Unidad de Biotecnología del Centro de Investigación Científica de Yucatán A.C., Calle 43, No. 130, Col. Chuburná de Hidalgo, CP 97200 Mérida, Yucatán, Mexico.
División de Biología Celular y Molecular, Centro de Investigación Biomédica del Noreste, IMSS, San Luis Potosí y 2 de Abril, Col. Independencia, CP 65720 Monterrey, Nuevo León, Mexico.
Pulm Pharmacol Ther. 2014 Feb;27(1):114-20. doi: 10.1016/j.pupt.2013.08.001. Epub 2013 Aug 20.
The recent emergence of multidrug-resistant (MDR), extensively drug-resistant (XDR), and totally drug-resistant (TDR) Mycobacterium tuberculosis (MTB) strains have further complicated the control of tuberculosis (TB). There is an urgent need of new molecules candidates to be developed as novel, active, and less toxic anti-tuberculosis (anti-TB) drugs. Medicinal plants have been an excellent source of leads for the development of drugs, particularly as anti-infective agents. In previous studies, the non-polar extract of Diospyros anisandra showed potent anti-TB activity, and three monomeric and five dimeric naphthoquinones have been obtained. In this study, we performed bioguided chemical fractionation and the isolation of eight naphthoquinones from D. anisandra and their evaluation of anti-TB and cytotoxic activities against mammalian cells.
The n-hexane crude extract from the stem bark of the plant was obtained by maceration and liquid-liquid fractionation. The isolation of naphthoquinones was carried out by chromatographic methods and identified by gas chromatography and mass spectroscopy data analysis. Anti-TB activity was evaluated against two strains of MTB (H37Rv) susceptible to all five first-line anti-TB drugs and a clinical isolate that is resistant to these medications (pan-resistant, CIBIN 99) by measuring the minimal inhibitory concentration (MIC). Cytotoxicity of naphthoquinones was estimated against two mammalian cells, Vero line and primary cultures of human peripheral blood mononuclear (PBMC) cells, and their selectivity index (SI) was determined.
Plumbagin and its dimers maritinone and 3,3'-biplumbagin showed the strongest activity against both MTB strains (MIC = 1.56-3.33 μg/mL). The bioactivity of maritinone and 3,3'-biplumbagin were 32 times more potent than rifampicin against the pan-resistant strain, and both dimers showed to be non-toxic against PBMC and Vero cells. The SI of maritinone and 3,3'-biplumbagin on Vero cells was 74.34 and 194.11 against sensitive and pan-resistant MTB strains, respectively.
Maritinone and 3,3'-biplumbagin possess a very interesting potential for development as new drugs against M. tuberculosis, mainly resistant profile strains.
耐多药（MDR）、广泛耐药（XDR）和完全耐药（TDR）结核分枝杆菌（MTB）菌株的新近出现使结核病（TB）的控制更加复杂。迫切需要开发新的候选分子，作为新型、有效和低毒的抗结核（anti-TB）药物。药用植物一直是开发药物的极好来源，特别是作为抗感染药物。在以前的研究中，Diospyros anisandra 的非极性提取物表现出很强的抗结核活性，并且已经获得了三个单体和五个二聚体萘醌。在这项研究中，我们对 D. anisandra 进行了生物导向的化学分馏和分离，得到了八种萘醌，并对它们的抗结核活性和对哺乳动物细胞的细胞毒性进行了评价。
采用浸渍和液-液萃取法从植物茎皮中提取正己烷粗提取物。通过色谱方法分离萘醌，并通过气相色谱和质谱数据分析进行鉴定。通过测定最小抑菌浓度（MIC），对两种结核分枝杆菌（H37Rv）菌株（对所有五种一线抗结核药物敏感）和一种对这些药物耐药的临床分离株（泛耐药，CIBIN 99）进行抗结核活性评价。用两种哺乳动物细胞（Vero 细胞和人外周血单个核细胞（PBMC）的原代培养物）测定萘醌的细胞毒性，并确定其选择性指数（SI）。
白花丹醌及其二聚体马丁酮和 3,3'-双白花丹醌对两种 MTB 菌株均显示出最强的活性（MIC = 1.56-3.33 μg/mL）。马丁酮和 3,3'-双白花丹醌对泛耐药株的活性比利福平强 32 倍，而且这两种二聚体对 PBMC 和 Vero 细胞均无毒性。马丁酮和 3,3'-双白花丹醌对 Vero 细胞的选择性指数（SI）分别为敏感和泛耐药 MTB 菌株的 74.34 和 194.11。
马丁酮和 3,3'-双白花丹醌具有作为抗结核分枝杆菌新型药物开发的巨大潜力，特别是针对耐药性菌株。
