Allosteric modulators targeting cannabinoid cb1 and cb2 receptors: Implications for drug discovery

Allosteric modulators of cannabinoid receptors hold great therapeutic potential, as they do not possess intrinsic efficacy, but instead enhance or diminish the receptor's response of orthosteric ligands allowing for the tempering of cannabinoid receptor signaling without the desensitization, tolerance and dependence. Allosteric modulators of cannabinoid receptors have numerous advantages over the orthosteric ligands such as higher receptor type selectivity, probe dependence and biased signaling, so they have a great potential to separate the therapeutic benefits from side effects own of orthosteric ligands. This review aims to give an overview of the CB1 and CB2 receptor allosteric modulators highlighting the structure-activity relationship and pharmacological profile of each classes, and their future promise.