“Cannabis-based medicines have a number of therapeutic indications, including anti-inflammatory and analgesic effects… cannabis-based drugs have therapeutic potential in inflammatory diseases, including rheumatoid arthritis (RA) and multiple sclerosis (MS)…aim of this study was to determine whether the key elements of the endocannabinoid signalling system.. are expressed in the synovia of patients with osteoarthritis (OA) or RA… Our data predict that the cannabinoid receptor system present in the synovium may be an important therapeutic target for the treatment of pain and inflammation associated with OA and RA.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2453762/?tool=pubmed