CBD and the 5-HT1A receptor: A medicinal and pharmacological review

Cannabidiol (CBD), a phytocannabinoid, has emerged as a promising candidate for addressing a wide array of symptoms. It has the ability to bind to multiple proteins and receptors, including 5-HT1AR, transient receptor potential vanilloid 1 (TRPV1), and cannabinoid receptors. However, CBD's pharmacodynamic interaction with 5-HT1AR and its medicinal outcomes are still debated. This review explores recent literature to elucidate these questions, highlighting the neurotherapeutic outcomes of this pharmacodynamic interaction and proposing a signaling pathway underlying the mechanism by which CBD desensitizes 5-HT1AR signaling. A comprehensive survey of the literature underscores CBD's multifaceted neurotherapeutic effects, which include antidepressant, anxiolytic, neuroprotective, antipsychotic, antiemetic, anti-allodynic, anti-epileptic, anti-degenerative, and addiction-treating properties, attributable in part to its interactions with 5-HT1AR. Furthermore, evidence suggests that the pharmacodynamic interaction between CBD and 5-HT1AR is contingent upon dosage. Moreover, we propose that CBD can induce desensitization of 5-HT1AR via both homologous and heterologous mechanisms. Homologous desensitization involves the recruitment of G protein-coupled receptor kinase 2 (GRK2) and β-arrestin, leading to receptor endocytosis. In contrast, heterologous desensitization is mediated by an elevated intracellular calcium level or activation of protein kinases, such as c-Jun N-terminal kinase (JNK), through the activity of other receptors.