Inhibition of 5-lipoxygenase activity by the natural anti-inflammatory compound aethiopinone

Abstract:

Objetive and Design: We have investigated the mechanisms of action of aethiopinone, an anti-inflammatory compound from Salvia aethiopis L. roots.¶Material and Subjects: Human neutrophils from healthy volunteers and murine peritoneal macrophages. Swiss mice were randomly divided into groups of six animals.¶Treatment: Test compounds were applied topically in the mouse ear oedema test. In the air pouch, mice received aethiopinone (0.001-0.5 μmol/pouch or 12.5-50 mg/kg p.o.).¶Methods: LTB₄ production was assayed in human neutrophils and COX-2 and iNOS activities in murine macrophages. Air pouches were induced subcutaneously in mice and injected with zymosan on the day six. Mouse ear oedema was induced by arachidonic acid. Dunnett's t-test was employed for statistical analysis.¶Results: We have observed potent inhibitory effects on human neutrophil LTB₄ production without effects on COX or NOS activities. Aethiopinone is an in vitro inhibitor of 5-LO from human neutrophils (IC₅₀ = 0.11 μM). In addition, aethiopinone reduced leukocyte accumulation and showed in vivo inhibitory activity on this enzyme.¶Conclusions: Our results indicate that inhibition of 5-LO could participate in the anti-inflammatory properties of this natural product.¶