来自诃子和使君子的抗疟有效提取物和馏分。
Potent antiplasmodial extracts and fractions from Terminalia mantaly and Terminalia superba.
机构信息
Antimicrobial and Biocontrol Agents Unit, Laboratory for Phytobiochemistry and Medicinal Plants Studies, Faculty of Science, University of Yaoundé I, P.O. Box 812, Yaoundé, Cameroon.
Malaria Research Laboratory, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India.
出版信息
Malar J. 2018 Apr 3;17(1):142. doi: 10.1186/s12936-018-2298-1.
BACKGROUND
The emergence and spread of malaria parasites resistant to artemisinin-based combination therapy stresses the need for novel drugs against malaria. Investigating plants used in traditional medicine to treat malaria remains a credible option for new anti-malarial drug development. This study was aimed at investigating the antiplasmodial activity and selectivity of extracts and fractions from Terminalia mantaly and Terminalia superba (Combretaceae) that are used in Cameroon to treat malaria.
METHODS
Twelve methanolic (m) and water (w) extracts obtained by maceration of powdered dried leaves (l), stem bark (sb) and root (r) of Terminalia mantaly (Tm) and Terminalia superba (Ts) and 12 derived fractions of hexane, chloroform, ethyl acetate and 4 final residues of selected extracts were assessed for antiplasmodial potential in vitro against the chloroquine-resistant PfINDO and the chloroquine-sensitive Pf3D7 strains of Plasmodium falciparum using the SYBR green I-based fluorescence assay. The cytotoxicity of potent extracts and fractions was evaluated in vitro using the MTT assay on HEK239T cell line.
RESULTS
The antiplasmodial IC of extracts from both plants ranged from 0.26 to > 25 µg/mL. Apart from the extracts Tmrm and Tsrw that exerted moderate antiplasmodial activities (IC: 5-20 µg/mL) and Tmrw that was found to be non-active at the tested concentrations (IC > 25 µg/mL), all other tested crude extracts exhibited potent activities with IC < 5 µg/mL. The aqueous extracts from the stem bark of Terminalia mantaly (Tmsbw) and the leaf of Terminalia superba (Tslw) displayed the highest antiplasmodial activities (IC: 0.26-1.26 µg/mL) and selectivity (SI > 158) on both resistant PfINDO and sensitive Pf3D7 strains. Four fractions upon further extraction with chloroform and ethyl acetate (TmlwChl, TmsbwChl, TmsbwEA, TsrmEA) afforded from three selected crude extracts (Tmlw, Tmsbw, Tsrm) exhibited highly potent activities against both P. falciparum strains (IC < 2 µg/mL) and high selectivity (SI > 109).
CONCLUSIONS
The results achieved in this work validate the reported traditional use of Terminalia mantaly and Terminalia superba to treat malaria. Moreover, the highly potent and selective fractions warrant further investigation to characterize the active antiplasmodial principles and progress them to rodent malaria models studies if activity and selectivity are evidenced.
背景
疟原虫对青蒿素类复方疗法的耐药性的出现和传播，强调了有必要开发新的抗疟药物。研究用于治疗疟疾的传统医学中的植物仍然是开发新抗疟药物的一个可靠选择。本研究旨在研究在喀麦隆用于治疗疟疾的诃子属曼塔利（Terminalia mantaly）和诃子属超级（Terminalia superba）（使君子科）的提取物和馏分的抗疟原虫活性和选择性。
方法
用甲醇（m）和水（w）对 Terminalia mantaly（Tm）和 Terminalia superba（Ts）的粉末干燥叶（l）、茎皮（sb）和根（r）进行浸提，得到 12 种提取物，并衍生出 12 种正己烷、氯仿、乙酸乙酯馏分和 4 种选定提取物的最终残渣，采用 SYBR 绿 I 荧光法检测这些提取物和馏分对氯喹抗性 PfINDO 和氯喹敏感 Pf3D7 株疟原虫的抗疟原虫活性。采用 MTT 测定法在 HEK239T 细胞系上评估有潜在作用的提取物和馏分的细胞毒性。
结果
两种植物的提取物的抗疟原虫 IC 范围为 0.26 至 >25µg/mL。除了对两种疟原虫株均表现出中等抗疟原虫活性的 Tmrm 和 Tsrw 提取物（IC：5-20µg/mL）和在测试浓度下未发现活性的 Tmrw 提取物（IC >25µg/mL）外，所有其他测试的粗提物均表现出强活性，IC <5µg/mL。诃子属曼塔利的茎皮提取物（Tmsbw）和诃子属超级的叶提取物（Tslw）的水提取物（IC：0.26-1.26µg/mL）对两种耐药 PfINDO 和敏感 Pf3D7 株均表现出最高的抗疟原虫活性和选择性（SI >158）。从三种选定的粗提取物（Tmlw、Tmsbw、Tsrm）中进一步用氯仿和乙酸乙酯提取的 4 个馏分（TmlwChl、TmsbwChl、TmsbwEA、TsrmEA）对两种疟原虫株均表现出很强的活性（IC <2µg/mL）和高选择性（SI >109）。
结论
本研究结果验证了诃子属曼塔利和诃子属超级用于治疗疟疾的传统用途。此外，如果活性和选择性得到证实，高活性和选择性的馏分值得进一步研究以鉴定活性抗疟原虫成分，并将其推进到啮齿动物疟疾模型研究中。
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