CYTOTOXICITY STUDY OF ANTIDIABETIC PLANTS ON NEUROBLASTOMA CELLS CULTURED AT NORMAL AND HIGH GLUCOSE LEVEL

Objective : In diabetes, chronic hyperglycemia causes damage (glucose toxicity) on some cells leading to micro and macro vascular complications. The aim of this study was to investigate the effect of antidiabetic plants extracts in high glucose concentration in vitro . Methods: Phyllanthus amarus (whole plant), Vitex doniana (leaves), Tectona grandis (leaves and trunk bark) and Plumeria alba (roots) hydroalcoholic extract (at the concentrations of 6.25, 25, 75, 125, 250 and 500 µg/ml) were tested for their possible cytotoxicity using the 3-(4,5-dimetylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay on neuroblastoma cells lines in standard condition (extract alone) and high glucose concentration (extract+50 mM glucose). Results: At concentrations of 6.25 and 25µg/ml, T. grandis bark and leaves and P. amarus induced a significant decrease ( p<0.01; p<0.001 ) on cell viability as compared to controls. The decrease on cell viability was very pronounced in the presence of the extracts plus glucose 50 mM. P. amarus extract becomes increasingly toxic as the concentration of extract increased in the presence of glucose. With P. amarus at 125 µg/ml and glucose at 50 mM, there is no more viable cells in the medium. By contrast, T. grandis bark extract induced a significant reduction of the cytotoxicity in the presence of glucose compared to standard condition. Conclusion : It appears that, only hydroalcoholic extract of T. grandis bark possesses neuroprotective activity in high glucose concentration.