Cannabis, cannabinoids, and receptor responses

Cannabis is a legal substance in many countries today, and there is intense research on cannabinoids being undertaken globally for their health benefits and their potential to treat various diseases. Cannabinoids have been shown to interact with cannabinoid receptors, CB1 and CB2, as well as many other receptors, and there is still much to be discovered. Cannabis itself produces several cannabinoids including the most popular Δ9-tetrahydrocannabinol, cannabidiol, other major cannabinoids, as well as minor cannabinoids. These compounds are present in cannabis flowers and cannabis extracts at a significantly variable range, and their corresponding biological activities varies significantly at various receptors in our body. Polypharmacy and polypharmacology are important when considering cannabis and cannabinoids for therapeutic activities. This chapter discusses the chemistry of cannabinoids in cannabis, their receptor activities, and applications in chemistry and pharmacology for future explorations.