O'Byrne Dawn J, Devaraj Sridevi, Grundy Scott M, Jialal Ishwarlal
Center for Human Nutrition and the Division of Clinical Biochemistry and Human Metabolism, Department of Pathology, University of Texas Southwestern Medical Center, Dallas, USA.
Am J Clin Nutr. 2002 Dec;76(6):1367-74. doi: 10.1093/ajcn/76.6.1367.
Concord grape juice (CGJ) is a rich source of flavonoids, which have greater antioxidant efficacy in vitro than does alpha-tocopherol; however, the efficacies of flavonoids and alpha-tocopherol in vivo have not been compared.
We compared the in vivo antioxidant efficacy of CGJ with that of alpha-tocopherol in healthy adults.
Subjects were randomly assigned to receive either 400 IU RRR-alpha-tocopherol/d (n = 17) or 10 mL CGJ. kg(-1). d(-1) (n = 15) for 2 wk. Serum oxygen radical absorbance capacity, plasma protein carbonyls, urinary F(2)-isoprostanes, and resistance of LDL to ex vivo oxidation were measured before and after supplementation as markers of antioxidant status and oxidative stress.
After supplementation, plasma alpha-tocopherol increased 92% in subjects who received alpha-tocopherol (P < 0.001); plasma total and conjugated phenols increased 17% (P < 0.01) and 22% (P < 0.001), respectively, in subjects who received CGJ. There was a significant change in plasma triacylglycerols in both groups, but the concentrations were within the normal range. CGJ supplementation was associated with significantly higher triacylglycerols than was alpha-tocopherol supplementation. Both supplementation regimens significantly increased serum oxygen radical absorbance capacity (P < 0.001) and LDL lag time (P < 0.001) and significantly decreased the LDL oxidation rate (P < 0.01), with no significant difference in effectiveness. Protein carbonyl concentrations in native plasma decreased 20% after CGJ supplementation, which was a significantly different response than that after alpha-tocopherol supplementation (P < 0.05).
In healthy adults, 10 mL CGJ. kg(-1). d(-1) increased serum antioxidant capacity and protected LDL against oxidation to an extent similar to that obtained with 400 IU alpha-tocopherol/d but decreased native plasma protein oxidation significantly more than did alpha-tocopherol. CGJ flavonoids are potent antioxidants that may protect against oxidative stress and reduce the risk of free radical damage and chronic diseases.
康科德葡萄汁（CGJ）富含类黄酮，其在体外的抗氧化功效比α-生育酚更强；然而，类黄酮和α-生育酚在体内的功效尚未得到比较。
我们比较了CGJ与α-生育酚在健康成年人中的体内抗氧化功效。
将受试者随机分为两组，一组每天服用400 IU RRR-α-生育酚（n = 17），另一组每天服用10 mL CGJ·kg⁻¹·d⁻¹（n = 15），持续2周。在补充前后测量血清氧自由基吸收能力、血浆蛋白羰基、尿F₂-异前列腺素以及低密度脂蛋白（LDL）对体外氧化的抗性，以此作为抗氧化状态和氧化应激的标志物。
补充后，服用α-生育酚的受试者血浆α-生育酚增加了92%（P < 0.001）；服用CGJ的受试者血浆总酚和共轭酚分别增加了17%（P < 0.01）和22%（P < 0.001）。两组受试者的血浆三酰甘油均有显著变化，但浓度仍在正常范围内。与服用α-生育酚相比，服用CGJ后血浆三酰甘油显著更高。两种补充方案均显著提高了血清氧自由基吸收能力（P < 0.001）和LDL延迟时间（P < 0.001），并显著降低了LDL氧化速率（P < 0.01），二者在有效性上无显著差异。补充CGJ后，天然血浆中的蛋白羰基浓度降低了20%，这与补充α-生育酚后的反应有显著差异（P < 0.05）。
在健康成年人中，每天10 mL CGJ·kg⁻¹·d⁻¹提高血清抗氧化能力并保护LDL免受氧化的程度与每天400 IU α-生育酚相似，但比α-生育酚更显著地降低了天然血浆蛋白氧化。CGJ类黄酮是有效的抗氧化剂，可能预防氧化应激并降低自由基损伤和慢性病风险。
