Role of Cannabinoids in Pain Management

It is a curious fact that we owe a great deal of our insight into pharmacological treatment of pain to the plant world [ 1 ] . Willow bark from Salix spp. led to development of aspirin and eventual elucidation of the analgesic effects of prostaglandins and their role in in fl ammation. The opium poppy ( Papaver somniferum ) provided the prototypic narcotic analgesic morphine, the fi rst alkaloid discovered, and stimulated the much later discovery of the endorphin and enkephalin systems. Similarly, the pharmacological properties of cannabis ( Cannabis sativa ) prompted the isolation of D 9 -tetrahydrocannabinol (THC), the major psychoactive ingredient in cannabis, in 1964 [ 2 ] . It is this breakthrough that subsequently prompted the more recent discovery of the body’s own cannabis-like system, the endocannabinoid system (ECS), which modulates pain under physiological conditions. Pro-nociceptive mechanisms of the endovanilloid system were similarly revealed by phytochemistry of capsaicin, the pungent ingredient in hot chile peppers ( Capsicum annuum etc.), which activates transient receptor potential vanilloid receptor-1 (TRPV1). Additional plant products such as the mints and mustards activate other TRP channels to produce their physiological effects.