Abstract: Objective: To investigate the genetic toxicity and its mechanisms of kojic acid. Methods: Bone marrow micronucleus test in mice and comet assay in CHO-K1 cells were used to examine DNA damage. KM mice were randomly divided into 5 groups for 5 males and 5 females in each group. The KM mice were administered with kojic acid at doses of 1/2, 1/4, and 1/8 fold LD50 for examining DNA damage. CHO-K1 cells were treated with kojic acid at the concentrations of 0, 500, 1000, 1500, 2000 μg/mL and 2500μg/mL for comet assay at 6, 12, 24 h and 48 h, respectively. Results: After treatment with kojic acid, the ratio of micronucleus in mice did not exhibit a significant increase, compared with the negative control. The slight DNA damage in CHO-K1 cells was observed in kojic acid group at the concentration of at 1000μg/mL after 6 h incubation. Severely DNA damage was also observed when kojic acid concentration was increased to 2500μg/mL. However, no response-time relationship was observed. Conclusion: Kojic acid at the experimental conditions did not result in genetic toxicity in bone marrow cells of treated mice, but could induce DNA damage in vitro at high concentration level.

Key words: kojic acid, cell line, micronucleus test, comet assay