In vitro cytotoxicity, genotoxicity and antioxidant potentials of thymol on human blood cells

Abstract

The aim of this study was to investigate the genetic, oxidative and cytotoxic effects of thymol (THY) in cultured human blood cells (n=5) for the first time. Human blood cells were treated with THY (0–200 mg/L) for 24 and 48 hours, and then cytotoxicity was detected by lactate dehydrogenase (LDH) release and [3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide] (MTT) assay, while DNA damage was also analyzed by micronucleus (MN) assay, sister chromatid exchanges (SCE) assay and 8-oxo-2-deoxyguanosine (8-OH-dG) level. In addition, biochemical parameters (total antioxidant capacity [TAC] and total oxidative stress [TOS]) were examined to determine oxidative effects. In our in vitro test systems, it was observed that THY had no mutagenic effects on human lymphocytes. On the other hand, THY (at 25, 50 and 75 mg/L) treatment caused statistically important (p < 0.05) increases of TAC levels and increases of TOS levels (only at 200 mg/L) on cultured human blood cells. According to the results of LDH assay, THY induced cytotoxicity on cultured human blood cells in a time- and dose-dependent manner, and THY (at concentrations above 100 mg/L) decreased cell viability. These results suggest that THY may be the therapeutic antioxidant potential in different diseases.

Keywords:

• cytotoxicity
• oxidative effects
• thymol

Acknowledgements

The authors are grateful to all volunteers for the blood samples.