LIPOXYGENASE INHIBITION AND ANTIOXIDANT PROPERTIES OF PROTOBERBERINE AND APORPHINE ALKALOIDS ISOLATED FROM MAHONIA-AQUIFOLIUM

Products of lipoxygenase metabolism play a role in the pathogenesis of psoriasis. Four protoberberine alkaloids, berberine, oxyberberine, ja trorrhizine, columbamine, and two aporphine alkaloids, magnoflorine, a nd corytuberine, isolated from Mahonia aquifolium, were tested for lip oxygenase inhibition. Oxyberberine, corytuberine, and columbamine were the most potent lipoxygenase inhibitors tested, whereas berberine and magnoflorine exhibited only low potencies. A strong linear correlatio n (r = 0.866) between lipoxygenase inhibition and lipid antioxidant pr operties of these compounds was found. These data suggest that the mec hanism of lipoxygenase inhibition by these alkaloids may be linked to the inhibition of lipids hydroperoxide substrate accumulation. Inhibit ion of lipoxygenase by these compounds may contribute to the therapeut ic effect of M. aquifolium extracts in the treatment of psoriasis.