Division of Systems Biology, Food and Drug Administration (FDA)/NCTR, 3900 NCTR Rd., Jefferson, AR, 72079, USA,
Cardiovasc Toxicol. 2013 Sep;13(3):208-19. doi: 10.1007/s12012-013-9199-x.
When safety concerns forced the removal of ephedra from the market, other botanicals, including Citrus aurantium or bitter orange (BO) were used as replacements. A major component of the BO extract is synephrine, a chemical that is structurally similar to ephedrine. Because ephedrine has cardiovascular effects that may be exacerbated during physical exercise, the purpose of this study was to determine whether extracts containing synephrine produced adverse effects on the cardiovascular system in exercising rats. Sprague-Dawley rats were dosed daily by gavage for 28 days with 10 or 50 mg of synephrine/kg body weight from one of two different extracts; caffeine was added to some doses. The rats ran on a treadmill for 30 min/day, 3 days/week. Heart rate, blood pressure, body temperature, and QT interval were monitored. Both doses of both extracts significantly increased systolic and diastolic blood pressure for up to 8 h after dosing. Effects on heart rate and body temperature appeared to be due primarily to the effects of caffeine. These data suggest that the combination of synephrine, caffeine, and exercise can have significant effects on blood pressure and do not appear to be effective in decreasing food consumption or body weight.
当安全问题迫使麻黄从市场上撤出时，其他植物药，包括柑橘或苦橙（BO）被用作替代品。BO 提取物的主要成分是辛弗林，一种与麻黄碱结构相似的化学物质。由于麻黄碱在运动过程中可能会对心血管系统产生影响，因此本研究旨在确定含有辛弗林的提取物是否会对运动大鼠的心血管系统产生不良影响。Sprague-Dawley 大鼠每天通过灌胃给予 10 或 50mg/kg 体重的两种不同提取物之一的辛弗林，持续 28 天；一些剂量中添加了咖啡因。大鼠每天在跑步机上跑步 30 分钟，每周 3 天。监测心率、血压、体温和 QT 间期。两种提取物的两种剂量在给药后长达 8 小时内均显著升高收缩压和舒张压。对心率和体温的影响似乎主要是咖啡因的作用。这些数据表明，辛弗林、咖啡因和运动的组合可能对血压有显著影响，而且似乎不能有效地减少食物摄入或体重。
