Centre of Complementary Medicine Research, School of Science and Health, University of Western Sydney, Locked Bag 1797, Penrith, NSW 2751, Australia.
BMC Complement Altern Med. 2013 Dec 27;13:373. doi: 10.1186/1472-6882-13-373.
Age is the leading risk factor for acute and chronic neurodegenerative diseases. The Shen Nong Ben Cao Jing, the oldest known compendium of Chinese materia media, lists herbal medicines that were believed to exert neither fast acting pharmacological effects nor discernible toxicity, but to promote general health and longevity. In modern terms, these herbal medicines could be considered as complementary health care products for prevention rather than treatment of diseases. In the present study, we examined whether a selection of 13 such herbal medicines exhibited neuroprotective activity.
The antioxidant capacity of the herbal extracts was determined using three non-cellular assays measuring the total phenol content (FCR assay), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity and oxygen radical absorbance capacity (ORAC). Cytotoxic effects of the herbal extracts were assayed in cultured mouse cortical neurons and their neuroprotective activities were studied using staurosporine-induced apoptosis of the cultured neurons.
Most of the herbal extracts showed negligible toxic effects at 100 μg/ml. However, Polygonum multiflorum and Rhodiola rosea exhibited some neurotoxicity at this concentration. Extracts of Ganoderma lucidum, Glycyrrhiza glabra, Schizandra chinensis, and Polygonum cuspidatum inhibited staurosporine-induced apoptosis by 30 - 50% in a dose-dependent manner. The neuroprotective effects of Polygonum cuspidatum were predominantly due to its major ingredient, resveratrol. The effective herbal extracts showed various levels of reactive oxygen species (ROS) scavenging capacity, which was significantly correlated with their neuro- protective activity. However, P. multiflorum and R. rosea extracts proved to be the exception as they exhibited a high level of antioxidant capacity, but did not exhibit neuroprotective effects in cell-based assay.
This in vitro study provides evidence for neuroprotective activity of some Chinese herbal medicines traditionally used to promote healthy ageing and longevity. Our results provide a justification for further study of these herbal extracts in neurodegenerative animal models to assess their safety and effectiveness as a basis for subsequent clinical trials. These herbal medicines might potentially offer a novel preemptive neuroprotective approach in neurodegenerative diseases and might be developed for use in persons at risk.
年龄是急性和慢性神经退行性疾病的主要危险因素。《神农本草经》是已知最古老的中药专著，其中列出了一些草药，据信这些草药既没有快速的药理作用，也没有明显的毒性，但能促进整体健康和长寿。用现代术语来说，这些草药可以被视为预防疾病而不是治疗疾病的补充保健品。在本研究中，我们研究了 13 种此类草药中的一部分是否具有神经保护活性。
使用三种非细胞测定法测定草药提取物的抗氧化能力，这些测定法分别测量总酚含量（FCR 测定法）、2,2-二苯基-1-苦基肼（DPPH）自由基清除能力和氧自由基吸收能力（ORAC）。在培养的小鼠皮质神经元中测定草药提取物的细胞毒性，并研究其在星形孢菌素诱导的培养神经元凋亡中的神经保护活性。
大多数草药提取物在 100μg/ml 时显示出可忽略的毒性作用。然而，何首乌和红景天在该浓度下表现出一定的神经毒性。灵芝、甘草、五味子和虎杖的提取物以剂量依赖性方式抑制 30-50%的星形孢菌素诱导的凋亡。虎杖的神经保护作用主要归因于其主要成分白藜芦醇。有效的草药提取物显示出不同水平的活性氧（ROS）清除能力，这与其神经保护活性显著相关。然而，何首乌和红景天提取物是例外，因为它们表现出高水平的抗氧化能力，但在基于细胞的测定中没有表现出神经保护作用。
这项体外研究为传统上用于促进健康衰老和长寿的一些中草药的神经保护活性提供了证据。我们的结果为进一步研究这些草药提取物在神经退行性动物模型中的安全性和有效性提供了依据，以便评估它们作为随后临床试验的基础。这些草药可能为神经退行性疾病提供一种新的预防性神经保护方法，并可能被开发用于高危人群。
