Madeira S V F, Rabelo M, Soares P M G, Souza E P, Meireles A V P, Montenegro C, Lima R F, Assreuy A M S, Criddle D N
Laboratório de Farmacologia dos Canais Iônicos--LAFACI, Mestrado Acadêmico em Ciências Fisiológicas, CCS, Universidade Estadual do Ceará, Av. Paranjana 1700, Fortaleza CE 60740-000, Brazil.
Phytomedicine. 2005 Jun;12(6-7):506-9. doi: 10.1016/j.phymed.2003.11.009.
The medicinal plant Ocimum gratissimum L. (Labiatae) is widely encountered in the Northeast of Brasil where it is used to treat digestive problems. Its leaves have an essential oil (EOOG) content whose chemical composition varies according to the time of plant collection. We have compared the effects of the EOOG, collected at 08:00 a.m. (EOOG8) and at 12:00 a.m. (EOOG12), on the relaxation of guinea-pig isolated ileum. Both EOOG8 and EOOG12 (30-300 microg/ml) reversibly relaxed the spontaneous tonus of the guinea-pig ileum in a concentration-dependent manner, with similar IC50 values (49.3 and 23.8 microg/ml, respectively). The magnitude of the decrease in resting tonus was similar to that of the recognised smooth muscle relaxant papaverine. EOOG8 and EOOG12 relaxed 60 mM KCl-precontracted preparations similarly (38.33 +/- 9.91 microg/ml and 35.53 +/- 6.70), whereas a significantly more potent relaxant effect of EOOG12 compared to EOOG8 was observed when tissues were contracted using 10 microM acetylcholine (IC50 values of 69.55 +/- 4.93 and 128.16 +/- 15.70 microg/ml, respectively; p < 0.05). The principal constituents of the essential oil, eugenol and cineole, also relaxed KCl-precontracted preparations, although they were less potent than EOOG, suggesting that they alone were not responsible for EOOG-induced relaxations. Our results show that the essential oil extracted from the leaves of O. gratissimum L., collected at different time periods, exerts significant relaxant effects on isolated guinea-pig ileum which may underlie the therapeutic action of the plant.
药用植物丁香罗勒（唇形科）在巴西东北部广泛分布，当地用其治疗消化问题。其叶片含有挥发油（EOOG），其化学成分随植物采集时间而变化。我们比较了上午8点采集的EOOG（EOOG8）和中午12点采集的EOOG（EOOG12）对豚鼠离体回肠舒张的影响。EOOG8和EOOG12（30 - 300微克/毫升）均以浓度依赖性方式可逆地舒张豚鼠回肠的自发张力，IC50值相似（分别为49.3和23.8微克/毫升）。静息张力降低的幅度与公认的平滑肌松弛剂罂粟碱相似。EOOG8和EOOG12对60 mM氯化钾预收缩的制剂舒张作用相似（分别为38.33±9.91微克/毫升和35.53±6.70），而当用10微摩尔乙酰胆碱使组织收缩时，观察到EOOG12的舒张作用比EOOG8显著更强（IC50值分别为69.55±4.93和128.16±15.70微克/毫升；p<0.05）。挥发油的主要成分丁香酚和桉叶素也能舒张氯化钾预收缩的制剂，尽管它们的效力比EOOG弱，这表明它们单独并不负责EOOG诱导的舒张作用。我们的结果表明，从不同时间段采集的丁香罗勒叶片中提取的挥发油对豚鼠离体回肠具有显著的舒张作用，这可能是该植物治疗作用的基础。
