Arthritis is marked by painful inflammation of one or more joints. With known effects of cannabinoids in the reduction of pain and inflammation and in bone formation, cannabinoids offer great potential in the treatment of arthritis. However, to date, no large-scale, double-blind clinical trial has proven this potential.
In mice genetically deficient for CB2, experimentally induced osteoarthritis was significantly worse than in control mice (Sophocleous et al., 2015). In addition, naturally occurring osteoarthritis was more severe in CB2 deficient mice than in controls.
In mice with collagen-induced Arthritis 5 mg/kg/day i.p. or 25 mg/kg/day oral effectively blocked disease progression and suppressed joint damage, lymphocyte proliferation and IFNγ and TNF expression (Malfait et al., 2000).
Malfait, A.M., Gallily, R., Sumariwalla, P.F., Malik, A.S., Andreakos, E., Mechoulam, R., and Feldmann, M. (2000). The nonpsychoactive cannabis constituent cannabidiol is an oral anti-arthritic therapeutic in murine collagen-induced Arthritis. Proc. Natl. Acad. Sci. U. S. A. 97, 9561–9566.
Sophocleous, A., Börjesson, A.E., Salter, D.M., and Ralston, S.H. (2015). The type 2 cannabinoid receptor regulates susceptibility to osteoarthritis in mice. Osteoarthr. Cartil. OARS Osteoarthr. Res. Soc.
In another study, inhibition of FAAH (which should increase endocannabinoid levels) failed to reduce pain in arthritis (Huggins et al., 2012). More and larger studies are required to assess the therapeutic potential of cannabinoids in arthritis.
Blake, D.R., Robson, P., Ho, M., Jubb, R.W., and McCabe, C.S. (2006). Preliminary assessment of the efficacy, tolerability and safety of a cannabis-based medicine (Sativex) in the treatment of pain caused by rheumatoid arthritis. Rheumatology 45, 50–52.
Huggins, J.P., Smart, T.S., Langman, S., Taylor, L., and Young, T. (2012). An efficient randomised, placebo-controlled clinical trial with the irreversible fatty acid amide hydrolase-1 inhibitor PF-04457845, which modulates endocannabinoids but fails to induce effective analgesia in patients with pain due to osteoarthritis of the knee. pain 153, 1837–1846.