Genotoxicity assessment of β-caryophyllene oxide.

β-caryophyllene oxide is a biciclic sesquiterpene, occurring naturally in essential oils from various medicinal and edible plants and used as a flavouring agent. Due to its potential hazardous chemical structure, the European Food Safety Authority reported to be pending a safety assessment for this compound. Here, this flavouring agent was tested for its mutagenic effect in the Ames test and micronucleus assay. Furthermore, considering that the penetration of a substance through phospholipid bilayers is determinant for its activity, the ability of β-caryophyllene oxide to be absorbed into cells was evaluated by differential scanning calorimetry (DSC) using multilamellar vesicles of dimyristoylphosphatidylcholine as a biomembrane model. β-caryophyllene oxide was found to be devoid of mutagenic effect, both at gene level (frameshift or base-substitution mutations), and on chromosome (clastogenicity and aneuploidogenicity). Results of DSC analysis highlighted that the substance was strongly absorbed through the membrane bilayer. Present results show that β-caryophyllene oxide, although absorbed through cell membranes and in spite of its potentially reactive chemical structure, is devoid of genotoxic effects, inducing neither point mutations nor chromosomal damages. These negative genotoxic findings will be critical to the safety assessment of β-caryophyllene oxide as used as a flavouring/fragrance ingredient.