Departamento de Pharmacology and Chemistry of Medicinal Plants, Centro de Investigación Biomédica del Sur (CIBIS), Instituto Mexicano del Seguro Social (IMSS), Argentina 1, Col. Centro, 62790 Xochitpec, Morelos, Mexico.
J Ethnopharmacol. 2011 Nov 18;138(2):261-7. doi: 10.1016/j.jep.2011.09.010. Epub 2011 Sep 16.
Loeselia mexicana (Lam.) Brand has been used in Mexican Traditional Medicine to treat "espanto" or "susto" (fear), which is a culturally affiliated syndrome whose symptomatology comprises loss of appetite, difficulty in sleeping, and also nausea and fatigue, with a sensation of fear or risk - real or imagined - to external stimuli.
The anxiolytic effect of the standardized methanol extract of Loeselia mexicana, with regard to its content of coumarin daphnoretin, was researched utilizing the elevated plus maze (EPM) in order to demonstrate whether the biological effect produced by the plant is antagonized by drugs that block γ-amino butyric acid (GABA)ergic transmission.
The methanolic extract of Loeselia mexicana (LmMeOH) was tested at different doses on the EPM and then the interaction of this extract was evaluated in the same model with different GABAergic drugs, such as flumazenil (FLU) 10mg/kg, bicuculline (BIC) 5mg/kg, pentylenetetrazole (PTZ) 10mg/kg, and picrotoxin (PTX) 2mg/kg. The effect of all of these treatments was evaluated by means of the open field test (OFT). Coumarin content was measured by the high performance liquid chromatography (HPLC) technique.
The 200- and 400-mg/kg doses of methanolic extract containing 3.14 and 6.28 mg of daphnoretin, respectively, induced an anxiolytic effect in the EPM without modification of the spontaneous motor activity. The anxiolytic activity of 200mg/kg of methanolic extract in EPM-exposed mice was antagonized by PTX, BIC, and FLU, but not by PTZ.
The data presented here indicate that the Loeselia mexicana Brand methanolic extract possesses a significant anxiolytic effect that appears to be mediated in part by activation of the GABAergic system.
Loeselia mexicana（Lam.）Brand 已被用于墨西哥传统医学中治疗“espanto”或“susto”（恐惧），这是一种与文化相关的综合征，其症状包括食欲不振、睡眠困难，以及恶心和疲劳，伴有对外部刺激的恐惧或风险感-真实或想象的。
本研究旨在利用高架十字迷宫（EPM）研究 Loeselia mexicana 标准化甲醇提取物的抗焦虑作用及其香豆素 daphnoretin 的含量，以证明植物产生的生物学效应是否被阻断γ-氨基丁酸（GABA）能传递的药物所拮抗。
在 EPM 上测试了 Loeselia mexicana（LmMeOH）的甲醇提取物在不同剂量下的作用，然后在相同模型中评估了该提取物与不同 GABA 能药物的相互作用，如氟马西尼（FLU）10mg/kg、荷包牡丹碱（BIC）5mg/kg、戊四氮（PTZ）10mg/kg 和 士的宁（PTX）2mg/kg。所有这些治疗的效果都通过旷场试验（OFT）进行了评估。香豆素含量通过高效液相色谱（HPLC）技术测量。
含有 3.14 和 6.28mg daphnoretin 的 200-和 400-mg/kg 剂量的甲醇提取物分别在 EPM 中诱导出抗焦虑作用，而不改变自发运动活动。在 EPM 暴露的小鼠中，200mg/kg 甲醇提取物的抗焦虑活性被 PTX、BIC 和 FLU 拮抗，但不受 PTZ 影响。
这里呈现的数据表明，Loeselia mexicana Brand 甲醇提取物具有显著的抗焦虑作用，部分似乎是通过激活 GABA 能系统介导的。
