Phytomedicine Programme, Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort 0110, South Africa.
J Ethnopharmacol. 2012 Oct 11;143(3):826-39. doi: 10.1016/j.jep.2012.08.004. Epub 2012 Aug 13.
Many Bauhinia species, including those indigenous to South Africa, are used in traditional medicine across the world for treating ailments such as gastrointestinal tract (GIT) disorders, diabetes, infectious diseases and inflammation.
Several relevant aspects of different fractions of leaf extracts of Bauhinia bowkeri (BAB), Bauhinia galpinii (BAG), Bauhinia petersiana (BAP), and Bauhinia variegata (BAV) used in South African traditional medicine to alleviate diarrhoea related symptoms were evaluated.
The antioxidative activities of the extracts were determined using the 2, 2-diphenyl-1-picrylhydrazyl (DPPH), 2, 2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid (ABTS(+)) radical scavenging and ferric reducing antioxidant power (FRAP) methods. In vitro antimicrobial activities of the extracts were determined against bacterial strains (Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and Enterococcus faecalis) and clinical isolates of the opportunistic fungal strains (Aspergillus fumigatus, Candida albicans, and Cryptococcus neoformans) using a serial dilution microplate method. The polyphenolic contents were quantified using standard methods, and anti-inflammatory activities of the crude extracts were determined using the cyclooxygenase and soybean 15-lipoxygenase enzyme inhibitory assays. The safety of the extracts was evaluated by determining the cytotoxicity against Vero cell lines.
The acidified 70% acetone crude extract and their fractions had good antiradical potency against the DPPH and ABTS radicals. The methanol soluble portions of the butanol fractions were more potent (EC(50) ranges from 0.64 ± 0.05 to 1.51 ± 0.07 and 0.88 ± 0.18 to 1.49 ± 0.09 μg/ml against DPPH and ABTS radical respectively) compared to the standard, trolox and ascorbic acid (EC(50) ranges from 1.47 ± 0.24 to 1.70 ± 0.27 μg/ml) for both DPPH and ABTS. The crude extracts contained variable quantities of phenolic content. The crude extracts and their fractions had weak to good antimicrobial activities, inhibiting the growth of the organisms at concentrations ranging from 39 to 2500 μg/ml. The BAG crude extract and its fractions were the most active against the fungi (MICs ranging from 39 to 625 μg/ml) while the BAB extract and its fractions were the least active with the MICs ranging between 39 and 2500 μg/ml. Aspergillus fumigatus was the least susceptible fungus while Cryptococcus neoformans was the most susceptible. The phenolic-rich crude extracts of BAB, BAG, and BAP had moderate to good dose-dependent cyclooxygenase-1 enzyme inhibitory activity with inhibitions between 22.8% and 71.4%. The extracts were however, inactive against cyclooxygenase-2. The extracts had some level of cytotoxicity towards Vero cell lines, reducing cell viability to less than 10% at concentrations more than 50 μg/ml.
The biological activities observed in Bauhinia species provide a scientific basis for the use of the plants in traditional medicines to treat diseases with multi-factorial pathogenesis such as diarrhoea, with each aspect of activity contributing to the ultimate therapeutic benefit of the plants. However, the use of the phenolic-rich extracts of these plants to treat diarrhoea or any other ailments in traditional medicine needs to be monitored closely because of potential toxic effects and selective inhibition of COX-1 with the associated GIT injury.
许多羊蹄甲属植物，包括南非土生土长的植物，在世界各地的传统医学中被用于治疗胃肠道（GIT）疾病、糖尿病、传染病和炎症等疾病。
评估南非传统医学中使用的羊蹄甲属植物（Bauhinia bowkeri（BAB）、Bauhinia galpinii（BAG）、Bauhinia petersiana（BAP）和Bauhinia variegata（BAV）叶提取物的不同部分缓解腹泻相关症状的几个相关方面。
使用 2,2-二苯基-1-苦基肼（DPPH）、2,2'-联氮-双（3-乙基苯并噻唑啉-6-磺酸）（ABTS（+））自由基清除和铁还原抗氧化能力（FRAP）方法测定提取物的抗氧化活性。采用连续稀释微量板法测定提取物对细菌株（金黄色葡萄球菌、铜绿假单胞菌、大肠杆菌和粪肠球菌）和临床分离的机会性真菌株（烟曲霉、白色念珠菌和新型隐球菌）的体外抗菌活性。使用标准方法定量多酚含量，并通过环氧化酶和大豆 15-脂氧合酶酶抑制测定法测定粗提取物的抗炎活性。通过测定对 Vero 细胞系的细胞毒性来评估提取物的安全性。
酸化的 70%丙酮粗提物及其馏分对 DPPH 和 ABTS 自由基具有良好的抗自由基活性。丁醇馏分的甲醇可溶部分更为有效（EC（50）范围分别为 0.64 ± 0.05 至 1.51 ± 0.07 和 0.88 ± 0.18 至 1.49 ± 0.09 μg/ml，分别针对 DPPH 和 ABTS 自由基）与标准品、trolox 和抗坏血酸（EC（50）范围分别为 1.47 ± 0.24 至 1.70 ± 0.27 μg/ml）相比。粗提取物含有不同数量的酚类含量。粗提取物及其馏分具有弱至强的抗菌活性，在 39 至 2500 μg/ml 的浓度范围内抑制了生物的生长。BAG 粗提取物及其馏分对真菌的活性最高（MIC 范围为 39 至 625 μg/ml），而 BAB 提取物及其馏分的活性最低，MIC 范围为 39 至 2500 μg/ml。烟曲霉是最不易受感染的真菌，而新型隐球菌是最易受感染的真菌。BAB、BAG 和 BAP 的富含酚类的粗提取物具有中等至良好的剂量依赖性环氧化酶-1 酶抑制活性，抑制率为 22.8%至 71.4%。然而，提取物对环氧化酶-2 没有活性。提取物对 Vero 细胞系具有一定程度的细胞毒性，在浓度超过 50 μg/ml 时，细胞活力降低到低于 10%。
羊蹄甲属植物中观察到的生物活性为植物在传统医学中用于治疗具有多因素发病机制的疾病（如腹泻）提供了科学依据，每种活性都有助于植物的最终治疗益处。然而，由于潜在的毒性作用和 COX-1 的选择性抑制与相关的胃肠道损伤，需要密切监测这些植物中富含酚类的提取物用于治疗腹泻或传统医学中的任何其他疾病。
