Figure 2. Ginger blocks PDE activity and increases cAMP levels.

(A and B) Human neutrophils were treated with the solubilized ginger extract (10 μg/mL). Some samples were additionally treated with a synthetic PDE4 inhibitor (rolipram, 0.1 μM) or an adenylate cyclase activator (forskolin, 100 μM) as indicated. PDE activity (A) and cAMP levels (B) were then measured with kits as described in Methods. (C) Neutrophils were treated with APS IgG (10 μg/mL) in the presence or absence of a solubilized ginger extract (10 μg/mL) or a PKA inhibitor (KT 5720, 10 μM). NETosis was quantified by measuring the enzymatic activity of nuclease-liberated MPO. For all panels, mean and SEM are presented for n = 3–4 independent experiments; **P < 0.01, ***P < 0.001, and ****P < 0.0001 by 1-way ANOVA corrected with Dunnett’s test.