Effects of phenolic acid esters and amides on stimulus-induced reactive oxygen species production in human neutrophils

Phenolic acids and their derivatives are widely distributed in plants. A series of phenolic acid esters and amides have been synthesized. We determined the effects of phenolic acid derivatives on antiinflammatory activity against phorbol 12-myristate 13-acetate (PMA) and N-formyl-methionyl-leucyl-phenylalanine (fMLP)-induced production of superoxide anion, an inflammatory mediator produced by neutrophils. When the cells were preincubated with phenolic acids and their derivatives, the superoxide generation induced by fMLP (1.0 μmol/l) and PMA (0.16 μmol/l) was inhibited to various degrees with compounds 1, 2 and 4 significantly suppressing such generation in a concentration-dependent manner. Phenolic acid derivatives may exert their antiinflammatory action through inhibiting superoxide generation.