Figure 2.

Crude extract (a) and Hexane (c) and ethylacetate (b) fractions as well as the caffeic acid (f) and semi-purified fractions, ER 2.4 (d) and ER 2.7 (e), thereof exhibited significant inhibition of caspase-1 in THP-1 derived macrophages. Phorbol Myristate Acetate (PMA)-differentiated cells were pretreated by corresponding compounds for 1 h, and then primed by Lipopolysaccharide (LPS) (1 µg/mL) for 3 h. Cells were then stimulated by ATP (5 mM) for additional 1 h. The supernatants were harvested and kept at −70 °C before analysis. Then, 50 µL of the culture supernatant were used to determine the caspase-1 activity using Caspase-Glo 1 inflammasome assay (Promega Co., Madison, WI, USA). The results are presented as the mean ± SD from independent experiments (n = 2), each done in triplicate. A one-way ANOVA, followed by Benforroni’s multiple comparison test, was used to compare the sample groups. *** means Caspase-1 fold activation changes with a p < 0.0001.