Effect of structurally related flavones/isoflavones on hydrogen peroxide production and oxidative DNA damage in phorbol ester‐stimulated HL‐60 cells

Abstract

We have examined the antioxidant properties of structurally related flavones/isoflavones in 12-O-tetradecanoylphorbol-13-acetate (TPA)-stimulated HL-60 cells. In the presence of 1.3% dimethyl sulfoxide in the medium for seven days, promyelocytic HL-60 cells were differentiated into neutrophil-like cells possessing phagocytic properties and the capacity to generate H2O2 on TPA stimulation. The effects of five selected flavones/isoflavones on the formation of H2O2 and 8-hydroxy-2'-deoxyguanosine (8-OHdG) were examined in TPA-stimulated HL-60 cells. The results indicated that genistein was the most potent inhibitor of H2O2 production by TPA-stimulated HL-60 cells, followed by apigenin and daidzein, whereas prunectin and biochanin A exhibited no effect. This inhibitory effect correlates well with the scavenging capacity of H2O2 by these flavones/isoflavones in an in vitro system. The formation of 8-OHdG in cellular DNA of HL-60 cells was induced by TPA and further enhanced by the addition of FeCl2 to the medium. Most flavones/isoflavones significantly inhibited TPA + FeCl2-induced 8-OHdG formation in HL-60 cells, with genistein being the most potent quencher. The inhibition of H2O2 production and 8-OHdG formation by these structurally related flavones/isoflavones may contribute to their chemopreventive potentials against human cancers.

Effect of Different Dietary Protein Composition on Skeletal Muscle Atrophy by Suspension Hypokinesia/Hypodynamia in Rats.

“…Soy isoflavones have been shown to exhibit antioxidant effects in vitro and in vivo by the direct free radical quenching ability (45,46). Genistein and daidzein have also been known to prevent 8-hydroxy-2'-deoxyguano sine formation in cells and DNA exposed to oxidants (47). So SPI might reduce oxidative stress and apoptotic cell death in the muscle, though this was not deter mined in the present study.…”

Genistein supplementation to the quail: Effects on egg production and egg yolk genistein, daidzein, and lipid peroxidation levels

“…They also reported that the isoflavones, including equol, distributed mostly (95%) in the high-density fraction of blood serum and more (65%) in the granule fraction of egg yolk. Soy isoflavones have been show to increase in vivo production of superoxide dismutase, a powerful antioxidant that quenches superoxide radicals (Cai and Wei, 1996) and prevent 8-hydroxy-2′-deoxyguanosine formation in cells and DNA exposed to oxidants (Giles and Wei, 1997), and oxidative DNA damage was decreased in men consuming 1 L of soy milk daily for 4 wk (Mitchell and Collins, 1999). In the present study, yolk MDA level in Figure 2.…”

Inhibitory Effect of Isoflavones on Peroxynitrite-mediated Low-density Lipoprotein Oxidation

“…of the B ring of the iso‰avone in the presence of either one or two hydroxyl groups in the A ring of the iso‰avone molecule. 28,29) Nitrotyrosine is a useful marker for peroxynitrite detection, since tyrosine residues are readily nitrated by peroxynitrite, and it has been observed in many pathological cases including human atherosclerosis. 30) Findings from the present studies indicate that genistein, daidzein, and their glucosidic compounds, genistin and daidzin, have the potential ability to dose-dependently prevent tyrosine nitration by peroxynitrite (Fig.…”