AIDS Virus Research Laboratory, Department of Microbiology, University of Venda, Thohoyandou 0950, South Africa.
BMC Complement Altern Med. 2011 Apr 11;11:28. doi: 10.1186/1472-6882-11-28.
Tuberculosis, caused by Mycobacterium tuberculosis (MTB), is the most notified disease in the world. Development of resistance to first line drugs by MTB is a public health concern. As a result, there is the search for new and novel sources of antimycobacterial drugs for example from medicinal plants. In this study we determined the in vitro antimycobacterial activity of n-Hexane sub-fraction from Bridelia micrantha (Berth) against MTB H37Ra and a clinical isolate resistant to all five first-line antituberculosis drugs.
The antimycobacterial activity of the n-Hexane sub-fraction of ethyl acetate fractions from acetone extracts of B. micrantha barks was evaluated using the resazurin microplate assay against two MTB isolates. Bioassay-guided fractionation of the ethyl acetate fraction was performed using 100% n-Hexane and Chloroform/Methanol (99:1) as solvents in order of increasing polarity by column chromatography and Resazurin microtiter plate assay for susceptibility tests.
The n-Hexane fraction showed 20% inhibition of MTB H37Ra and almost 35% inhibition of an MTB isolate resistant to all first-line drugs at 10 μg/mL. GC/MS analysis of the fraction resulted in the identification of twenty-four constituents representing 60.5% of the fraction. Some of the 24 compounds detected included Benzene, 1.3-bis (3-phenoxyphenoxy (13.51%), 2-pinen-4-one (10.03%), N(b)-benzyl-14-(carboxymethyl) (6.35%) and the least detected compound was linalool (0.2%).
The results show that the n-Hexane fraction of B. micrantha has antimycobacterial activity.
结核病是由结核分枝杆菌（MTB）引起的，是世界上报告最多的疾病。MTB 对一线药物产生耐药性是一个公共卫生问题。因此，人们一直在寻找新的、新颖的抗分枝杆菌药物来源，例如来自药用植物。在这项研究中，我们确定了 Bridelia micrantha（Berth）丙酮提取物的乙酸乙酯部分的正己烷亚馏分对 MTB H37Ra 和对所有五种一线抗结核药物均耐药的临床分离株的体外抗分枝杆菌活性。
使用 Resazurin 微量板测定法，评估来自 Bridelia micrantha 树皮的丙酮提取物的乙酸乙酯部分的正己烷亚馏分对两种 MTB 分离株的抗分枝杆菌活性。使用 100%正己烷和氯仿/甲醇（99:1）作为溶剂，通过柱层析和 Resazurin 微量板测定法进行生物测定指导的乙酸乙酯部分的分步分离，以增加极性。进行药敏试验。
正己烷馏分在 10μg/mL 时对 MTB H37Ra 的抑制率为 20%，对所有一线药物耐药的 MTB 分离株的抑制率接近 35%。该馏分的 GC/MS 分析导致鉴定出 24 种成分，占馏分的 60.5%。检测到的一些 24 种化合物包括苯、1,3-双（3-苯氧基苯氧基）（13.51%）、2-蒎烯-4-酮（10.03%）、N（b）-苄基-14-（羧甲基）（6.35%）和检测到的最少化合物是芳樟醇（0.2%）。
结果表明，Bridelia micrantha 的正己烷馏分具有抗分枝杆菌活性。
