Parry O, Okwuasaba F K, Ekpenyong K I, Ashraf C M
J Ethnopharmacol. 1986 Oct;18(1):63-88. doi: 10.1016/0378-8741(86)90044-9.
A methanol extract of the roots of Olax gambecola induced a biphasic contractile response consisting of a transitory initial rapid contraction (Phase I), followed by a slowly developing sustained increase in basal tone (Phase II) on rat fundus, antrum, guinea pig taenia coli, rabbit jejunum and aorta. The Phase I contraction was abolished by atropine, attenuated significantly by indomethacin and potentiated by physostigmine while the Phase II response was unaffected. Hexamethonium, morphine, serotonin (5-HT) antagonists or desensitization of 5-HT receptors did not alter either the Phase I or the Phase II contractions. Calcium channel blockers and procedures affecting calcium translocation abolished the Phase I contraction while only reducing the Phase II contractions. Transmural electrical stimulation produced contractions of the fundus which were attenuated by the extract. Single bolus injections of extract produced a rapid fall in blood pressure in both normotensive and spontaneously hypertensive rats but intravenous infusion resulted in a sustained fall in blood pressure which was maintained throughout the infusion period. Chronic i.p. administration of extract to spontaneously hypertensive rats reduced blood pressure markedly but did not alter the blood pressure of normotensive animals. The hypotensive response to single bolus injections was abolished by atropine and potentiated by physostigmine. The activity profile of the extract suggests the presence of at least two active principles in the crude extract of Olax gambecola used in this study.
冈贝油麻木根的甲醇提取物对大鼠胃底、胃窦、豚鼠结肠带、兔空肠和主动脉产生双相收缩反应，包括短暂的初始快速收缩（I期），随后是基础张力缓慢发展的持续增加（II期）。I期收缩可被阿托品消除，吲哚美辛可使其显著减弱，毒扁豆碱可使其增强，而II期反应不受影响。六甲铵、吗啡、5-羟色胺（5-HT）拮抗剂或5-HT受体脱敏对I期或II期收缩均无改变。钙通道阻滞剂和影响钙转运的操作可消除I期收缩，而仅减少II期收缩。跨壁电刺激可引起胃底收缩，提取物可使其减弱。单次推注提取物可使正常血压和自发性高血压大鼠的血压迅速下降，但静脉输注则导致血压持续下降，且在整个输注期间维持不变。对自发性高血压大鼠进行慢性腹腔注射提取物可显著降低血压，但对正常血压动物的血压无影响。阿托品可消除单次推注引起的降压反应，毒扁豆碱可使其增强。提取物的活性特征表明，本研究中使用的冈贝油麻木粗提物中至少存在两种活性成分。
