Improvement of the functionality of pancreatic Langerhans islets via reduction of bacterial contamination and apoptosis using phenolic compounds

OBJECTIVE(S): During type-1 diabetes treating by pancreatic islet transplantation, increasing oxidative stress and microbial contaminations are the main reasons of transplantation failure. In this study, we evaluated anti-apoptotic, antioxidant and antimicrobial potentials of phenolic compounds called ellagic acid (EA) and silybin on rat pancreatic islets. MATERIALS AND METHODS: By doing MTT assay, effective concentrations of EA and silybin were determined as 1500 and 2100 μM, respectively. Then, ELISA methods, flow cytometry and MIC were done to investigate antioxidant, anti-apoptotic and antibacterial effects of those compounds, respectively. RESULTS: Results of FITC Annexin-V and PI staining via flow cytometry, and also caspase-3 and -9 activities performed that EA has anti-apoptotic effects on pancreatic cells. Both compounds significantly diminished reactive oxygen species, and enhanced antioxidant power and insulin secretion. Furthermore, the minimum inhibitory concentration test indicated that these two have antibacterial effects on both Gram-positive and Gram-negative bacteria which usually contaminate the pancreatic islets. CONCLUSION: These findings support that use of EA and silybin can improve the function of islets which are used in transplantation, along with decreasing islets bacterial contamination.