Tenidap, a new anti-inflammatory
drug, is presently undergoing clinical studies as a treatment for
rheumatoid arthritis (RA). Early pilot work has shown it to be of some benefit.
Tenidap is a dual inhibitor of
cyclo-oxygenase and
5-lipoxygenase enzymes. It has also been shown to modify white blood cell behaviour such as
interleukin-1 production, monocyte differentiation and neutrophil degranulation. As
free radicals (FRs) have been implicated in the pathogenesis of RA, we used an in vitro assay system developed by Misra and Fridovich to assess if
tenidap has FR scavenging effects. Our study shows, for the first time, that
tenidap has general FR scavenging effects although no effect on the
superoxide anion (O2.-) could be demonstrated. This effect occurred in a dose-dependent manner at concentrations above 20 mug/ml (p < 0.005, Mann-Whitney U-test). As the therapeutic range of
tenidap in serum is between 15 and 30 mug/ml such FR scavenging activity may be clinically relevant in the treatment of RA. Ex vivo confirmation of this possibility is underway.