Alcoholic extracts of the antipsoriatic Mahonia aquifolium drug which were analysed for the irqualitative and quantitative alkaloid content, showed an in vitro inhibiting effect on cyclooxygenase (CO) of sheep seminal vesicles and 5-lipoxygenase (5-LO) of porcine leucocytes. The same extracts exhibited also immunostimulating activities in two phagocytosis assays. In contrast the major alkaloids of Mahonia aquifolium extracts berberine, palmatine, magnoflorine andjatrorrhizine were found to be inactive at all in both anti-inflammatory assays, suggesting adifferent mechanism of action for the alkaloids or further not yet detected compounds in the extract.
Phytopreparations of Mahonia aquifolium (Pursh) Hutt.have been used orally in American folk medicine orally especially for the treatment of various skin diseases (Duke1985). In Europe a tincture has been introduced into homoeopathy as a remedy against psoriasis (Schindler 1955, BGA-Monography 1987). Patient studies performed with aMahonia extract containing ointment! revealed an anticell-proliferative and antiphlogistic effect after long term therapy.
Although various protoberberine-, benzylisoquinoline- and aporphine-alkaloids such as berberine, jatrorrhizine, palmatine, berbamine, oxyacanthine, and magnoflorine have been isolated from the drug (Kostalova et aI., 1981; Slaviket aI., 1985; Kostalovaet aI., 1986) it was unknown to which extent and by which exact mechanism of action theMahonia alkaloids are involved in the antipsoriatic activity of the drug. It was only established that berberine interferes with DNA synthesis and by this exerts an antiproliferative effect.