The effects of chronic treatment with Morus bombycis KOIDZUMI in spontaneously hypertensive rats.
The present study was performed to evaluate the antihypertensive effects of Morus bombycis KOIDZUMI (MK) in spontaneously hypertensive rats (SHRs). In addition, the effects on vascular responses and cardiac functions were also investigated. In isolated rat aortic preparations, the 100% ethanol extract of MK exhibited a potent vascular relaxant effect with IC(50) value of 3.9 microg/ml, and this vasorelaxant effect was completely abolished by pretreatment of the aortic tissues with N(G)-nitro-L-arginine methyl ester or the denudation of endothelial layer. In isolated rat hearts, the MK extract significantly reduced cardiac functions such as left ventricular developed pressure and heart rate. In an antihypertensive study in SHRs, long-term administration with MK extracts (10, 30, 100 mg/kg) for 42 d dose-dependently decreased systolic blood pressure (approximately 20 mmHg). In SHRs, MK extract enhanced the aortic relaxation to acetylcholine and sodium nitroprusside after 42 d of treatment. In addition, lipid peroxidation and DNA damage in liver of SHRs were also attenuated by long-term treatment with MK extract. These results suggest that chronic treatment with MK extract exerts an antihypertensive effect in SHRs, and its direct vasorelaxant, negative inotropic actions, and anti-oxidant properties may contribute to reduce the elevated blood pressure.
Oh
Kwang-Seok
KS
Drug Discovery Division, Korea Research Institute of Chemical Technology, Daejeon, Republic of Korea.
Han
Woong
W
Wang
Myeong-Hyeon
MH
Lee
Byung Ho
BH
D000818:Animals; D004305:Dose-Response Relationship, Drug; D006973:Hypertension / Q000188:drug therapy*; D031625:Morus; D009200:Myocardial Contraction / Q000187:drug effects; D018384:Oxidative Stress; D008517:Phytotherapy; D010936:Plant Extracts / Q000627:therapeutic use*; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D017207:Rats, Sprague-Dawley; D014664:Vasodilation / Q000187:drug effects
D010936:Plant Extracts