Figure 5: The effect of Clinacanthus nutans (a) 100% ethanolic, (b) 70% and (c) 50% aqueous ethanolic, and (d) 100% aqueous extracts on the release of TNF-α from IgE-mediated degranulated mast cells. Data were presented as mean ± standard error of the mean of three independent experiments in triplicate. All ethanolic and aqueous extracts did not inhibit the release of tumour necrosis factor-alpha even at 1000 μg/ml (ethanolic) and 7 mg/ml (aqueous). Ketotifen fumarate (K), a clinically used mast cell stabilizer at 300 μM showed significant inhibition in all experiments. ***P ≤ 0.001 significantly different from dinitrophenyl-bovine serum albumin -challenged control.