Flavonoids and 5-Aminosalicylic Acid Inhibit the Formation of Neutrophil Extracellular Traps

Figure 4

Influence of antioxidants on NET formation as measured by SYTOXgreen fluorescence. Neutrophils were preincubated with or without antioxidants for 30 min at 37°C. In the presence of 5 μM SYTOXgreen, NET formation was induced by 20 nM PMA and assessed for 5 h at 37°C. The NET formation of (a) the flavonoids epicatechin, catechin hydrate and rutin trihydrate, (b) the vitamins ascorbic acid, tocopherol, and (c) other pharmaceutical substances melatonin, N-acetyl-L-cytseine (NAC), urea, actetylsalicylic acid (ASS), 5-aminosalicylic acid (5-ASA) was quantified by calculation of the area under the curve (AUC). Data were normalized to the sample of PMA-stimulated neutrophils without antioxidants (Med.). Data show mean ± SD from 4 ((c), melatonin), 5 ((b), (c)), 6 ((a), epicatechin, rutin trihydrate), or 8 ((a), catechin hydrate), independent experiments with 2 ((c), ASS, melatonin), 3 ((c), NAC) 4 ((a), epicatechin, rutin trihydrate), 5 ((b), (c) (urea, 5-ASA)) and 6 ((a), catechin hydrate) different donors. ^∗∗∗𝑃<0.001; ^∗∗𝑃<0.01; ^∗𝑃<0.05 as compared to the PMA stimulated medium or solvent control (Med., Solv., black column).