Antiflammins: Anti-inflammatory activity and effect on human phospholipase A2

Abstract Two anti-inflammatory peptides (antiflammins) corresponding to a high amino acid similarity region between lipocortin I and uteroglobin were tested for their ability to inhibit purified human synovial fluid phospholipase A 2 (HSF-PLA 2 ). No inhibitory activity was observed, even at such high concentrations of peptides as 50 μM. When antiflammins were preincubated with the enzyme and/or the substrate, no HSF-PLA 2 inhibition was detected. In vivo anti-inflammatory activity of these peptides was evaluated in several experimental models of inflammation induced by carrageenan, croton-oil, oxazolone and Naja naja naja venom phospholipase A 2 (PLA 2 ). In contrast to the in vitro results, anti-inflammatory activity was observed in all tests, except when inflammation was induced by snake venom PLA 2 . Taken together, our results do not support the hypothesis that the in vivo anti-inflammatory effect of antiflammins is directly related to inhibition of PLA 2 activity.