The role of nutrition and nutraceutical supplements in the treatment of hypertension

Table 2 Oxidative stress induces endothelial dysfunction, vascular disease and hypertension. Host protective factors include enzymatic and non-enzymatic defenses influenced by diet and nutrients

The cytotoxic reactive oxygen species and the natural defense mechanisms
Reactive oxygen apecies		Antioxidant defense mechanisms
Free radicals		Enzymatic scavengers
O2•-	Superoxide anion radical	SOD	Superoxide dismutase
OH•	Hydroxyl radical		2O2•- + 2H+→ H2O2 + O2
ROO•	Lipid peroxide (peroxyl)	CAT	Catalase (peroxisomal-bound)
RO•	Alkoxyl		2H2O2→ O2 + H2O
RS•	Thiyl	GTP	Glutathione peroxidase
NO•	Nitric oxide		2GSH + H2O2→ GSSG + 2H2O
NO2•	Nitrogen dioxide		2GSH + ROOH → GSSG + ROH + 2H2O
ONOO-	Peroxynitrite
CCl3•	Trichloromethyl	Nonenzymatic scavengers
		Vitamin A
Non-radicals		Vitamin C (ascorbic acid)
H2O2	Hydrogen peroxide	Vitamin E (α-tocopherol)
HOCl	Hypochlorous acid	β-carotene
ONOO-	Peroxynitrite	Cysteine
1O2	Singlet oxygen	Coenzyme Q
The superscripted bold dot indicates an unpaired electron and the negative charge indicates a gained electron. GSH, reduced glutathione; GSSG, oxidized glutathione; R, lipid chain. Singlet oxygen is an unstable molecule due to the two electrons present in its outer orbit spinning in opposite directions.		Uric acid
		Flavonoids
		Sulfh ydryl group
		Thioether compounds