Isolating Melittin from Bee Venom and Evaluating its Effect on Proliferation of Gastric Cancer Cells

Background and Gastric cancer (GC) is one of the most common cancers worldwide and in Iran. As conventional therapies such as surgery and chemotherapy are invasive with adverse effects, current studies are important as they are conducted to find natural compounds with few adverse effects. In this study, melittin with 26 amino acids was isolated and purified from bee venom and its effect on the viability and proliferation of gastric cancer cells was investigated. At first, melittin was purified from honeybee venom by a reversed-phase high performance liquid chromatography (RP- HPLC) and using C18 column. The biologic activity of melittin was evaluated by hemolytic test on red blood cells to melittin standard. To investigate the effect of melittin on viability and proliferation of AGS human gastric adenocarcinoma cells, the related cells were cultured in a 96-well plate and treated with serially diluted concentrations of melittin for 6 and 12 hours and their mortality was determined by MTT [(3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] colorimetric method at 540 nm wavelengths. The obtained chromatogram from RP-HPLC showed that melittin comprised 50% of the studied bee venom. SDS-PAGE analysis of melittin fraction confirmed purity of isolated melittin. Hemolytic assay showed that the extracted melittin indicates a strong hemolytic activity (HD50=0.55μg/ml). MTT assay showed that melittin strongly inhibits proliferation of gastric cancer cells at concentrations more than 2μg/ml. This inhibitory effect depends on melittin concentration and time. The results of this study showed that melittin is a strong inhibitor of proliferation of the gastric cancer cells. Also, it was observed that this inhibitory effect is increased with increasing concentrations of melittin and incubation time.