Linalool Effect on HepG2 cells: Structure Function Relation

Linalool is a monoterpene that is widely used in fragrance industry and cosmetics. The effect of linalool on cultured cells (HepG2, MCF7, Hek293, Caco2 and NIH3T3) was investigated. We have recently reported a significant decrease of 50% and 100% in the viability of HepG2 by 0.4µM and 2µM linalool, respectively (1). Other studies reported the cytotoxicity of linalool on hematopoietic malignancies but not on normal human cells (2). These findings identify linalool as a potential anticancerogenic molecule.

The aim of this study was to investigate the importance of the structural features of linalool in exerting the effect on HepG2 cells.

Eleven chemicals with were tested. HepG2 cells were treated with various chemicals at 2–500µM for 24 hours and the viability was estimated using MTT.

None of the screened compound had the same potent effect of linalool (2µM). No effect was demonstrated at concentrations lower than 50µM. We obtained cell death in HepG2 74% with myrcene & nerolidol (100µM); 55% with trans-2-nonenal, Decanal (100µM); 20% with Nonyl aldehyde, citronellal, citronellal, citral, Perillaldehyde, trans-2-octen1-ol, and 1-octen-3-ol at (500µM).

Our findings suggest that the effect of linalool is specific to 1-ene 3-ol moiety. The hydroxyl group needs be tertiary. Hydration of myrcene and L-perillaldehyde did not have any significant effect on HepG2 viability. This may be attributed to: favorability of the hydration reaction and to possible steric effect. Alternative metabolism of linalool into other products may not be ruled out.

Acknowledgement: Medical Practice plan and University Research Board of the American University of Beirut

References: 1. Usta J et al. (2009) Chem-Biol Interact 180: 39–46

2. Gu Y et al. (2010) Toxicology 268: 19–24