Effect of genistein and daidzein on platelet aggregation and monocyte and endothelial function

Abstract

There has been much recent interest in the cardiovascular benefits of dietary isoflavones. The aim of the present in vitro studies was to investigate potential anti-thrombogenic and antiatherogenic effects of the isoflavones genistein and daidzein in platelets, macrophages and endothelial cells. Pre-treatment with either isoflavone inhibited collagen-induced platelet aggregation in a dose-dependent manner. In a macrophage cell line (RAW 264·7) activated with interferon g plus lipopolysaccharide, both isoflavones were found to inhibit NO production and tumour necrosis factor a (TNF-a) secretion dose-dependently, but they did not affect mRNA levels for inducible nitric oxide synthase and cyclo-oxygenase-2. Both isoflavones also dose-dependently decreased monocyte chemoattractant protein-1 secretion induced by TNF-a in human umbilical vein endothelial cells. Compared with daidzein, genistein exerted greater inhibitory effects for all parameters studied. The present data contributes to our knowledge on the molecular mechanisms by which isoflavones may protect against coronary artery disease. Further studies are required to determine whether the effects of isoflavones observed in the current in vitro studies are relevant to the aetiology of coronary artery disease in vivo.

Soybean Products Consumption in the Prevention of Cardiovascular Diseases

“…Daizein, another soy flavonoid that lacks tyrosine kinase inhibitory activity also inhibited the response to collagen and the TXA2 analog, suggesting that these flavonoids inhibit platelet aggregation by competition for the TXA2 receptor (TXA2R) rather than through tyrosine kinase inhibition. These observations were confirmed by other groups (Gottstein et al 2003;Guerrero et al 2005;Guerrero et al 2007). Guerrero and colleagues suggested that this competitive binding was due to structural features of these flavonoids such as the presence of a double bond in C2-C3 and a keto group in C4.…”

Techniques for quantifying effects of dietary antioxidants on transcription factor translocation and nitric oxide production in cultured cells

“…The increase in NF-kB translocation may have been caused by such properties. We have previously shown that the reduction by genistein of induced NO production does not depend on iNOS mRNA expression (Gottstein et al, 2003), which may account for the apparently contradictory effects of genistein on NF-kB translocation and NO production. The techniques described above will allow further investigation of these phenomena and could be applied in many other studies of the effects of dietary antioxidants and their metabolites 2004) …”

The Protective Effect of the Soybean Polyphenol Genistein against Stress-Induced Gastric Mucosal Lesions in Rats, and Its Hormonal Mechanisms

“…In the present study, genistein administration resulted in decreased TNF-␣ and CINC-1 concentrations in the gastric mucosa of WIR-stressed rats. Previous reports have already demonstrated that genistein inhibits TNF-␣ production in monocytic macrophage cell lines in vitro (32) and in lipopolysaccharide-stimulated-monocytes and macrophages in vivo (33). Further, genistein inhibits tyrosine kinase, which participates in local inflamma- (34), and NF-B activity (28,35).…”