title: Radix angelica elicits both nitric oxide-dependent and calcium influx-mediated relaxation in rat aorta.
abstract: This study examined the vascular relaxation produced by Radix Angelica (AG; Dong Quai) and its possible mechanisms in isolated rat aortic rings precontracted with norepinephrine. The butanolic fraction (AgBt) of the crude extract of AG causes gradual endothelium-independent relaxation, which was unaffected by five different potassium channel inhibitors. AgBt attenuated the CaCl2-induced vasoconstriction in high-potassium depolarized medium; this required less than one-tenth the concentration needed to elicit vascular relaxation. An aqueous fraction (AgDw) of the crude extract induced transient acute relaxation, which was virtually abolished by endothelial ablation and pretreatment with L-NNA. L-Arginine fully reversed the action of L-NNA. Methylene blue and atropine significantly attenuated the relaxation, but indomethacin did not. Ferulic acid, the main active component in AG, relaxed both endothelium-intact and -denuded rings, while L-NNA, methylene blue, or atropine did not modify the relaxation. Ferulic acid also did not attenuate the CaCl2-induced contraction in high-potassium depolarized medium. In conclusion, Radix Angelica leads to both endothelium-dependent and -independent relaxation of isolated rat aorta. Increased formation of NO might contribute to the endothelium-mediated relaxation, while inhibition of the calcium influx might be an important mechanism in direct smooth muscle relaxation. A substance other than ferulic acid might create these effects.
authors.affiliation: Function Research Division, Korea Food Research Institute, Gyeonggi-Do, Korea. mrrhyu@kfri.re.kr
authors.forename: Mee-Ra
authors.initials: MR
authors.lastname: Rhyu
authors.forename: Jung-Hyun
authors.initials: JH
authors.lastname: Kim
authors.forename: Eun-Young
authors.initials: EY
authors.lastname: Kim
mesh_terms: D029969:Angelica / Q000737:chemistry*; D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D000440:Butanols / Q000737:chemistry; D002118:Calcium / Q000378:metabolism* / Q000494:pharmacology; D002121:Calcium Channel Blockers / Q000494:pharmacology; D003373:Coumaric Acids / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000502:physiology; D016166:Free Radical Scavengers / Q000494:pharmacology; D066298:In Vitro Techniques; D008297:Male; D009529:Nicardipine / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism*; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D026902:Potassium Channel Blockers / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D014664:Vasodilation / Q000187:drug effects*; D014867:Water / Q000737:chemistry
chemical_list: D000440:Butanols; D002121:Calcium Channel Blockers; D003373:Coumaric Acids; D016166:Free Radical Scavengers; D010936:Plant Extracts; D026902:Potassium Channel Blockers; D014867:Water; D009569:Nitric Oxide; C004999:ferulic acid; D009529:Nicardipine; D002118:Calcium