We asked John Karapelou, a noted illustrator, to visualize CB1 and CB2 receptor expression in the skin. Nice work!
Skin is our largest organ. Our every movement relies on skin to stretch and regain its shape and size. Our skin's endocannabinoid system's function is to keep skin in top condition. Healthy skin acts as an effective barrier against the environment.
Scientists only discovered the endocannabinoid system (ECS) within the skin during the last 25 years. Most recent research investigations are in the emerging field of cannabis based cosmetics. Some research involves cannabidiol (CBD), derived from hemp, as CBD might have been the easiest cannabinoid to acquire for research purposes. Other cannabinoids being considered for topical application are tetrahydrocannabinol (THC) and cannabigerol (CBG).
Cannabinoid receptors allow different body systems to communicate. Skin cannabinoid (CB) receptors, at the ends of sensory nerves, in hair follicles, immune cells, mast cells, sweat glands, sebaceous glands and epidermis, allow for sensory perceptions of touch, pressure, vibration, temperature, pain, and itch to travel the endocannabinoid system's pathways.
Curious about rubbing cannabis on your skin? Understand how topicals might work. Learn about topical oils and patches. Read a case study. Part of the Cannabis Resource Library by The Cannabis Access Resource and Education Center.
Researchers found topically applied THC can effectively reduce contact allergic inflammation in mice by decreasing keratinocyte-derived pro-inflammatory mediators that orchestrate myeloid immune cell infiltration independent of CB1 /2 receptors.
The skin's endocannabinoid system is activated during a contact allergic outbreak. Stimulation of skin's CB receptors reduces the inflammation. Scientists, working with mice, found that topical application of D9-THC reduced allergic inflammation points. [PDF 4p]
"Just as THC is believed to protect the marijuana plants from pathogens, our own cannabinoids may be necessary for us to maintain healthy skin and to protect us from pathogens." --Dr. Gerald Weissmann.
According to researchers at University of Colorado Anschutz Medical Campus, cannabinoids have anti-inflammatory properties that could make them useful in the treatment skin disease systems, such as pain and itch. The study was based on laboratory models and large-scale clinical trials have not been performed.
"CB1 and CB2 immunoreactivity were observed in cutaneous nerve fibre bundles, mast cells, macrophages, epidermal keratinocytes, and the epithelial cells of hair follicles, sebocytes and eccrine sweat glands. In epidermal keratinocytes, hair follicle and sebaceous glands, CB1 and CB2 were distributed in a complementary fashion. Double-immunostaining with an anti-CGRP antibody suggested the presence of cannabinoid receptors on small afferent peptidergic nerves." --Sonja Ständer, Martin Schmelz, Dieter Metze, Thomas Luger, Roman Rukwied.
Andreas Voss, Katharina Witt, Tobias Kaschowitz, Wolf Poitz, Andreas Ebert, Patrik Roser and Karl-Jürgen Bär, eNose, provide evidence that their portable and fast-working eNose system successfully analyzes human skin odour for the presence THC metabolites.
Mice, six hours after being inflicted with skin incisions, increased CB1 receptors at the injury site. CB1 expressing cells numbers peaked at five days post-injury and reduced to baseline levels within two weeks.
Study: Expression of Cannabinoid Receptor 1 during Mice Skin Incised Wound Healing Course
Authors: Zhao ZB, Guan DW, Liu WW, Wang T, Fan YY, Cheng ZH, Zheng JL, Hu GY.