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

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-1ß, 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-1ß 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.

In vitro and in vivo assessment of the anti-inflammatory activity of olive leaf extract in rats.

Inflammation is a complex and crucial process that protects the body against pathogens. Here in our study, we propose to scientifically justify the anti-inflammatory activity of olive leaf (OL). Initially, we ensured the safety of olive leaf extract (OLE) through acute oral administration of graded doses up to 4 g\kg in Wistar rats. Thus, the extract was considered generally safe. We also evaluated the ability of the extract to reduce carrageenan-induced rat paw edema. Compared to diclofenac sodium (10 mg/kg PO), OLE showed significant (P < 0.05) anti-inflammatory activity, showing the maximum inhibition percentage at the fifth hour of measurement at 42.31% and 46.99%, at doses of 200 and 400 m/kg, respectively, compared to 63.81% for the standard drug. To elucidate the potential mechanism, we measured TNF, IL-1, COX-2 and NO inside the paw tissue. Interestingly, OLE at all tested doses reduced the concentration of TNF and IL-1 to a level that was lower than that obtained by the standard drug. Additionally, OLE at the dose of 400 mg/kg reduced the levels of COX-2 and NO inside the paw tissue to a level that was statistically equivalent to the level observed in the normal control group. Finally, olive leaf extract at doses of 100, 200 and 400 mg/kg doses significantly (P < 0.05) inhibited the heat-induced hemolysis of RBCs membrane by 25.62, 57.40 and 73.88%, respectively, compared to 83.89% produced by aspirin. Consequently, we concluded that olive leaf extract has a significant anti-inflammatory activity through the reduction of TNF, IL-1, COX-2 and NO.