THE EFFECT OF MELITTIN FROM THE VENOM OF THE BEE APIS MELLEFERA ON PATHOGENIC PARASITES IN VITRO

Abstract

Melittin is the major bioactive peptide of honeybee venom, with membrane active biological properties which could lie the foundation for the anti-parasitic effect. The in vitro effect of melittin prepared from the Iraqi and Italian strains of Apis mellifera on Entamoeba histolytica cysts, Giardia lamblia cyst and Trichomonas vaginalis was evaluated. In addition, a reference preparation of commercial melittin was added. Standardized parasites 1x10⁵ viable trophozoites/mL) were cultured for 24 h in the presence of 0.6 or 0.8 micro mole of melittin. Unless treated, and vehicle, and metronidazole-treated teams were incorporated as controls. The viability of parasites was determined by dye exclusion, hemocytometer and microscopic analysis of motility and morphology. Three biological experiments were independent and each treatment was replicated three times technically. Overall death rates of 0.6 µmol/mL were 70.1% for E. histolytica, 60.7% for G. lamblia and 84.8% for T. vaginalis. At 0.8 µmol/mL, mortality increased to 90.4%, 80.2%, and 90.1%, respectively. The concentration had a significant influence on mortality for all three parasites (p < 0.001). The mean activity was the highest for the commercial one and the Iraqi-bee ones produced comparable effects. These results indicate in vitro anti-parasitic activity that is concentration dependent and this activity needs to be verified by mechanistic, cytotoxicity, and in vivo activity studies.