Protective Effect on Human Lymphocytes of Some Flavonoids Isolated from Two Achillea Species

This study was conducted to elucidate the in vitro protective effect of five flavonoids [apigenin (1), apigenin-7-O-glucoside (2), centaureidin (3), jaceidin (4) and quercetin (5)] against chromosomal damage in mitogen-induced human lymphocytes. Using the Cytochalasin-B blocked micronucleus (CBMN) assay, in which the biomarker of chromosome breakage and/or chromosome loss is the elevated frequency of micronucleus (MN) in binucleated (BN) cells, the presence of flavonoid 2 in minimal concentration (3 mu g/mL) gave a 35.5% decrease M the frequency of MN when compared with control human lymphocytes. The same concentration of flavonoids 1, 3 and 4, reduced the MN frequency by 24.4%, 28.0% and 28.0%, respectively. Higher concentrations (6 mu g/mL and 10 mu g/mL) seemed less effective. Flavonoid 5 (3 mu g/mL.) induced a slight decrease in MN frequency (5%), while higher doses (6 mu g/mL and 10 mu g/mL) provoked an increase of DNA damage. The comparable values for the cytokinesis-block proliferation index (CBPI) of the tested flavonoids and positive control suggested an inhibitory effect on lymphocyte proliferation. In the DPPH scavenging assay, flavonoids 1-4 demonstrated modest activity, in a dose-dependent manner, compared with the synthetic antioxidants BHT and Trolox, while 5 exhibited comparably high antioxidative activity

Protective Effect on Human Lymphocytes of Some Flavonoids Isolated from Two Achillea Species

This study was conducted to elucidate the in vitro protective effect of five flavonoids [apigenin (1), apigenin-7-O-glucoside (2), centaureidin (3), jaceidin (4) and quercetin (5)] against chromosomal damage in mitogen-induced human lymphocytes. Using the Cytochalasin-B blocked micronucleus (CBMN) assay, in which the biomarker of chromosome breakage and/or chromosome loss is the elevated frequency of micronucleus (MN) in binucleated (BN) cells, the presence of flavonoid 2 in minimal concentration (3 mu g/mL) gave a 35.5% decrease M the frequency of MN when compared with control human lymphocytes. The same concentration of flavonoids 1, 3 and 4, reduced the MN frequency by 24.4%, 28.0% and 28.0%, respectively. Higher concentrations (6 mu g/mL and 10 mu g/mL) seemed less effective. Flavonoid 5 (3 mu g/mL.) induced a slight decrease in MN frequency (5%), while higher doses (6 mu g/mL and 10 mu g/mL) provoked an increase of DNA damage. The comparable values for the cytokinesis-block proliferation index (CBPI) of the tested flavonoids and positive control suggested an inhibitory effect on lymphocyte proliferation. In the DPPH scavenging assay, flavonoids 1-4 demonstrated modest activity, in a dose-dependent manner, compared with the synthetic antioxidants BHT and Trolox, while 5 exhibited comparably high antioxidative activity

Protective Effect on Human Lymphocytes of Some Flavonoids Isolated from Two Achillea Species

This study was conducted to elucidate the in vitro protective effect of five flavonoids [apigenin (1), apigenin-7-O-glucoside (2), centaureidin (3), jaceidin (4) and quercetin (5)] against chromosomal damage in mitogen-induced human lymphocytes. Using the Cytochalasin-B blocked micronucleus (CBMN) assay, in which the biomarker of chromosome breakage and/or chromosome loss is the elevated frequency of micronucleus (MN) in binucleated (BN) cells, the presence of flavonoid 2 in minimal concentration (3 mu g/mL) gave a 35.5% decrease M the frequency of MN when compared with control human lymphocytes. The same concentration of flavonoids 1, 3 and 4, reduced the MN frequency by 24.4%, 28.0% and 28.0%, respectively. Higher concentrations (6 mu g/mL and 10 mu g/mL) seemed less effective. Flavonoid 5 (3 mu g/mL.) induced a slight decrease in MN frequency (5%), while higher doses (6 mu g/mL and 10 mu g/mL) provoked an increase of DNA damage. The comparable values for the cytokinesis-block proliferation index (CBPI) of the tested flavonoids and positive control suggested an inhibitory effect on lymphocyte proliferation. In the DPPH scavenging assay, flavonoids 1-4 demonstrated modest activity, in a dose-dependent manner, compared with the synthetic antioxidants BHT and Trolox, while 5 exhibited comparably high antioxidative activity

Radioprotective effects of Gentianella austriaca fractions and polyphenolic constituents in human lymphocytes

The aim of this study was to identify active principles of Gentianella austriaca responsible for the reduction of the incidence of micronuclei in irradiated lymphocytes in vitro. The radioprotective effects of ether (EF) and methanolic (MeF) fractions, water-soluble xanthones demethylbellidifolin (1), demethylbellidifolin 8-O-glucoside (2), bellidifolin 8-O-glucoside (3), and flavonoid swertisin (4) against chromosomal damage induced by gamma-rays were determined using the micronucleus test. EF and MeF showed better protection in treatment of human lymphocytes after gamma-irradiation than did isolated compounds. Among the isolated compounds, the effectivenessin reduction of the frequency of micronuclei followed the order 4 GT 3 GT 2 GT 1. The anti-lipoperoxidant activity was in the order 2 GT 4 GT 1, while 3 slightly increased the level of malondialdehyde. In addition, the effectiveness in induction of apoptosis followed the order, 3 GT 2 GT 4, while 1 had no proapoptotic effect. These results suggest that the antioxidative properties of the polyphenols tested may contribute to the radioprotective effects of G. austriaca