Evaluation of in vitro Genotoxic Potential of Kojic Acid in Human Lymphoblastoid Cells

Abstract

Although kojic acid is used as a cosmetic agent for skin whitening, information of its genotoxicity in in vitro assay is much complicated. In order to evaluate its genotoxic potentials in vitro, we conducted comet assay in regular and acellular versions, chromosome aberration assay, and TK mutation assay in human lymphoblastoid cells. Positive results were obtained in all of the comet, chromosome aberration, and TK mutation assays at almost identical concentration in both TK6 and WTK1 cells. In the acellular comet assay, kojic acid led to positive responses at pH12 and pH13, suggesting that it induced DNA single strand breaks (SSBs). In the TK mutation assay, kojic acid increased the fraction of normal growing but not slowly growing mutants, suggesting that observed gene mutations are due to point mutations within the TK locus but not gross structural changes that can form chromosome aberrations observable by a microscopy.