TOTAL ANTIOXIDATIVE ACTIVITY OF EVENING PRIMROSE (OENOTHERA-PARADOXA)CAKE EXTRACT MEASURED IN-VITRO BY LIPOSOME MODEL AND MURINE L1210 CELLS

The antioxidative effects of evening primrose seeds extract were inves tigated in vitro. The oil-free cake from evening primrose seeds was ex tracted with two solvents: water and acetone-water (7:3) mixture. Ther e were various contents of phenolic compounds in these extracts (580 a nd 180 mg/g of acetone-water and water extracts, respectively; express ed in D-catechin). Acetone-water extract was separated into five fract ions according to their absorbance readings at 350 nn using a Sephadex LH-20 column. Collected fractions had maximum absorptions of their UV spectra in a broad range between 278 and 286 nm (except fraction 1), which indicated that flavonoids predominated in the phenolic compounds of evening primrose. Absorption at 325 nm for fraction 1 indicated th e presence of phenolic acid in that extract. PC (L-alpha-phosphatidylc holine) liposome system and leukemic L1210 murine cells were used to e valuate the antioxidative activity of extracts and their fractions. In these systems the oxidation process was stimulated by addition of AAP H [2,2'-azobis(2-amidinopropane) dihydrochloride]. Extract with aceton e:water had the highest antioxidative activity measured by the PC oxid ation to PC-OOH (hydroxyperoxidephosphatidylcholine). Also the same ex tract in the concentration range from 17.5 to 175 ng/mL significantly inhibited peroxidation of cell membranes expressed by TEARS formation in cell cultures.