Antihypertensive effect of French maritime pine bark extract (Flavangenol): possible involvement of endothelial nitric oxide-dependent vasorelaxation.

Abstract

OBJECTIVE:

French maritime pine bark extract (Flavangenol) has been known to produce an endothelium-dependent vasodilatory effect. In the present study, we evaluated whether a dietary supplementation of Flavangenol exhibits antihypertensive action using deoxycorticosterone acetate (DOCA)-salt hypertensive rats. Moreover, we investigated the mechanisms of an in-vitro vasorelaxant response to Flavangenol.

METHODS AND RESULTS:

The development of DOCA-salt-induced hypertension during a 5-week treatment period was significantly suppressed by feeding a Flavangenol-containing diet. Increased superoxide (O2-) production in vascular tissues after the DOCA-salt treatment tended to be suppressed by the Flavangenol feeding, whereas decreased vasorelaxant responses to acetylcholine in endothelium-intact aortas of DOCA-salt rats were significantly improved in Flavangenol-fed rats. Moreover, Flavangenol itself caused a potent endothelium-dependent vasorelaxation in aorta and mesenteric vascular bed. Pretreatment with a nitric oxide synthase inhibitor, NG-nitro-L-arginine methyl ester, or a soluble guanylate cyclase inhibitor 1H-[1,2,4]oxadiazolo-[4,3-a]quinoxalin-1-one abolished the Flavangenol-induced vasorelaxation in the aorta. At the same concentration, Flavangenol produced a rapid increase in phosphorylated-endothelial nitric oxide synthase (Ser1177) protein expression in aortic tissues, without affecting levels of total endothelial nitric oxide synthase protein expression. Flavangenol-induced vasorelaxant effect was not observed in aortic rings of endothelial nitric oxide synthase-deficient mice. Flavangenol feeding failed to suppress the development of hypertension in chronically nitric oxide synthase-inhibited rats.

CONCLUSION:

Thus, it seems likely that the antihypertensive effect of Flavangenol is attributable to both its antioxidative property-related protective effects against endothelial dysfunction and the endothelium-dependent vasorelaxant effect, which is mediated by endothelial nitric oxide synthase activation.

• Authors: Chol-Jun Kwak, Eriko Kubo, Kiwako Fujii, Yuri Nishimura, Shuhei Kobuchi, Mamoru Ohkita, Makiko Yoshimura, Yoshinobu Kiso, Yasuo Matsumura
• Journal: Journal of hypertension (J Hypertens) Vol. 27 Issue 1 Pg. 92-101 (Jan 2009) ISSN: 0263-6352 [Print] England
• PMID: 19145776 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antihypertensive Agents
• Biflavonoids
• Plant Extracts
• Proanthocyanidins
• flavangenol
• Superoxides
• Nitroarginine
• Nitric Oxide
• Desoxycorticosterone
• Sodium Chloride
• Nitric Oxide Synthase Type III

Topics

• Animals
• Antihypertensive Agents (pharmacology)
• Biflavonoids (pharmacology)
• Body Weight (drug effects)
• Desoxycorticosterone
• Male
• Nitric Oxide (physiology)
• Nitric Oxide Synthase Type III (physiology)
• Nitroarginine (pharmacology)
• Plant Extracts (pharmacology)
• Proanthocyanidins (pharmacology)
• Rats
• Rats, Sprague-Dawley
• Sodium Chloride
• Superoxides (metabolism)
• Vasodilation (drug effects)