Inhibition of arachidonic acid oxidation by β-carotene, retinol and α-tocopherol

Prostaglandin and hydroxyicosatetraenoic acid (HETE) production from arachidonic acid in bovine seminal vesicles and kidney as influenced by the addition of β-carotene, retinol or α-tocopherol was studied. The major product formed was prostaglandin E₂ (approximately 85% prostaglandin E₂ of control), and its proportion decreased with increasing concentration of the additives, while the proportion of HETE increased. Prostaglandin and HETE production was considerably inhibited by β-carotene and retinol, and to a lesser extent by α-tocopherol; HETE production was inhibited less than that of prostaglandin. It appears that β-carotene, retinol and α-tocopherol influence both the cyclooxygenase and lipoxygenase pathways; this modulation of arachidonic acid oxidation by physiological compounds may have important in vivo implications.