Cannabinoid receptor type 2( CB2 R),a member of the G protein-coupled receptor( GPCR) superfamily,has a variety of biological activities,such as regulating pain response,resisting inflammation and fibrosis,and mediating bone metabolism. Some CB2 R regulators exhibit a good regulatory effect on bone metabolism. Cannabinoids in Cannabis sativa can cause psychoactive effects despite various pharmacological actions they exerted by targeting CB2 R. Therefore,it is of great significance to discover CB2 R regulators in non-Cannabis plants for finding new lead compounds without psychoactive effects and elucidating the action mechanism of plant drugs. The present study clarifies the discovery,structure,and physiological functions of CB2 R,especially its regulatory effects on bone metabolism,summarized CB2 R regulators extracted from non-Cannabis plants,and systematically analyzes the regulatory effects of CB2 R regulators on bone metabolism in animals,osteoblasts,and osteoclasts,to provide a scientific basis for the discovery of new CB2 R regulators and the development of anti-osteoporotic drugs.
Keywords: bone metabolism; cannabinoid receptor type 2(CB2R); medicinal plants; regulators; research progress.