Current evidence supports a significant association between fruit and vegetable intake and health. In this study, we assessed the effect of consuming a vegetable-soup"gazpacho"on vitamin C and biomarkers of oxidative stress and inflammation in a healthy human population. We also examined the association between vitamin C and F(2)-isoprostanes (8-epiPGF(2alpha)), uric acid (UA), prostaglandin E(2) (PGE(2)), monocyte chemotactic protein-1 (MCP-1), and the cytokines, tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), and IL-6. Gazpacho is a Mediterranean dish defined as a ready-to-use vegetable soup, containing approximately 80% crude vegetables rich in vitamin C. Subjects (6 men, 6 women) enrolled in this study consumed 500 mL/d of gazpacho corresponding to an intake of 72 mg of vitamin C. On d 1, subjects consumed the gazpacho in one dose; from d 2 until the end of the study, d 14, 250 mL was consumed in the morning and 250 mL in the afternoon. Blood was collected before drinking the soup (baseline) and on d 7 and 14. Baseline plasma vitamin C concentrations did not differ between men and women (P = 0.060). Compared with baseline, the vitamin C concentration was significantly higher on d 7 and 14 of the intervention in both men and women (P<0.05). Baseline plasma levels of UA and F(2)-isoprostanes were higher (P

Intravenous administration of vitamin C has been shown to decrease oxidative stress and, in some instances, improve physiological function in adult humans. Oral vitamin C administration is typically less effective than intravenous, due in part to inferior vitamin C bioavailability. The purpose of this study was to determine the efficacy of oral delivery of vitamin C encapsulated in liposomes. On 4 separate randomly ordered occasions, 11 men and women were administered an oral placebo, or 4 g of vitamin C via oral, oral liposomal, or intravenous delivery. The data indicate that oral delivery of 4 g of vitamin C encapsulated in liposomes (1) produces circulating concentrations of vitamin C that are greater than unencapsulated oral but less than intravenous administration and (2) provides protection from ischemia-reperfusion-mediated oxidative stress that is similar to the protection provided by unencapsulated oral and intravenous administrations.

Curcumin (Cur) is a promising antioxidant and anticancer drug, but several recent studies indicate that Cur exerts its anticancer activity through promoting reactive oxygen species (ROS) generation. In the present study, concentration-dependent regulation of Cur on cell proliferation, viability and ROS generation, and effect of water-soluble antioxidants ascorbic acid (ASA), N-acetyl-cysteine (NAC) and reduced glutathione (GSH) on the antioxidant and anticancer activity of Cur were investigated in human myeloid leukemia cells (HL-60 cells). We found that although Cur concentration- and time-dependently decreased the proliferation and viability of cells, its effect on ROS generation (as indicated by the level of malondialdehyde, MDA) varied with its concentrations. I.e., low concentrations of Cur diminished the ROS generation, while high Cur promoted it. Combined with the opposite effect of 50 microM H2O2 on low or high Cur-induced MDA alteration, cell proliferation arrest and cell death, these results proved that low Cur exerted its anticancer activity through diminishing ROS generation in HL-60 cells, while high Cur through promoting ROS generation. Further studies showed that all water-soluble antioxidants ASA, NAC and GSH significantly enhanced both the antioxidant and the anticancer activity of low Cur. Considering that the extra accumulation of ROS is harmful to normal cells, the data presented here indicate that instead of using high doses, combining low doses of Cur with water-soluble antioxidants is a better strategy for us to improve the anticancer activity of Cur.