Panax notoginseng saponins alleviate osteoporosis and joint destruction in rabbits with antigen-induced arthritis

Although a number of anti-rheumatic drugs and biologics may be used to alleviate the symptoms of rheumatoid arthritis (RA), these compounds have been associated with bone loss and joint destruction; thus, alternative treatment approaches are required. In the present study, various plant extracts were evaluated for their capacity to inhibit joint destruction, and Panax notoginseng saponins (PNS), obtained from the Traditional Chinese Medicine Panax notoginseng, was identified as such a compound. Therefore, a rabbit antigen-induced arthritis (AIA) model was generated by immunization with ovalbumin in Freund's complete adjuvant, followed by treatment with PNS for 3 months. The morphology of the quadriceps femoris muscle, cartilage chondrocytes and skeletal elements was histologically observed by transmission electron microscopy (TEM), as well as micro-computed tomography. The results revealed that PNS significantly reduced the histopathological alterations associated with arthritic muscular atrophy and inflammation. In addition, TEM demonstrated that PNS protected chondrocytes from RA-associated damage. Furthermore, the bone density and microarchitecture in rabbits treated with PNS were markedly improved compared with those of the model group. Collectively, these data indicated that treatment with PNS may relieve osteoporosis and prevent joint and bone destruction in AIA.