Background: Transient Receptor Potential (TRP) channels have been implicated in playing a crucial role in several intracellular signal transduction mechanisms throughout the body. A hallmark characteristic of these ligand-gated ion channels is their relative polymodal nature of activation. Through collaborations with investigators at Montana State University, we investigated the extent to which 7 different essential oils (EO) extracted from Ferula iliensis stimulate calcium influx through TRPV1-transfected human embryonic kidney (HEK) cells.
Methods: TRPV1-transfected HEK cells were utilized for all protocols. In order to quantifiably determine the extent to which EO’s 1-7 elicit calcium influx, we utilized fura 2 and fluo 4 loaded cells for real-time intracellular calcium measurements and calcium assay preparations, respectively. Cells were treated with the test compounds in the presence or absence of TRPV1 inhibitor peptide, SB366791. Results were analyzed using Sigmaplot 11.0 software.
Results: The current data suggests that several EO’s stimulated calcium influx; however, two compounds, trans-2-nonenal and geranylacetone, were demonstrated to act directly through TRPV1. In the calcium assay, trans-2-nonenal and geranylacetone induced calcium influxes into TRPV1-transfected HEK cells. Comparative results were observed in real-time calcium measurements where trans-2-nonenal and geranylacetone stimulated transient increases in intracellular free calcium concentrations in TRPV1-transfected HEK cells. These effects were diminished in the presence of SB366791.
Conclusions: Herein, we identified trans-2-nonenal and geranylacetone as two novel agonists of TRPV1. The extent to which these agonists modulate intracellular signaling events in the heart will be of great translational interest and will be subject of future investigations.
Derek Damron Ph.D
Spencer Andrei B.S.
Monica Ghosh M.S.
Manasi Agrawal M.S.
We investigated 7 different essential oils (EO) extracted from Ferula iliensis that stimulate calcium influx through transient receptor potential channel of the vanilloid subtype 1 (TRPV1)-transfected human embryonic kidney (HEK) cells. The current data shows several EO’s stimulating calcium influx; however, two compounds, trans-2-nonenal and geranylacetone acted directly through TRPV1. Calcium assay measurements demonstrated that the two EO’s induced calcium influxes into TRPV1-transfected HEK cells. Real-time calcium measurement results were observed where transient increases in intracellular free calcium concentrations in TRPV1-transfected HEK cells occurred. These effects were diminished in the presence of TRPV1 inhibitor peptide, SB366791, suggesting that trans-2-nonenal and geranylacetone are selective activators of TRPV1. Future investigations will be required to elucidate the intracellular signaling cascades elicited via this TRPV1 stimulation in the heart.