A Comparative Study upon the Therapeutic Indices of Some Natural and Synthetic Anti-inflammatory Agents

OBJECTIVE(S): The aim of the present study was to compare the therapeutic indices of several agents used in treatment of inflammatory conditions which included: Vitamin E, hydro-alcoholic extracts of Glycyrrhiza glabra, Matricaria aurea, dexamethasone, piroxicam and diclofenac using Wehi-164 fibrosarcoma cells. MATERIALS AND METHODS: Cytotoxicity evaluation was based on vital dye exclusion assay. Matrix-metalloproteinases inhibition (MMPI) was assessed by gelatinase zymography method. The collected data were used to estimate the IC(50) (50% MMPI concentration), LC(50) (50% cytotoxicity concentration) and the therapeutic index (LC(50)/IC(50)). RESULTS: Among the natural anti-inflammatory agents used, M. aurea was the least toxic and the most effective inhibitor of MMP. Vitamin E not only increased MMP activity, but also was the most toxic of all the agents tested. Next in terms of toxicity to vitamin E was G. glabra. Diclofenac was more toxic than both piroxicam and dexamethasone. CONCLUSION: Findings from this study suggest that medicinal plants reputed to have anti-inflammatory properties are not equally effective and safe. In order to assess the implications of these findings, further in vitro and in vivo studies are needed.