Department of Pharmacology, Institute of Biological Sciences, Federal University of Minas Gerais (UFMG), Belo Horizonte, Brazil.
Clin Exp Pharmacol Physiol. 2012 May;39(5):412-6. doi: 10.1111/j.1440-1681.2012.05689.x.
The opioid peptides have been implicated in peripheral antinociception induced by non-opioidergic compounds, including non-steroidal anti-inflammatory drugs and α(2) -adrenoceptor agonists. The aims of the present study were to investigate the possible peripheral antinociceptive effect of cafestol, a diterpene present in the oil derived from coffee beans, and to evaluate the involvement of opioid peptides in its effect. The rat paw pressure test was used to assess antinocipeptive effects. Hyperalgesia was induced by intraplantar injection of prostaglandin E(2) (2 μg/paw). All drugs were locally administered into the hind-paws of male Wistar rats. Intraplantar injection of cafestol (20, 40 and 80 μg) induced peripheral antinociception. The antinociceptive effect of cafestol was due to a local action because the higher dose (80 μg/paw) did not produce any effect in the contralateral paw. The opioid receptor antagonist naloxone (25, 50 and 100 μg/paw) prevented the action of cafestol (80 μg/paw), whereas the aminopeptidase inhibitor bestatin (400 μg/paw) potentiated the antinociceptive effect of cafestol (40 μg/paw). The results of the present study provide evidence that cafestol treatment has a peripheral antinociceptive effect and suggest that this effect is mediated by the release of endogenous opioids.
阿片肽已被牵涉到外周镇痛作用，该作用由非阿片类化合物诱导产生，包括非甾体抗炎药和 α2-肾上腺素受体激动剂。本研究的目的是探讨咖啡豆中提取的油里所含的二萜咖啡醇是否具有外周镇痛作用，并评估其作用是否与阿片肽有关。使用大鼠足底加压实验来评估镇痛效果。通过在足底注射前列腺素 E2（2μg/只）来诱导痛觉过敏。所有药物都被局部注射到雄性 Wistar 大鼠的后爪中。咖啡醇（20、40 和 80μg）的局部注射可诱导外周镇痛。咖啡醇的镇痛作用是局部作用的结果，因为高剂量（80μg/只）对对侧爪没有任何影响。阿片受体拮抗剂纳洛酮（25、50 和 100μg/只）可阻止咖啡醇（80μg/只）的作用，而氨肽酶抑制剂苯丁抑制肽（400μg/只）可增强咖啡醇（40μg/只）的镇痛作用。本研究结果提供了证据表明咖啡醇治疗具有外周镇痛作用，并提示该作用是通过内源性阿片肽的释放来介导的。
