Antihypertensive and antioxidant effects of dietary black sesame meal in pre-hypertensive humans

<p>Abstract</p> <p>Background</p> <p>It has been known that hypertension is an independent risk factor for cardiovascular disease (CVD). CVD is the major cause of morbidity and mortality in developed and developing countries. Elevation of blood pressure (BP) increases the adverse effect for cardiovascular outcomes. Prevention of increased BP plays a crucial role in a reduction of those outcomes, leading to a decrease in mortality. Therefore, the purpose of this study was to investigate the effects of dietary black sesame meal on BP and oxidative stress in individuals with prehypertension.</p> <p>Methods</p> <p>Twenty-two women and eight men (aged 49.8 ± 6.6 years) with prehypertension were randomly divided into two groups, 15 subjects per group. They ingested 2.52 g black sesame meal capsules or placebo capsules each day for 4 weeks. Blood samples were obtained after overnight fasting for measurement of plasma lipid, malondialdehyde (MDA) and vitamin E levels. Anthropometry, body composition and BP were measured before and after 4-week administration of black sesame meal or a placebo.</p> <p>Results</p> <p>The results showed that 4-week administration of black sesame meal significantly decreased systolic BP (129.3 ± 6.8 vs. 121.0 ± 9.0 mmHg, <it>P </it>< 0.05) and MDA level (1.8 ± 0.6 vs. 1.2 ± 0.6 μmol/L, <it>P </it>< 0.05), and increased vitamin E level (29.4 ± 6.0 vs. 38.2 ± 7.8 μmol/L, <it>P </it>< 0.01). In the black sesame meal group, the change in SBP tended to be positively related to the change in MDA (<it>R = 0.50, P </it>= 0.05), while the change in DBP was negatively related to the change in vitamin E (<it>R = -0.55, P </it>< 0.05). There were no correlations between changes in BP and oxidative stress in the control group.</p> <p>Conclusions</p> <p>These results suggest the possible antihypertensive effects of black sesame meal on improving antioxidant status and decreasing oxidant stress. These data may imply a beneficial effect of black sesame meal on prevention of CVD.</p

Human NAD(P)H:Quinone Oxidoreductase Type I (hNQO1) Activation of Quinone Propionic Acid Trigger Groups

NAD(P)H:quinone oxidoreductase type I (NQO1) is a target enzyme for triggered delivery of drugs at inflamed tissue and tumor sites, particularly those that challenge traditional therapies. Prodrugs, macromolecules, and molecular assemblies possessing trigger groups that can be cleaved by environmental stimuli are vehicles with the potential to yield active drug only at prescribed sites. Furthermore, quinone propionic acids (QPAs) covalently attached to prodrugs or liposome surfaces can be removed by application of a reductive trigger stimulus, such as that from NQO1; their rates of reductive activation should be tunable via QPA structure. We explored in detail the recombinant human NAD(P)H:quinone oxidoreductase type I (rhNQO1)-catalyzed NADH reduction of a family of substituted QPAs and obtained high precision kinetic parameters. It is found that small changes in QPA structure—in particular, single atom and function group substitutions on the quinone ring at R(1)—lead to significant impacts on the Michaelis constant (K(m)), maximum velocity (V(max)), catalytic constant (k(cat)), and catalytic efficiency (k(cat)/K(m)). Molecular docking simulations demonstrate that alterations in QPA structure result in large changes in QPA alignment and placement with respect to the flavin isoalloxazine ring in the active site of rhNQO1; a qualitative relationship exists between the kinetic parameters and the depth of QPA penetration into the rhNQO1 active site. From a quantitative perspective, a very good correlation is observed between log(k(cat)/K(m)) and the molecular-docking-derived distance between flavin hydride donor site and quinone hydride acceptor site in the QPAs, an observation that is in agreement with developing theories. The comprehensive kinetic and molecular modeling knowledge obtained for the interaction of recombinant human NQO1 with the quinone propionic acid analogues provides insight into the design and implementation of the QPA trigger groups for drug delivery applications