Melittin, an amphipathic 26-residue peptide, is the main component of honey bee venom. Studies have been demonstrated that melittin has an inhibitory effect on proliferation of cancer cells. However, the precise mechanism of action is not completely understood. In the present study we have shown that purified melittin from Iranian honey bee venom shows anti-cancer effects on human cervical cancer cell line through induction of apoptosis. The venom was collected from Iranian honey bee (Apis mellifera meda) and melittin isolated using reversed phase HPLC. Biological activity of melittin was analyzed by hemolytic test on human red blood cells. In order to investigate whether melittin inhibits proliferation of cervical cancer cells, the viability of the melittin treated HeLa cell line was measured via MTT assay. Finally, cell death analysis was performed using Propidum iodide and Annexin V-FITC dual staining. The results showed that the half hemolytic concentration (HD50) induced by mellitin was 0.5 µg/ml in free FBS solution. IC50 obtained after 12 h at 1.8 µg/ml by MTT assay. According to flow cytometric analysis, melittin induced apoptosis at concentrations more than 1 µg/ml. These results suggest that melittin induces apoptotic cell death in cervical cancerous cells as observed by flow cytometric assay. It is concluded that melittin could be regarded as a potential candidate in future studies to discovery of new anticancer agents.

It has been previously reported that melittin, the main ingredient of honey bee venom, has anticancer properties. However, there appears to be no earlier study focusing on the isolation of melittin from Iranian honey bee venom (Apis mellifera meda), and evaluation of its effect on cancerous cells. We isolated melittin using reversed-phase high performance liquid chromatography, and its potential toxicity on gastric cancer AGS cells was determined with an MTT [3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide] assay. Furthermore, to ascertain whether melittin induces apoptosis or necrosis in these cells, morphological evaluation, DNA fragmentation assay, propidium podide and annexin-V-FITC dual staining, and flow cytometric analysis were also conducted. The results of our study suggested that melittin inhibited the proliferation of AGS cells in a dose and time-dependent trend. All of the above four distinct assays indicated that melittin induces necrosis in AGS cells at concentrations of ≥ 1 μg/mL. The present study indicated that melittin has an anticancer effect on gastric cancer AGS cells and stimulates necrotic cell death in these cells.