Rational Design, Synthesis, and Evaluation of Fluorescent CB₂ Receptor Ligands for Live-Cell Imaging: A Comprehensive...

The cannabinoid receptors CB₁ and CB₂ are class A G protein-coupled receptors (GPCRs) that are activated via endogenous lipids called endocannabinoids. The endocannabinoid system (ECS) plays a critical role in the regulation of several physiological states and a wide range of diseases. In recent years, drug discovery approaches targeting the cannabinoid type 2 receptor (CB₂R) have gained prominence. Particular attention has been given to selective agonists targeting the CB₂ receptors to circumvent the neuropsychotropic side effects associated with CB₁ receptors. The pharmacological modulation of CB₂R holds therapeutic promise for various diseases, such as inflammatory disorders and immunological conditions, as well as pain management and cancer treatment. Recently, the utilization of fluorescent probes has emerged as a valuable technique for investigating the interactions between ligands and proteins at an exceptional level of spatial and temporal precision. In this review, we aim to examine the progress made in the development of fluorescent probes targeting CB₂ receptors and highlight their significance in facilitating the successful clinical translation of CB₂R-based therapies.