Jochems C et al. (2007) Role of raloxifene as a potent inhibitor of experimental postmenopausal polyarthritis and osteoporosis. Arthritis Rheum 56: 3261–3270

Estrogen is thought to protect against rheumatoid arthritis (RA), since the incidence of RA peaks at menopause and use of oral contraceptives and hormone replacement therapy are known to reduce the risk of this disease. Raloxifene is a selective estrogen receptor modulator used for prevention and treatment of postmenopausal osteoporosis. It acts as an agonist of estrogen in bone but an antagonist in other tissues and, therefore, is not associated with many of the adverse effects of hormone replacement therapy. Jochems and colleagues have, therefore, studied whether raloxifene can also be used to treat arthritis.

In a well-established mouse model of RA, prophylactic and therapeutic use of raloxifene analog LY117018 resulted in reduced disease severity, joint erosion, and cartilage destruction, and a higher rate of bone formation. LY117108 treatment also delayed arthritis onset, and reduced serum levels of interleukin 6 and spleen expression of RANKL and tumor necrosis factor mRNA, when administered before the induction of disease.

The results of this study indicate that raloxifene might prove to be a beneficial therapy for prevention and treatment of RA. The authors are planning controlled clinical trials to analyze its effects in humans.