In Vitro Cytotoxicity Testing of Novel Drug Molecules Using MTT Assay
Mr. Ankush Biswas Mr. Ankush Biswas, Mrs. Pritha Singha Roy Mrs. Pritha Singha Roy, Akashdip Pal Akashdip Pal, Subhadip Ghosh Subhadip Ghosh, SK Heyat Kalendar SK Heyat Kalendar, Debajyoti Biswas Debajyoti Biswas · International Journal of Pharmaceutical Research and Applications · 2025
Cytotoxicity testing using in vitro models is a fundamental step in drug discovery to evaluate the potential toxicity and therapeutic index of novel drug candidates. Among the various available assays, the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyl tetrazolium bromide) assay is a widely used, cost-effective colorimetric method to measure cellular metabolic activity and viability. This study aimed to investigate the cytotoxic effects of three newly synthesized drug molecules (ND-1, ND-2, and ND-3) on human cancer cell lines—HeLa (cervical cancer) and MCF-7 (breast cancer)—as well as on the non-cancerous HEK293 cell line (human embryonic kidney cells). Cells were treated with different concentrations of the compounds, and the MTT assay was performed after 24 and 48 hours to assess cell viability. The results showed a dose-dependent reduction in cell viability, with ND-2 displaying the most potent cytotoxicity against MCF-7 cells, having an IC₅ ₀ of 8.4 µM. ND-3 demonstrated comparatively lower toxicity to normal HEK293 cells, indicating a better selectivity index. The study confirms the efficacy of the MTT assay in screening cytotoxic effects of novel compounds and identifies ND-2 and ND-3 as promising leads for further anticancer evaluation. These findings suggest the utility of integrating in vitro cytotoxicity profiling early in drug development pipelines.