Laboratorio de Neuroquímica, Instituto Nacional de Pediatría, 04530 México D.F., Mexico.
Toxicology. 2010 Sep 30;276(1):41-8. doi: 10.1016/j.tox.2010.06.013. Epub 2010 Jul 8.
Arnica (Heterotheca inuloides) is a widely used medicinal plant in México; it has been recognized as anti-inflammatory, analgesic, cytotoxic, scavenger of superoxide anion and also as a preventive of lipid peroxidation. In vivo studies have demonstrated a hepatoprotective action of the methanolic extract of this plant as well as of quercetin, one of its main components, and the evidence obtained pointed out to an antioxidant mechanism. In this work, we focused on the free radical scavenging capacity of acetonic and methanolic extracts of H. inuloides in comparison with reference compounds. The two extracts were 2-12 times more effective (IC50, microg/mL) than the reference compounds to cope with the following radicals or molecules tested: 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS(+)), 2,2-diphenyl-1-picrylhydrazyl (DPPH), peroxynitrite (ONOO(-)), superoxide (O2(-)), singlet oxygen ((1)O(2)), hypochlorous acid (HOCl), hydrogen peroxide (H2O2), hydroxyl (OH). Additionally, five secondary metabolites isolated from the methanolic extract displayed potent concentration-dependent antioxidant effects against reactive oxygen species produced in vitro (IC50 values in the range of 0.018-4.31mg/mL). d-Chiro-inositol showed the higher antioxidant effect against O2(-), H2O2 and OH while spinasterol and quercetin were the most active against (1)O(2) and ONOO(-), respectively. The antioxidant properties of the extracts and metabolites tested partially support the wide use of this plant in traditional medicine.
山金车（Heterotheca inuloides）是墨西哥广泛使用的药用植物；它已被公认为具有抗炎、镇痛、细胞毒性、超氧阴离子清除剂，以及预防脂质过氧化的作用。体内研究表明，该植物的甲醇提取物以及其主要成分之一槲皮素具有肝保护作用，并且获得的证据表明其作用机制为抗氧化。在这项工作中，我们专注于比较山金车的丙酮和甲醇提取物与参考化合物的自由基清除能力。与参考化合物相比，这两种提取物对以下自由基或测试分子的有效作用（IC50，μg/mL）高 2-12 倍：2,2'-偶氮双（3-乙基苯并噻唑啉-6-磺酸）（ABTS(+）），2,2-二苯基-1-苦基肼（DPPH），过氧亚硝酸盐（ONOO(-）），超氧阴离子（O2(-）），单线态氧（(1)O(2）），次氯酸（HOCl），过氧化氢（H2O2），羟基（OH）。此外，从甲醇提取物中分离出的五种次生代谢物对体外产生的活性氧具有强烈的浓度依赖性抗氧化作用（IC50 值在 0.018-4.31mg/mL 范围内）。d-手性肌醇对 O2(-）、H2O2 和 OH 的抗氧化作用最强，而 Spinasterol 和槲皮素对(1)O(2）和 ONOO(-）的作用最活跃。测试的提取物和代谢物的抗氧化特性部分支持了该植物在传统医学中的广泛应用。
