Genotoxic Evaluation of Linalool in Neuronal PC12 Cells

Linalool is one of the main constituents of the essential oil of some aromatic plants, including Lavandula angustifolia. It is used in cosmetics and pharmaceutical industry. In this study, the cytotoxicity and genotoxicity of (±) linalool and its naturally occurring enantiomer, (R)-(-) linalool, were evaluated in neuronal PC12 cells.

PC12 cells were incubated with different concentrations of racemate linalool and (R)-(-) linalool for 12 and 24 h. Cytotoxicvity and genotoxicity were evaluated using MTT assay and single cell gel electrophoresis (comet) assay, respectively.

Findings showed that (±) linalool and (R)-(-) linalool (3200 μM) significantly reduced cell viability to 76.2% and 92%, compared to the control group (untreated cells) (P<0.001). IC50 values after 12 h and 24 h exposure to (±) linalool and (R)-(-) linalool were 2700 µM and 5440 µM, and 2600 µM and 3040 µM, respectively. Following treatment by (±) linalool or (R)-(-) linalool for 12 or 24 h, the DNA contents in the comets tail, as an indicator of genotoxicity, significantly increased to 21.36 ± 3.1%, 27.6 ± 2.3% and 15.2 ± 1.6% and 21.3 ± 2%, respectively (P<0.001).

In this study, racemate linalool and its enantiomer, (R)-(-) linalool, decreased the viability of PC12 cells via induction of genotoxicity. (R)-(-) linalool exhibited more cytotoxicity than (±) linalool.