Faculty of Health Sciences, Federal University of Grande Dourados, Rodovia Dourados - Itaúm, Km 12, Dourados, Mato Grosso do Sul 79804-970, Brazil.
BMC Complement Altern Med. 2014 Jun 28;14:209. doi: 10.1186/1472-6882-14-209.
The recent emergence of extensively multidrug-resistant Mycobacterium tuberculosis strains has further complicated the control of tuberculosis. There is an urgent need for the development of new molecular candidates antitubercular drugs. Medicinal plants have been an excellent source of leads for the development of drugs. The aim of this study was to evaluate the in vitro activity of 28 alcoholic extracts and essential oils of native and exotic Brazilian plants against Mycobacterium tuberculosis and to further study these extracts through chemical fractionation, the isolation of their constituents, and an evaluation of the in vivo acute toxicity of the active extracts. To the best of our knowledge this is the first chemical characterization, antituberculosis activity and acute toxicity evaluation of Annona sylvatica.
The anti-mycobacterial activity of these extracts and their constituent compounds was evaluated using the resazurin reduction microtiter assay (REMA). To investigate the acute toxicity of these extracts in vivo, female Swiss mice were treated with the extracts at doses of 500, 1000 and 2000 mg · kg(-1) of body weight. The extracts were characterized by LC-MS, and the constituents were isolated and identified by chromatographic analysis of spectroscopic data.
Of the 28 extracts, the methanol extract obtained from the leaves of Annona sylvatica showed anti-mycobacterial activity with an minimal inhibitory concentration (MIC) of 184.33 μg/mL, and the ethyl acetate fraction (EAF) resulting from liquid-liquid partitioning of the A. sylvatica extract showed an MIC of 115.2 μg/mL. The characterization of this extract by LC-MS identified flavonoids and acetogenins as its main constituents. The phytochemical study of the A. sylvatica EAF resulted in the isolation of quercetin, luteolin, and almunequin.
Among the compounds isolated from the EAF, luteolin and almunequin were the most promising, with MICs of 236.8 μg/mL (827.28 μM) and 209.9 μg/mL (328.48 μM), respectively. The acute administration of the EAF fraction in doses of 500, 1000, and 2000 mg · kg(-1) of body weight did not cause signs of toxicity in the treated animals.
广泛耐药结核分枝杆菌菌株的新近出现使结核病的控制更加复杂。迫切需要开发新的分子候选抗结核药物。药用植物一直是开发药物的极好的先导化合物来源。本研究的目的是评估 28 种来自巴西本土和外来植物的醇提物和精油对结核分枝杆菌的体外活性，并通过化学分段、分离其成分以及评估活性提取物的体内急性毒性进一步研究这些提取物。据我们所知，这是首次对番荔枝进行化学表征、抗结核活性和急性毒性评估。
使用 Resazurin 还原微量滴定法（REMA）评估这些提取物及其成分化合物的抗分枝杆菌活性。为了研究这些提取物在体内的急性毒性，用 500、1000 和 2000mg·kg(-1)体重的提取物处理雌性瑞士小鼠。通过 LC-MS 对提取物进行表征，并通过色谱分析和光谱数据对成分进行分离和鉴定。
在 28 种提取物中，从番荔枝叶中获得的甲醇提取物显示出抗分枝杆菌活性，最小抑菌浓度（MIC）为 184.33μg/mL，从番荔枝提取物液-液分配得到的乙酸乙酯馏分（EAF）显示 MIC 为 115.2μg/mL。通过 LC-MS 对该提取物进行的表征鉴定出黄酮类化合物和乙酰基原生物作为其主要成分。对番荔枝 EAF 的植物化学研究导致分离出槲皮素、木樨草素和 almunequin。
从 EAF 中分离出的化合物中，木樨草素和 almunequin 最有希望，MIC 分别为 236.8μg/mL（827.28μM）和 209.9μg/mL（328.48μM）。以 500、1000 和 2000mg·kg(-1)体重的剂量给予 EAF 馏分进行急性给药，在治疗动物中未引起毒性迹象。
