Determining the Population Doubling Time of HepG2 and Huh-7 Cells and the Toxic Effect of Dimethyl Sulfoxide (DMSO)

Abstract

Developing cell lines that carry promising qualities closest to human hepatocytes in drug studies is a dream of many research laboratories. About 90% of drugs are metabolised by the liver. Therefore, most drug discovery studies utilise hepatocytes to understand the basic mechanism of the drug’s breakdown. To assure hepatocytes survival, various solvents were tested for their cytotoxicity on the cell line. Since most drugs are weakly soluble in water, they can be dissolved in an aprotic solvent. To obtain accurate results, the requirements of these solvents are biocompatible and non-toxic to the cells. One of the most commonly used solvents is dimethyl sulfoxide (DMSO). This study aims to understand the cell characteristic of cells doubling time and investigate the toxic effect of DMSO using the cell proliferation measurement technique. The toxicity was measured on liver-derived cell lines HepG2 and Huh-7. Cell growth and morphology were observed with an inverted phase microscope while cell viability was counted using Vi-Call XR 2.03. Results showed that a doubling time of 32 hours would be best for treatments on both cells. A concentration of more than 0.40% DMSO has significant toxicity and caused inhibition of proliferation on both cell lines, resulting in low cell count and higher cell death. Ethanol and methanol were observed as good solvents since they have low toxicity. However, drugs that were only dissolved in a low concentration of DMSO (0.05-0.2%) gave the best result without any harmful effect on cell proliferation.