The protective effects of incadronate on inflammation and joint destruction in established rat adjuvant arthritis.

The effects of a new generation bisphosphonate, incadronate, in established adjuvant arthritis rats were evaluated according to the arthritis index, hind paw volume, and radiological and histopathological examinations. Incadronate suppressed the radiological and histopathological changes of hind paws, as well as the joint swelling in a dose-dependent manner. In contrast, the arthritis control rats showed drastic joint inflammation, marked destruction of bone and articular cartilage. The remains of articular cartilage lost Safranin O staining, and were attached with numerous TRAP-positive multinuclear cells. Some of resorption lacunas could be seen at the cartilage matrix nearby the TRAP-positive multinuclear cells. As regards the chondroprotective effects of bisphosphonates, we speculate that it is probably concerned with the inhibition of the chondroclasts. These data indicate that bisphosphonates may be a class of effective agent that can be considered for treatment of various arthritic conditions, including human rheumatoid arthritis.