Genotoxicity of rice bran oil extracted by supercritical CO2 extraction.

Rice bran oil extracted by supercritical CO2 extraction (RB-SCE) reportedly exhibits pharmacological activities such as antioxidant and in vivo hair growth-inducing effects. Such activities raise the possibility of the development of novel hair growth-inducing agents using RB-SCE. The aim of this study was to investigate the potential genotoxic effects of RB-SCE in three short-term mutagenicity assays (bacterial reverse mutation assay, in vitro mammalian chromosomal aberration test, and in vivo micronucleus assay). RB-SCE showed no genotoxicity in the bacterial reverse mutation assay up to 5000 mg/plate and in the in vivo micronucleus test up to 600 mg/kg body weight. However, at 120 µg/mL with S9 mix and 200 µg/mL without S9 mix RB-SCE showed significantly different genotoxicity than the negative control in the in vitro chromosome aberration test. The induction of chromosomal aberrations under the present conditions may have no biological significance. We have herein demonstrated that RB-SCE can be regarded as a non-genotoxic material based on the available in vivo and in vitro results.