Therapeutic Effects of Non-Euphorigenic Cannabis Extracts in Osteoarthritis

Osteoarthritis (OA) is disabling and degenerative disease of the joints that is clinically characterized by pain and loss of function. With no disease-modifying treatment available, current therapies aim at pain management but are of limited efficacy. Cannabis products, specifically cannabinoids, are widely used to control pain and inflammation in many diseases with no scientific evidence demonstrating their efficacy in OA. We investigated the effects of non-euphorigenic cannabis extracts, CBD oil and cannabigerol oil (CBG oil), on pain and disease progression in OA mice. Twelve-week-old male C57BL/6J mice received either sham or destabilization of the medial meniscus (DMM) surgery. DMM mice were treated with vehicle, CBD oil, or CBG oil. The gait of DMM mice was impaired as early as 2 weeks following surgery and continued deteriorating until week 8, which was restored by CBD oil and CBG oil treatments throughout the disease course. Mechanical allodynia developed in DMM mice, however, was not ameliorated by any of the treatments. On the other hand, both CBD oil and CBG oil ameliorated cold allodynia. In open field test, both oil treatments normalized changes in the locomotor activity of DMM mice. CBD oil and CBG oil treatments significantly reduced synovitis in DMM mice. Only CBG oil reduced cartilage degeneration, chondrocyte loss, and matrix metalloproteinase 13 expression, with a significant increase in the number of anabolic chondrocytes. Subchondral bone remodeling found in vehicle-treated DMM mice was not ameliorated by either CBD or CBG oil. Our results show evidence for the therapeutic efficacy of CBD oil and CBG oil, where both oils ameliorate pain and inflammation, and improve gait and locomotor activity in OA mice, representing clinical pain and function. Importantly, only CBG oil is chondroprotective, which may provide superior efficacy in future studies in OA patients.