EVALUATION OF CYTOTOXIC EFFECT OF ZINC ON MOLT-4 CELL-LINE BY MITOCHONDORIAL THIAZOL TETRAZOLIUM ASSAY

Zinc has important effects on structural and functional activities of many proteins and enzymes involved in biological activities especially regulation of immune- system. Deficiencies of this element may result in many diseases and immunological disorders. Symptoms of zinc toxicity include nausea/vomiting, fever, cough, diarrhea, fatigue, neuropathy and dehydration.  Further signs include growth retardation, altered iron function, anemia, copper deficiency, decreased immune function, decreased HDL (high density lipoprotein), increased LDL (low density lipoprotein), and increased HgbA1C. This study was carried out to examine the in vitro effects of different concentration of zinc on viability and death of T-Lymphoid (Molt-4) cell line. In this study, the cell line was exposed to different concentrations of zinc (10nM to 500µM) followed by incubation (37°C, 5% CO₂) at various time points (12 to 72 h). The cells were then evaluated with trypan blue exclusion dye and Mitochondorial Thiazol Tetrazolium Assay (MTT) and light microscopy. The results of this study showed almost different responses to different amounts of zinc by The T cell line (Molt-4). Zinc concentrations below 100µM at different incubation time points had little or no effect on cell line compared to the controls.  Higher concentrations of zinc (>100µM) viability diminished to 70% at 12 h and less than 50% at 24 to 72 h of incubation times. We conclude that Zinc has dose-dependent cytotoxicity on Molt-4 cells.