Evaluation of immunomodulatory activity of tenoxicam in mice

Purpose: The present study was conducted to evaluate the effect of tenoxicam on cellular and humoral immunity. Methods: Tenoxicam (2.5 - 10mg/kg) was administered at three different doses to three groups of mice and the cellular immune responses were studied using delayed hypersensitivity response (DTH) and cyclophosphamide-induced neutropenia while the humoral immune response was evaluated using hemagglutination test and mice mortality ratio. Normal saline and cyclophosphamide were used as negative and positive controls, respectively. Results: DTH assay resulted in a significant reduction in skin thickness (p < 0.05) for tenoxicam treated groups when compared to the negative control group at 24 h, 48 h and 72 h after administration of challenging dose of dinitrochlorobenzene (DNCB). Cyclophoshamide induced neutropenia showed a significant percentage reduction in total leukocyte count (TLC) and differential leukocyte count (DLC) i.e. lymphocytes and neutrophils (p< 0.05), but an increase in monocytes in all the treatment groups in the following order: 10 mg>5 mg >2.5 mg> negative control group. A dose dependent reduction response was observed (p< 0.05) in haemagglutination assay (HA). In mice lethality test mortality ratios of 2.5 mg, 5 mg, 10 mg tenoxicam were 60 %, 80% and 100 %, respectively, compared to 20 % and 100 % for normal saline group and cyclophosphamide, respectively. Conclusion: The results suggest that tenoxicam suppresses both cellular and humoral immunity in mice.