Effect of adjuvant-induced arthritis on bone mass in rats and its prevention by non-steroid anti-inflammatory drugs (NSAIDs).

The effect of two propionic acid derived drugs, ketoprofene and butibufene, on the prevention of osteopenia due to adjuvant-induced anti-inflammatory arthritis, was studied in groups composed of 10 rats each. Another group of 10 rats was treated with a placebo and 20 non-treated rats served as controls. Once arthritis was evoked, propionic acid derived drugs were administered at equivalent doses, in the form of a local cream applied on the foot where arthritis was induced. The placebo group was treated with the cream without propionic acid derivatives. Rats were sacrificed at the end of the study and the femurs where arthritis was induced were dissected. Bone densitometry studies were conducted with double energy X-ray on these bones to calculate the bone mass. Bone mass was higher in the group treated with ketoprofene (p < 0.025) than in the butibufene and placebo-treated groups, and these 3 groups showed lower values than the control (p < 0.001). These results suggest that propionic acid derivatives can prevent the osteopenia induced by inflammation and the subsequent lack of limb use, an effect which may be related to its analgesic and/or anti-inflammatory effects. In addition, this may serve as a good model for the indirect measurement of the effectiveness of analgesic and/or non-steroid anti-inflammatory drugs in experimental animals.