PHARMACOLOGICAL ACTIVITY OF PHENYLPROPANOIDS OF THE MISTLETOE, VISCUM-ALBUM L., HOST - PYRUS CAUCASICA FED

Although a great number of compounds have been isolated from Viscum al bum (mistletoe, Viscaceae), none of them could be clearly shown to pos sess the established hypotensive, vasodilator, cardiotonic and antitum or activity of alcoholic preparations. In the course of our investigat ion of Armenian mistletoe Viscum album, host: Pyrus caucasica, which h as been used in Armenian traditional medicine for the treatment of car diovascular diseases and for stimulation of the immune system, four ph enylpropanoid glycosides were isolated from EtOH-extract: coniferyl al cohol 4-O-beta-D-glucopyranoside (coniferin), syringenin 4-O-beta-D-gl ucopyranoside (syringin), and coniferylalcohol- and syringenin 4-O-bet a-D-apiofuranosyl (1-->2)-beta-D-glucopyranosides. The structures were established on the basis of the spectral and chemical data. All subst ances inhibited ADP-induced platelet aggregation, and the apiosyldigly cosides only inhibited leukotriene B-4 release from TPA and calcium io nophore A-23187 stimulated human granulocytes. It is suggested that an antitumoral effect of ethanolic extract of Viscum album could be asso ciated with the inhibition of protein kinase C (PKC).