Tang Yi-Na, He Xi-Cheng, Ye Min, Huang Hao, Chen Hong-Li, Peng Wan-Ling, Zhao Zhong-Zhen, Yi Tao, Chen Hu-Biao
School of Chinese Medicine, Hong Kong Baptist University, Kowloon Tong, Hong Kong Special Administrative Region.
Department of Natural Medicines, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Beijing 100191, China.
J Ethnopharmacol. 2015 Dec 4;175:451-5. doi: 10.1016/j.jep.2015.10.004. Epub 2015 Oct 9.
As folk medicines used in China since 1950s, Dioscorea nipponica Makino (DN), D. panthaica Prain et Burkill (DP), and D. zingiberensis C.H. Wright (DZ) are regarded as having more or less the same traditional therapeutic actions, such as activating blood, relieving pain, and dispersing swelling. It is noteworthy that, of the 49 species of the genus Dioscorea distributed in China, based on such traditional efficacies, only these three have been further developed as effective single-herb medicines for treating cardiovascular diseases by the modern pharmaceutical industry. In our previous study, it was found that the chemical compositions of DN and DP were similar, and both were distinct from that of DZ. Hence, whether their different chemical profiles support their anti-IHD (ischemic heart disease) activity in common still needs to be answered. So far it is still unknown whether the efficacies of these three herbs act via similar mechanism and whether they possess comparable therapeutic efficacy for experimental myocardial ischemia (MI).
The present study aimed to further investigate the underlying mechanisms with respect to antioxidative stress activity by which these Dioscorea spp. attenuate MI, and to compare the therapeutic effect of total saponins from these three species on myocardial antioxidant levels and myocardial histology.
The serum levels of creatine kinase (CK), lactate dehydrogenase (LDH), aspartate aminotransferase (AST), total superoxide dismutases (SOD), catalase (CAT), glutathione peroxidase (GPx), the total antioxidant capacity (T-AOC), and malondialdehyde (MDA), as well as myocardial histology, were compared among rat groups administered with total saponins (TS) of DN, DP or DZ (abbreviated as DNTS, DPTS and DZTS, respectively). The rats experienced myocardial ischemia induced by isoprenaline (ISO) injection; the test solutions (DNTS, DPTS, DZTS) were administered either after the ISO injection, or both before and after.
Compared with the model group (ISO injection only), TS groups exhibited significantly reduced activities of CK, LDH and AST, lowered level of MDA, and increased activities of SOD, CAT, GPx and T-AOC; heart tissues from TS groups revealed less severe histological damage. The cardioprotective efficacy of these three Dioscorea TS for rat MI was closely comparable based on the above observations.
The findings of the present study provide evidence that the anti-MI effect of DNTS, DPTS and DZTS can be attributed to the increase of myocardial antioxidant levels and decrease of lipid peroxidation formation, and the closely comparable results observed from these three Dioscorea saponins thereby explains the similarity in their clinical efficacy as anti-MI drugs.
自20世纪50年代起，穿龙薯蓣（DN）、黄山药（DP）和盾叶薯蓣（DZ）在中国被用作民间药物，它们被认为具有大致相同的传统治疗作用，如活血、止痛、消肿。值得注意的是，在中国分布的49种薯蓣属植物中，基于这些传统功效，只有这三种被现代制药行业进一步开发为治疗心血管疾病的有效单味药。在我们之前的研究中，发现穿龙薯蓣和黄山药的化学成分相似，且二者均与盾叶薯蓣不同。因此，它们不同的化学特征是否支持其共同的抗缺血性心脏病（IHD）活性仍有待解答。到目前为止，这三种草药的功效是否通过相似机制发挥作用以及它们对实验性心肌缺血（MI）是否具有相当的治疗效果仍不清楚。
本研究旨在进一步探究这些薯蓣属植物减轻心肌缺血的抗氧化应激活性的潜在机制，并比较这三种植物总皂苷对心肌抗氧化水平和心肌组织学的治疗效果。
比较给予穿龙薯蓣、黄山药或盾叶薯蓣总皂苷（分别简称为DNTS、DPTS和DZTS）的大鼠组之间血清肌酸激酶（CK）、乳酸脱氢酶（LDH）、天冬氨酸转氨酶（AST）、总超氧化物歧化酶（SOD）、过氧化氢酶（CAT）与谷胱甘肽过氧化物酶（GPx）水平、总抗氧化能力（T-AOC）以及丙二醛（MDA）水平，以及心肌组织学情况。大鼠通过注射异丙肾上腺素（ISO）诱导心肌缺血；受试溶液（DNTS、DPTS、DZTS）在ISO注射后给予，或在ISO注射前后均给予。
与模型组（仅注射ISO）相比，总皂苷组的CK、LDH和AST活性显著降低，MDA水平降低，SOD、CAT、GPx活性和T-AOC升高；总皂苷组的心脏组织显示出较轻的组织学损伤。基于上述观察结果，这三种薯蓣属植物总皂苷对大鼠心肌缺血的心脏保护功效相当。
本研究结果提供了证据，表明穿龙薯蓣总皂苷、黄山药总皂苷和盾叶薯蓣总皂苷的抗心肌缺血作用可归因于心肌抗氧化水平的提高和脂质过氧化形成的减少，并且从这三种薯蓣皂苷观察到的相当结果解释了它们作为抗心肌缺血药物临床疗效的相似性。
