Effects of berberine on angiotensin-converting enzyme and NO/cGMP system in vessels.
The present study was designed to examine the relaxant and anticonstrictive effects of berberine in the isolated thoracic aorta in rats. Intravenous injection of berberine lowered the mean arterial pressure (MAP) of anesthesized rats in a dose-dependent manner. The angiotensin-converting enzyme (ACE) activities were inhibited significantly by the addition of berberine in a dose-dependent manner of which the IC50 value of berberine for ACE was 42 micrograms/ml (125 microM). In the endothelium-intact rings, angiotensin I-induced contraction was markedly attenuated by prior exposure of aortic rings to berberine. Treatment of the intact aortic rings with berberine (10 micrograms/ml) increased the NOx and cGMP productions relative to the vehicle-treated group. Berberine induced a dose-dependent relaxation in phenylephrine-precontracted aortic rings, but NG-nitro-L-arginine methyl ester (L-NAME)-pretreated intact aortic rings or functional removal of the endothelium attenuated the berberine-induced relaxation without an effect on maximum response. These results suggest that berberine has a hypotensive effect, at least in part, via the inhibition of ACE and direct release of NO/cGMP in the vascular tissues.
Kang
Dae Gill
DG
Department of Herbal Resources, Professional Graduate School of Oriental Medicine and Medicinal Resources Research Center (MRRC), Wonkwang University, Iksan, Chonbuk, 570-749, Republic of Korea.
Sohn
Eun Jin
EJ
Kwon
Eui Kwang
EK
Han
Jong Hyun
JH
Oh
Hyuncheol
H
Lee
Ho Sub
HS
D000758:Anesthesia; D000803:Angiotensin I / Q000037:antagonists & inhibitors / Q000494:pharmacology; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology*; D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects / Q000378:metabolism; D001599:Berberine / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D001808:Blood Vessels / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D003124:Colorimetry; D000242:Cyclic AMP / Q000378:metabolism / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000502:physiology; D066298:In Vitro Techniques; D007537:Isometric Contraction / Q000187:drug effects; D008297:Male; D009126:Muscle Relaxation / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects; D009569:Nitric Oxide / Q000378:metabolism / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014662:Vasoconstrictor Agents / Q000494:pharmacology
D000806:Angiotensin-Converting Enzyme Inhibitors; D014662:Vasoconstrictor Agents; D001599:Berberine; D009569:Nitric Oxide; D000803:Angiotensin I; D000242:Cyclic AMP