Pomegranate juice protects nitric oxide against oxidative destruction and enhances the biological actions of nitric oxide

Louis J. Ignarro, Russell E. Byrns, Daigo Sumi, Filomena de Nigris, Claudio Napoli

Research output: Contribution to journalArticlepeer-review

Abstract

Pomegranate juice (PJ), which is a rich source of potent flavonoid antioxidants, was tested for its capacity to protect nitric oxide (NO) against oxidative destruction and enhance the biological actions of NO. Employing chemiluminescence headspace analysis, PJ was found to be a potent inhibitor of superoxide anion-mediated disappearance of NO. PJ was much more potent than Concord grape juice, blueberry juice, red wine, ascorbic acid, and dl-α-tocopherol. As little as 3 μl of a 6-fold dilution of PJ, in a reaction volume of 5000 μl, produced a marked antioxidant effect, whereas 300 μl of undiluted blueberry juice or nearly 1000 μl of undiluted Concord grape juice were required to produce similar effects. PJ and other antioxidant-containing products were found to augment the anti-proliferative action of NO (DETA/NO) on vascular smooth muscle cell (rat aorta) proliferation. PJ was much more effective than the other products tested and elicited no effects when tested alone in the absence of added NO. Similarly, neither PJ nor the other products enhanced the anti-proliferative action of α-difluoromethylornithine, a stable substance that inhibits cell growth by NO-independent mechanisms. In order to determine whether PJ is capable of increasing the production of NO by vascular endothelial cells, PJ was tested for its capacity to upregulate and/or activate endothelial NO synthase (eNOS) in bovine pulmonary artery endothelial cells. PJ elicited no effects on eNOS protein expression or catalytic activity. Moreover, PJ did not enhance promoter activity in the eNOS gene (COS-7 cells transfected with eNOS). These observations indicate that PJ possesses potent antioxidant activity that results in marked protection of NO against oxidative destruction, thereby resulting in augmentation of the biological actions of NO.

Original languageEnglish
Pages (from-to)93-102
Number of pages10
JournalNitric Oxide - Biology and Chemistry
Volume15
Issue number2
DOIs
Publication statusPublished - Sep 2006

Keywords

  • Antioxidant activity
  • Flavonoids
  • Nitric oxide
  • Polyphenols
  • Vascular smooth muscle proliferation

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology

Fingerprint Dive into the research topics of 'Pomegranate juice protects nitric oxide against oxidative destruction and enhances the biological actions of nitric oxide'. Together they form a unique fingerprint.

Cite this