| Human neutrophils stimulated by phorbol myristate acetate (PMA), an activator of protein kinase C, produce active oxygen by NADPH oxidase in intracellular structures. We added succinimidyl ester of dichlorodihydrofluorescein diacetate (H2DCFDA), which first emits fluorescence when oxidized with active oxygen species, to neutrophils to produce active oxygen, in order to investigate the antioxidant effects of protocatechuic acid, ferulic acid, and caffeic acid which belong to polyphenols and are widely distributed among plants. Particularly, we focused on examining whether these substances capture and eliminate active oxygen inside or outside the neutrophil cytoplasm and whether these substances inhibit NADPH oxidase. Fluorescence microscopy demonstrated... |
