(-)-α-Pinene is a monoterpene and shows sleep enhancing property through a direct binding to GABAA-benzodiazepine (BZD) receptors by acting as a partial modulator at the BZD binding site[1].
(-)-α-pinene enhances the quantity of non-rapid eye movement sleep (NREMS) without affecting the intensity of NREMS by prolonging GABAergic synaptic transmission, acting as a partial modulator of GABAA-BZD receptors and directly binding to the BZD binding site of GABAA receptor[1].
[1]. Yang H, et al. α-Pinene, a Major Constituent of Pine Tree Oils, Enhances Non-Rapid Eye Movement Sleep in Micethrough GABAA-benzodiazepine Receptors.