Different Hypotentive Effects of Various Active Constituents Isolated from Uncaria rhynchophylla / 中草药

ABSTRACT

Hypotensive effects of rhynchophylline, isorhynchophylline, total alkaloid and non-alka-loid fraction isolated from Uncaria rhynchophylla (Miq.) Jacks. were compared. Change in peripheralblood pressure was recorded by inserting a catheter into the right common carotid artery of anaethetizedrat, while each of the four hypotensive constituents was injected individually into the femoral vein by a mi-croinfusion pump. Results of the findings showed that the four constituents in U. rhynchophylla displayeddifferent hypotensive potency in the order of isorhynchophylline [lowering of mean arterial pressure(MAP) by 42.0%] > rhynchophylline (lowering of MAP by 32.1%) > total alkaloid (lowering of MAPby 21.3%) > non-alkaloid fraction (lowering of MAP by 12.4%). It was concluded that isorhyn-chophylline and rhynchophylline were the main hypotensive constituents in U. rhynchophylla.