1.
Urinary (1)H-NMR metabonomics study on intervention effects of soya milk in Africans.
Ogegbo, OL, Dissanyake, W, Crowder, J, Asekun, O, Familoni, O, Branford-White, CJ, Annie Bligh, SW
Phytotherapy research : PTR. 2012;(1):127-35
Abstract
Metabonomics is an important tool in understanding the toxicological or therapeutic effects of interventions by analysing metabolic profiles and interpreting complex multi-dimensional spectroscopic/spectrometric data using multivariate data analysis. The objectives of this study were to evaluate the metabolic changes following a short-term 5 day soya milk intervention, and to investigate factors that influence soy-phytoestrogen metabolism focused on Africans based in either UK or Nigeria. (1)H-NMR metabonomics was applied to analyse urine samples collected at four phases I-IV (pre, days 3 and 5, and post) of the soy-intervention from African volunteers (n = 40 in total). Individual proton NMR spectra were visually and statistically assessed using multivariate analyses (MVA): principal component analysis (PCA) and (orthogonal-) partial-least square-discriminant analysis ((O-) PLS-DA). In addition, 22 endogenous metabolites were quantified using a Chenomx NMR suite. The results showed the levels of analysed endogenous metabolites (creatinine adjusted) present ranged from 4 µM to 12 mM with large inter-subject variances in acetate, acetone, lactate and trimethylamine. The MVA results showed high inter-individuality and sampling variances based on PCA score plots, and demonstrated soy metabolism to be significantly influenced by location and gender by both PLS-DA and O-PLS-DA.
2.
Acute responses to phytoestrogens in small arteries from men with coronary heart disease.
Cruz, MN, Luksha, L, Logman, H, Poston, L, Agewall, S, Kublickiene, K
American journal of physiology. Heart and circulatory physiology. 2006;(5):H1969-75
Abstract
The aim of this study was to investigate acute vasodilator responses to phytoestrogens and selective estrogen receptor-alpha (ERalpha) agonist in isolated small arteries from men with established coronary heart disease (CHD) and with a history of myocardial infarction versus healthy male control subjects. As to methodology, small arteries obtained from subcutaneous fat biopsies and mounted on a wire myograph were preconstricted with norepinephrine, and dilator responses to increasing nanomolar-micromolar concentrations of the phytoestrogens resveratrol and genistein (predominantly ERbeta agonists) and to propyl-[1H]-pyrazole-1,3,5-triyl-trisplenol (PPT, a selective ERalpha agonist) were determined. These were compared with responses to reference compound 17beta-estradiol (17beta-E2). Concentration-response curves were constructed before and after nitric oxide (NO) synthase inhibition with Nomega-nitro-L-arginine methyl ester. As a result, relaxation induced by the investigated compounds was similar in men with CHD and control men, but in both groups PPT and genistein-induced relaxation was greater than that of resveratrol and 17beta-E2. NO contributed to both phytoestrogens and PPT-induced relaxation but not to 17beta-E2 responses in arteries from control men. This NO-mediated component of relaxation was absent in arteries from men with established CHD. In conclusion, phytoestrogens, at concentrations achievable by ingestion of phytoestrogen-rich food products, evoke dilatation ex vivo of small peripheral arteries from normal men and those with established CHD. The contribution of NO to dilatory responses by these compounds is pertinent to arteries from control males, whereas other NO-independent dilatory mechanism(s) are involved in arteries from CHD.