In Vitro Cytotoxicity Evaluation of Troglitazone, Rosiglitazone and Pioglitazone in HepG2 Cells

The objective of this research work was comparative evaluation of in vitro cytotoxicity of troglitazone, rosiglitazone and pioglitazone in HepG2 cells. Briefly, the HepG2 cells were exposed to multiple concentrations (3.125–100 µM) of three drugs (troglitazone, rosiglitazone and pioglitazone) for 12 h, 24 h and 48 h. At the end of each treatment period, cytotoxicity was determined using multiple end points such as 3-[4,5-imethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay, neutral red assay and lactate dehydrogenase leakage assay. Troglitazone showed time and concentration dependent cytotoxicity in all three end points with evident cytotoxic effects being observed at 50 and 100 µM concentrations. MTT assay showed higher cytotoxicity and early onset compared to neutral red and lactate dehydrogenase leakage assay at all time points. There was no cytotoxicity observed for rosiglitazone at all tested concentrations up to 100 µM. Similarly, pioglitazone also did not affect the viability of HepG2 cells up to the concentration of 50 µM however some cytotoxicity was noted at 100 µM concentration which could be partly attributed to the precipitation of test compound noted at 100 µM concentration after addition to the culture medium. The results from this research work indicated that among the three drugs tested in this study, only troglitazone induced time and concentration dependent toxicity in the HepG2 cells in all three end points with MTT assay being the most sensitive assay.