Nencini Cristina, Cavallo Federica, Bruni Giancarlo, Capasso Anna, De Feo Vincenzo, De Martino Laura, Giorgi Giorgio, Micheli Lucia
Dipartimento di Farmacologia Giorgio Segre, Università degli Studi di Siena, Via delle Scotte, 6-53100 Siena, Italy.
J Ethnopharmacol. 2006 May 24;105(3):352-7. doi: 10.1016/j.jep.2005.11.022. Epub 2006 Jan 6.
Iresine herbstii Hook. (Amaranthaceae) and Brugmansia arborea (L.) Lagerheim (Solanaceae) are used in the northern Peruvian Andes for magic-therapeutical purposes. The traditional healers use Iresine herbstii with the ritual aim to expel bad spirits from the body. Furthermore, Iresine herbstii was used in association with other plants, such as Trichocereus pachanoi Britt. et Rose, for divination, to diagnose diseases, and to take possession of another identity. Also, species of Brugmansia have been reported to be used during ritual practices for magical and curative purposes. Given the above evidence, the aim of the present study is to evaluate if the central effects of Iresine herbstii and Brugmansia arborea could be associated with interaction with SNC receptors. Two Iresine herbstii extracts (methanolic and aqueous) and one Brugmansia arborea aqueous extract were tested for in vitro affinity on 5-HT(1A), 5-HT(2A), 5-HT(2C), D1, D2, alpha(1), and alpha(2) receptors by radioligand binding assays. The biological materials for binding assay (cerebral cortex) were taken from male Sprague-Dawley rats. The extracts affinity for receptors is definite as inhibition percentage of radioligand/receptor binding and measured as the radioactivity of remaining complex radioligand/receptor. The data obtained for Iresine extracts have shown a low affinity for the 5-HT(1A) receptor and no affinity for 5-HT(2A) receptor. Otherwise the methanolic extract showed affinity for 5-HT(2C) receptor (IC(50): 34.78 microg/ml) and for D1 receptor (IC(50): 19.63 microg/ml), instead the Iresine aqueous extract displayed a lower affinity for D1 (48.3% at the maximum concentration tested) and a higher value of affinity for D2 receptors (IC(50): 32.08 microg/ml). The Brugmansia aqueous extract displayed affinity for D1 receptors (IC(50): 17.68 microg/ml), D2 receptors (IC(50): 15.95 microg/ml) and weak affinity for the serotoninergic receptors. None of the three extracts showed relevant affinity to the alpha(1), and alpha(2) receptors. The results of our experiments indicate that Iresine herbstii methanolic extract was able to interact with the central 5-HT(2C) and D1 receptors and Iresine herbstii aqueous extract showed affinity for D2 receptors, thus confirming their ritual use. Instead Brugmansia arborea was able to interact only with the central dopamine receptors tested. Parallel studies are currently in progress for evaluating the extracts affinity and active components towards these and other receptor types (GABAergic).
红叶苋（苋科）和木本曼陀罗（茄科）在秘鲁北部安第斯山脉地区被用于魔法治疗目的。传统治疗师使用红叶苋旨在通过仪式将恶灵从体内驱除。此外，红叶苋还与其他植物如多枝刺仙人球一起用于占卜、诊断疾病以及获得另一种身份。同样，据报道木本曼陀罗的一些物种在仪式活动中被用于魔法和治疗目的。鉴于上述证据，本研究的目的是评估红叶苋和木本曼陀罗的中枢效应是否可能与它们和5-羟色胺能（SNC）受体的相互作用有关。通过放射性配体结合试验，对两种红叶苋提取物（甲醇提取物和水提取物）以及一种木本曼陀罗水提取物进行了体外对5-羟色胺（5-HT）1A、5-HT2A、5-HT2C、多巴胺D1、D2、α1和α2受体的亲和力测试。用于结合试验的生物材料（大脑皮层）取自雄性斯普拉格-道利大鼠。提取物对受体的亲和力通过放射性配体/受体结合的抑制百分比来确定，并通过剩余放射性配体/受体复合物的放射性来测量。红叶苋提取物的数据显示其对5-HT1A受体亲和力较低，对5-HT2A受体无亲和力。另外，甲醇提取物对5-HT2C受体（半数抑制浓度（IC50）：34.78微克/毫升）和D1受体（IC50：19.63微克/毫升）显示出亲和力，而红叶苋水提取物对D1受体的亲和力较低（在测试的最大浓度下为48.3%），对D2受体的亲和力较高（IC50：32.08微克/毫升）。木本曼陀罗水提取物对D1受体（IC50：17.68微克/毫升）、D2受体（IC50：15.95微克/毫升）显示出亲和力，对5-羟色胺能受体显示出较弱的亲和力。三种提取物对α1和α2受体均未显示出明显的亲和力。我们的实验结果表明，红叶苋甲醇提取物能够与中枢5-HT2C和D1受体相互作用，红叶苋水提取物对D2受体显示出亲和力，从而证实了它们在仪式中的用途。而木本曼陀罗仅能与所测试的中枢多巴胺受体相互作用。目前正在进行平行研究，以评估这些提取物对这些及其他受体类型（γ-氨基丁酸能）的亲和力和活性成分。
