School of Pharmacy and Pharmacology, Gold Coast Campus, Griffith University, Parklands Drive, Southport, Queensland, 4222, Australia; Menzies Health Institute Queensland, Quality Use of Medicines Network, Queensland, 4222, Australia.
School of Environment and Science, Nathan Campus, Griffith University, 170 Kessels Rd, Nathan, Queensland, 4111, Australia; Environmental Futures Research Institute, Nathan Campus, Griffith University, 170 Kessels Rd, Nathan, Queensland, 4111, Australia.
J Ethnopharmacol. 2020 Oct 5;260:112937. doi: 10.1016/j.jep.2020.112937. Epub 2020 May 25.
Triphala is used in Ayurveda to treat a wide variety of diseases, including numerous bacterial infections. Interestingly, the plant components of triphala (Terminalia bellirica, Terminalia chebula and Emblica officinalis) are also good inhibitors of bacterial growth when used individually, yet plant preparations are generally used in combination in traditional medicine. Surprisingly, no previous studies have addressed the reason why the combination is preferred over the individual components to treat bacterial infections.
To test and compare the antibacterial efficacy of triphala and its component parts to quantify their relative efficacies. The individual plant components will also be tested as combinations, thereby determining whether combining the individual components potentiates the antibacterial activity of the components used alone.
Triphala and the three individual plant components were extracted using solvents of varying polarity (methanol, water, ethyl acetate) and the antibacterial activity of the aqueous resuspensions was quantified by disc diffusion and broth microdilution MIC assays. Combinations of extracts produced from the individual components were also tested against each bacterial species and the ΣFICs was calculated to determine the class of interaction. Where synergy was detected, isobologram analysis was used to determine the optimal component ratios. The Artemia nauplii bioassay was used to test for toxicity and GC-MS headspace profiling analysis was used to highlight terpenoid components that may contribute to the antibacterial activity of triphala.
The aqueous and methanolic triphala, T. bellirica, T. chebula and E. officinalis extracts displayed good inhibitory activity against all bacterial strains, with MICs often in the 250-750 μg/mL range. The methanolic extracts were generally more potent than the aqueous extracts and T. chebula was the most potent of the individual plant components. Combining the extracts of the different plant species resulted in potentiation of the growth inhibitory activity of most combinations compared to that of the individual components. Indeed, with the exception of S. flexneri, all bacterial species were potentiated by at least one combination of methanolic plant extracts, with a substantial proportion of these displaying synergistic interactions. All extracts were found to be either non-toxic, or of low to moderate toxicity in Artemia nauplii assays.
Whilst the individual plant components of triphala all inhibit the growth of multiple pathogenic bacteria, the activity is potentiated for multiple combinations. Therefore, the traditional usage of the combination of the three plant materials in triphala not only extends the activity profile of the mixture over that of the individual components, but it also substantially potentiates the inhibitory activity towards multiple bacteria, partially explaining the preference of triphala compared to the individual components.
在阿育吠陀医学中，三果汤被用于治疗多种疾病，包括许多细菌感染。有趣的是，三果汤的植物成分（诃子、使君子和余甘子）在单独使用时也是很好的细菌生长抑制剂，然而植物制剂通常在传统医学中联合使用。令人惊讶的是，以前没有研究探讨为什么组合比单独使用成分更能治疗细菌感染。
测试和比较三果汤及其成分的抗菌功效，以量化它们的相对功效。还将测试单个植物成分的组合，从而确定组合使用单个成分是否增强了单独使用成分的抗菌活性。
使用不同极性的溶剂（甲醇、水、乙酸乙酯）提取三果汤和三种单个植物成分，并通过圆盘扩散和肉汤微量稀释 MIC 测定法定量测定水悬浮液的抗菌活性。还针对每种细菌对来自单个成分的提取物组合进行了测试，并计算了 ΣFIC 以确定相互作用的类别。当检测到协同作用时，使用棋盘微量稀释法分析确定最佳成分比例。使用卤虫幼虫生物测定法测试毒性，使用 GC-MS 顶空分析突出可能对三果汤抗菌活性有贡献的萜烯成分。
水提和甲醇提三果汤、诃子、使君子和余甘子提取物对所有细菌菌株均显示出良好的抑制活性，MIC 通常在 250-750μg/mL 范围内。甲醇提取物通常比水提取物更有效，使君子是单个植物成分中最有效的成分。与单独使用成分相比，组合使用不同植物物种的提取物通常会增强大多数组合的生长抑制活性。事实上，除了福氏志贺菌外，所有细菌物种都至少被一种甲醇植物提取物组合增强，其中很大一部分显示出协同作用。所有提取物在卤虫幼虫测定中均被发现无毒或低毒至中度毒性。
虽然三果汤的单个植物成分都能抑制多种致病性细菌的生长，但活性在多种组合中得到增强。因此，传统上使用三种植物材料的组合不仅扩展了混合物的活性谱，使其超过了单个成分的活性谱，而且还大大增强了对多种细菌的抑制活性，部分解释了三果汤比单个成分更受欢迎的原因。
