Sánchez-Mendoza María Elena, Castillo-Henkel Carlos, Navarrete Andrés
Facultad de Química, Departamento de Farmacia, Universidad Nacional Autónoma de México, México D.F., 04510, México.
J Pharm Pharmacol. 2008 Feb;60(2):229-36. doi: 10.1211/jpp.60.2.0012.
In this study we investigated the relaxant effect of the aerial parts of Argemone ochroleuca (Papaveraceae), which is used in Mexican traditional medicine for the treatment of various respiratory diseases such as cough, bronchitis and asthma. The alkaloid berberine was identified as one of the active relaxant principles (EC50 = 118.50 +/-3.91 microM) in the dichloromethane extract of A. ochroleuca (EC50 = 78.03 +/- 2.15 microg mL(-1) with 95.12 +/- 3.56% of relaxation). Berberine concentration-dependently relaxed the carbachol-induced precontractions but not histamine- or KCl-induced precontraction. The relaxant effect of berberine was unaffected by the presence of propranolol (3 microM), glibenclamide (10 microM) or ODQ (10microM). However, 2', 5'-dideoxyadenosine (10 microM) blocked the log concentration-response curves of berberine. On the other hand, berberine produced a leftward shift of the log concentration-response curves of isoproterenol, forskolin and nitroprusside. Additionally, berberine produced a parallel rightward shift of the concentration-response curve of carbachol in a competitive manner with a pA2 of 3.87 +/- 0.045. The above results suggest that the relaxant effect of berberine on tracheal muscle is due to its antagonistic effect on muscarinic acetylcholine receptors.
在本研究中，我们调查了白屈菜（罂粟科）地上部分的舒张作用，该植物在墨西哥传统医学中用于治疗各种呼吸道疾病，如咳嗽、支气管炎和哮喘。生物碱小檗碱被鉴定为白屈菜二氯甲烷提取物中的活性舒张成分之一（EC50 = 118.50 +/-3.91 microM）（EC50 = 78.03 +/- 2.15 microg mL(-1)，舒张率为95.12 +/- 3.56%）。小檗碱浓度依赖性地舒张卡巴胆碱诱导的预收缩，但不舒张组胺或氯化钾诱导的预收缩。小檗碱的舒张作用不受普萘洛尔（3 microM）、格列本脲（10 microM）或ODQ（10 microM）的影响。然而，2', 5'-二脱氧腺苷（10 microM）阻断了小檗碱的对数浓度-反应曲线。另一方面，小檗碱使异丙肾上腺素、福斯可林和硝普钠的对数浓度-反应曲线向左移动。此外，小檗碱以竞争性方式使卡巴胆碱的浓度-反应曲线平行右移，pA2为3.87 +/- 0.045。上述结果表明，小檗碱对气管平滑肌的舒张作用归因于其对毒蕈碱型乙酰胆碱受体的拮抗作用。
