron microscope. Results showed that BV at 3.0 μg/ml concentration was significantly immobilized and killed 100% (1.0 million) of the human sperm within 20 seconds. Similarly, the small peptide MLT showed immediate and complete sperm immobilization at 6.7 µg/ml. Moreover, apamin induced a moderate effect on sperm motility at 10.0 μg/ml, whereas mast cell degranulating peptide showed no effect on sperm motility up to 10.0 μg/ml. In conclusion, the current study indicates that BV and MLT have a spermicidal effect and exert their spermicidal activity through a direct lysis effect on the plasma membranes of sperm heads.