Department of Pharmaceutical Sciences, Faculty of Science, Tshwane University of Technology, Private Bag X680, Pretoria, 0001, South Africa.
Department of Pharmaceutical Sciences, Faculty of Science, Tshwane University of Technology, Private Bag X680, Pretoria, 0001, South Africa; SAMRC Herbal Drug Research Unit, Faculty of Science, Tshwane University of Technology, Private Bag X680, Pretoria, 0001, South Africa.
J Ethnopharmacol. 2021 Apr 6;269:113681. doi: 10.1016/j.jep.2020.113681. Epub 2020 Dec 9.
Many species within the family Combretaceae are popular medicinal plants that are used traditionally to treat various conditions, of which many are related to bacterial infections. Global concerns regarding the increasing resistance of pathogens towards currently available antibiotics have encouraged researchers to find new drugs with antibacterial activity, particularly from plant sources.
This study was aimed at exploring the broad-spectrum antibacterial potential of methanol extracts of species representing four genera of Combretaceae (Combretum, Pteleopsis, Quisqualis, Terminalia), indigenous to South Africa, using a biochemometric approach.
The microdilution assay was used to determine the antibacterial activities, measured as minimum inhibitory concentrations (MICs), of the 51 methanol extracts representing 35 Combretaceae species, against nine species of pathogenic bacteria. Integrative biochemometric analysis was performed, thereby correlating the MIC values with the metabolomic data obtained from ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) analysis. Orthogonal projections to latent structures-discriminant analysis (OPLS-DA) models were constructed for six pathogens displaying variation in their susceptibility towards the extracts.
Evaluation of the overall MIC values obtained indicated that extracts of species from the four genera displayed the highest activity towards Bacillus cereus ATCC 11778 (average MIC 0.52 mg/mL) and Salmonella typhimurium ATCC 14028 (average MIC 0.63 mg/mL). These bacteria were the most sensitive Gram-positive and Gram-negative bacteria, respectively. Extracts from Combretum acutifolium, Combretum imberbe and Combretum elaeagnoides were the most active, with average MIC values of 0.70 mg/mL, 0.52 mg/mL and 0.45 mg/mL, respectively. Five triterpenoid compounds were tentatively identified as biomarkers from the biochemometric analysis.
Correlation of the phytochemistry of species from four genera in the Combretaceae family with antibacterial activity revealed that triterpenoids are responsible for the broad-spectrum antibacterial activity observed.
Combretaceae 科的许多物种都是常用的药用植物，传统上用于治疗各种病症，其中许多与细菌感染有关。全球对病原体对抗生素耐药性不断增加的担忧促使研究人员寻找具有抗菌活性的新药，特别是来自植物来源的药物。
本研究旨在通过生化计量学方法探索南非本土四个 Combretaceae 属（Combretum、Pteleopsis、Quisqualis、Terminalia）的 35 种代表物种的甲醇提取物的广谱抗菌潜力。
使用微量稀释法测定 51 种甲醇提取物对 9 种致病菌的抗菌活性，以最小抑菌浓度（MIC）表示。进行综合生化计量学分析，将 MIC 值与超高效液相色谱-质谱（UPLC-MS）分析获得的代谢组学数据相关联。对 6 种对提取物敏感性不同的病原体构建正交投影到潜在结构判别分析（OPLS-DA）模型。
评估获得的总体 MIC 值表明，来自四个属的物种提取物对蜡状芽孢杆菌 ATCC 11778（平均 MIC 0.52mg/mL）和鼠伤寒沙门氏菌 ATCC 14028（平均 MIC 0.63mg/mL）显示出最高的活性。这两种细菌分别是最敏感的革兰氏阳性菌和革兰氏阴性菌。Combretum acutifolium、Combretum imberbe 和 Combretum elaeagnoides 的提取物最为活跃，平均 MIC 值分别为 0.70mg/mL、0.52mg/mL 和 0.45mg/mL。通过生化计量学分析，初步鉴定了 5 种三萜类化合物作为生物标志物。
将 Combretaceae 科四个属的物种的植物化学与抗菌活性相关联表明，三萜类化合物是观察到的广谱抗菌活性的原因。
