Effects of honey bee venom on adipose tissue-derived mesenchymal stem cells

Within the scope of this master thesis, effects of complex compound, honey bee (Apis mellifera) venom, on adipose tissue-derived mesenchymal stem cells (MSCs) were investigated. In the first stage, adipose tissue-derived MSCs which were isolated and freezed previously in our studies, were cultured in standard medium conditions and treated with certain concentrations of venom. Dose and time-dependent cytotoxicity of the venom was measured at 4, 24, 48 and 72 h with MTT cell viability analysis. According to these results, 50 mg/ml venom concentration was determined to be applied on cells in the upcoming experimental stage. In the second stage of the study, adipogenic differentiation effect of the venom on adipose tissue-derived MSCs were investigated. For this purpose, positive and negative control groups and venom-applied experimental group were created and the venom group was treated with 50 mg/ml venom concentration during 21 days. Then, Oil Red O staining was performed on 7, 14 and 21 days to observe the neutral lipid droplets inside the cells. When the cells of the negative control group showed no adipogenic differentiation as expected, the cells of the positive control group had lipid droplets observed starting from day four. When two groups (positive control group and venom-applied group) were compared morphologically, it is observed that venom-applied cells showed no hypertrophy and maintained their stem cell morphologies; however, the formation of granular lipid droplets inside the cells was shown by Oil Red O staining. Considering all of these results, for the first time in the literature, it is shown that the honey bee venom led adipose tissue-derived MSCs into adipogenic lineage and induced adipogenesis in these cells without using an adipogenic media. Keywords: Apis mellifera, honey bee venom, adipose tissue-derived MSCs, cytotoxicity, adipogenic differentiation potential, Oil Red O