New insights on effects of a dietary supplement on oxidative and nitrosative stress in humans.

The research community is generally agreed that maintenance of healthy levels of free radicals and related oxidants are important for good health. However, utilization of the "redox stress hypothesis" can provide us with concrete nutritional targets in order to better support and maintain "optimal health." Following this hypothesis we performed a crossover, double-blind, placebo-controlled, single-dose study on the effects of SPECTRA™, a dietary supplement, on oxidative stress markers (OSM) in human participants (n = 22). The measurement of OSM (ex vivo intra- and extracellular formation of reactive oxygen species (ROS, O2 (-), H2O2, OH(-)) in whole blood, respiratory activity of blood cells, as well as mitochondrial-dependent ROS formation, and respiratory activity), was performed using EPR spectrometer nOxyscan, spin probe CMH, and oxygen label NOX-15.1, respectively. Furthermore, we investigated the ability of SPECTRA™ to modulate ex vivo cellular inflammatory responses induced by stimulation with exogenous TNF-α and also followed changes in bioavailable NO concentrations. In this clinical study, we demonstrated that administration of SPECTRA™ resulted in statistically significant long-term inhibition of mitochondrial and cellular ROS generation by as much as 17% as well as 3.5-times inhibition in extracellular NADPH system-dependent generation of O2 (-), and nearly complete inhibition of extracellular H2O2 formation. This was reflected in more than two times inhibition of ex vivo cellular inflammatory response and also increases in bioavailable NO concentration. For the first time, we have measured synergetic, biological effects of a natural supplement on changes in OSM and cellular metabolic activity. The unique design and activity of the plant-based natural supplement, in combination with the newly developed and extended Vitality test, demonstrates the potential of using dietary supplements to modulate OSM and also opens the door to future research into the use of natural supplements for supporting optimal health.

ESR techniques for the detection of nitric oxide in vivo as an index of endothelial function.

Plasma nitrite/nitrate levels reflect oxidation of formed nitric oxide (NO ) but are not indicative of endothelial nitric oxide synthase (eNOS) function due to interference by dietary nitrates and reactive oxygen species (ROS). Nitrosyl hemoglobin (NOHb), a metabolic product of nitric oxide, may better correlate with bioavailable NO but it may depend on the activity of different nitric oxide synthase (NOS) isoforms and may be affected by dietary nitrite/nitrate. We examined the correlation between vascular endothelial NO release and circulating blood levels of NOHb. We measured NOHb in blood using electron spin resonance (ESR) spectrometry and also quantified vascular production of NO using colloid Fe(DETC)(2) and ESR in mouse and human venous blood before and after treatment with the beta-blocker carvedilol. Exclusively the inhibition with L-NAME and not the treatment with the selective neuronal nitric oxide synthase (nNOS) inhibitor, N-AANG or with the selective inducible nitric oxide synthase (iNOS) inhibitor, 1400W, halved NOHb formation, which reflects the complete inhibition of NO release by aortic endothelium. The relationship between NOHb and NO production by the endothelium (0.23 microM NOHb to 3.73 microM/hour of NO per mg of aorta dry weight) was found to be identical for both C57Blk/6 mice and for mice with vascular smooth muscle-targeted expression of p22phox associated with strong increase in eNOS activity. Furthermore, the treatment of patients with cardiovascular diseases with carvedilol for 3 weeks increases up to 2 times the circulating NOHb concentration. These results demonstrate the important role of eNOS in the formation of circulating NOHb and suggest that NOHb can be used as a noninvasive marker of endothelial NO production in vivo.