Involvement of TNFα, IL-1β, COX-2 and NO in the anti-inflammatory activity of Tamarix aphylla in Wistar albino rats: an in-vivo and in-vitro study

Abstract Background With the emergence of many side effects from synthetic drugs, there is an urgent need to find a natural alternative to these products. Therefore, our primary aim was to evaluate the anti-inflammatory activity of Tamarix aphylla (TA) and investigate the potential mechanism underlying this action. Methods Initially, to ensure the safety of the extract and for dose selection, we performed an acute oral toxicity Assay through the oral administration of graded doses up to 4 g\kg in Wistar rats. then, we used the carrageenan-induced edema model to elucidate the anti-inflammatory activity. Using specific ELISA kits, we measured the levels of TNF-α, IL-1β, COX-2 and NO inside the inflamed paw tissue. Finally, for the in-vitro anti-inflammatory experiment, we used the erythrocyte membrane stability test. Results Based on the acute oral toxicity assay, T. aphylla was considered generally safe and three different doses of 100, 200, and 400 mg/kg were chosen for further experiments. Additionally, TA expressed a significant ( P < 0.05) anti-inflammatory activity, showing the maximum inhibition percentage at the fifth hour of measurement at 53.47% and 70.06%, at doses of 200 and 400 mg/kg respectively, compared to 63.81% for the standard drug. Similarly, we found that TA effectively reduced the levels of TNF-α and IL-1β at all tested doses (100-200-400 mg/kg) to a greater extent than the standard drug. Moreover, at 400 mg/kg, TA was able to significantly lower the levels of COX-2 and NO inside the inflamed tissue to a level comparable ( P < 0.05) with that measured inside the paw tissue of normal rats. Finally, Tamarix aphylla at 100, 200 and 400 mg/kg doses significantly ( P < 0.05) inhibited the heat-induced hemolysis of RBCs membrane by 67.78, 74.82 and 82.08%, respectively, compared to 83.89% produced by Aspirin. Conclusion T. aphylla produced a significant ( P < 0.05) anti-inflammatory activity compared to the standard drugs either through the reduction of pro-inflammatory mediators or the protection of the lysosomal membrane.