Genotoxicity assessment of piperitenone oxide: an in vitro and in silico evaluation

Piperitenone oxide, a natural flavouring agent also known as rotundifolone, has been studied for the genotoxicity assessment by an integrated in vitro and in silico experimental approach, including the bacterial reverse mutation assay, the micronucleus test, the comet assay and the computational prediction by Toxtree and VEGA tools. Under our experimental conditions, the monoterpene showed to induce both point mutations (i.e. frameshift, base-substitution and/or oxidative damage) and DNA damage (i.e. clastogenic or aneuploidic damage, or single-strand breaks). Computational prediction for piperitenone oxide agreed with the toxicological data, and highlighted the presence of the epoxide function and the α,β-unsaturated carbonyl as possible structural alerts for DNA damage. However, improving the toxicological libraries for natural occurring compounds is required in order to favour the applicability of in silico models to the toxicological predictions. Further in vivo evaluations are strictly needed in order to evaluate the role of the bioavailability of the substance and the metabolic fate on its genotoxicity profile. To the best of our knowledge, these data represent the first evaluation of the genotoxicity for this flavour compound and suggest the need of further studies to assess the safety of piperitenone oxide as either flavour or fragrance chemicals.