Cannabinoids have been used in Eastern medicine for many years as pain relievers. Δ⁹-tetrahydrocannabinol (THC), the major psychoactive compound in marijuana and hashish, has been shown to interact with two specific cannabinoid receptors: cannabinoid receptor 1 (CB1 receptor) and cannabinoid receptor 2 (CB2 receptor).¹ The cannabinoid receptors can be distinguished by their amino acid sequences, signaling mechanisms, and tissue distributions.¹ Both receptors belong to the G-protein coupled receptor (GPCR) superfamily. CB1 was shown to modulate several Ca²⁺ and K⁺ ion channels.^1,2

CB1 is primarily expressed in the central nervous system. However, expression of CB1 is also detected in the peripheral terminals, in non-neuronal peripheral tissues such as uterus, testes, spleen, as well as in cells of the immune system.^2,3

CB1 is implicated in many cellular functions such as neurotransmitter release, pain relief, cancer, and obesity.^4,5 Growth inhibition of tumor cells was demonstrated following mixed CB1/CB2 agonist treatment in both prostate and non-melanoma skin cancers.^4,5 Through their interaction with CB1, cannabinoid compounds stimulate appetite for sweets and palatable foods in particular, making CB1 an attractive therapeutic target for the treatment of obesity and eating disorders.⁶