Abstract：
OBJECTIVE: The research aimed to optimize the ultrasound-assisted extraction of secondary metabolites and the antibacterial activity of the plant species Geranium robertianum. The phytochemical profiles of the optimized extracts, as well as their antibacterial and synergistic activity with an antibiotic and their potential mechanisms of action and cytotoxicity, were examined.
RESULTS: Response Surface Methodology was used to optimize extraction conditions. Optimized ethanol and acetone extracts were tested via microdilution, checkerboard, time-kill kinetics, and cell membrane permeability methods. The extracts displayed broad antibacterial activity with minimum inhibitory concentrations ranging from 1.25 to 20 mg ml-1. In addition, the extract synergistically reacted with gentamicin against gentamicin-resistant strains of Escherichia coli and Staphylococcus aureus, enhancing the efficacy of the antibiotic up to 32-fold. The extracts demonstrated strain-dependent bactericidal activity in a 24-h time interval. They increase the permeability of the cell membrane, thus disrupting its normal functioning. The cytotoxic concentration (CC50) on human keratinocytes was 1771.24 ± 5.78 µg ml-1 for ethanol extract, and 958.01 ± 6.14 µg ml-1 for acetone extract. Kaempferol, ellagic acid, quercetin, and rutin were recognized as the main components in both extracts.
CONCLUSIONS: The findings of this study indicate that the extracts of G. robertianum can be considered as potential natural antibacterial agents in the control of microorganisms.
RESULTS: Response Surface Methodology was used to optimize extraction conditions. Optimized ethanol and acetone extracts were tested via microdilution, checkerboard, time-kill kinetics, and cell membrane permeability methods. The extracts displayed broad antibacterial activity with minimum inhibitory concentrations ranging from 1.25 to 20 mg ml-1. In addition, the extract synergistically reacted with gentamicin against gentamicin-resistant strains of Escherichia coli and Staphylococcus aureus, enhancing the efficacy of the antibiotic up to 32-fold. The extracts demonstrated strain-dependent bactericidal activity in a 24-h time interval. They increase the permeability of the cell membrane, thus disrupting its normal functioning. The cytotoxic concentration (CC50) on human keratinocytes was 1771.24 ± 5.78 µg ml-1 for ethanol extract, and 958.01 ± 6.14 µg ml-1 for acetone extract. Kaempferol, ellagic acid, quercetin, and rutin were recognized as the main components in both extracts.
CONCLUSIONS: The findings of this study indicate that the extracts of G. robertianum can be considered as potential natural antibacterial agents in the control of microorganisms.
摘要：
目的：本研究旨在优化植物天竺葵次生代谢产物的超声辅助提取和抑菌活性。优化提取物的植物化学概况，以及它们与抗生素的抗菌和协同活性，它们潜在的作用机制和细胞毒性，进行了检查。
结果：采用响应面法优化提取条件。通过微量稀释测试优化的乙醇和丙酮提取物，棋盘,时间杀伤动力学和细胞膜通透性方法。提取物显示出广泛的抗菌活性，最小抑制浓度为1.25至20mgml-1。此外,该提取物与庆大霉素对大肠杆菌和金黄色葡萄球菌的庆大霉素抗性菌株的协同反应,将抗生素的功效提高高达32倍。提取物在24小时的时间间隔内表现出菌株依赖性杀菌活性。它们增加细胞膜的通透性，从而破坏其正常功能。对于乙醇提取物，人角质形成细胞的细胞毒性浓度（CC50）为1771.24±5.78µgml-1，和958.01±6.14µgml-1的丙酮提取物。山奈酚,鞣花酸,槲皮素,和芦丁被认为是两种提取物的主要成分。
结论：这项研究的结果表明，龙胆草的提取物可以被认为是控制微生物的潜在天然抗菌剂。
结果：采用响应面法优化提取条件。通过微量稀释测试优化的乙醇和丙酮提取物，棋盘,时间杀伤动力学和细胞膜通透性方法。提取物显示出广泛的抗菌活性，最小抑制浓度为1.25至20mgml-1。此外,该提取物与庆大霉素对大肠杆菌和金黄色葡萄球菌的庆大霉素抗性菌株的协同反应,将抗生素的功效提高高达32倍。提取物在24小时的时间间隔内表现出菌株依赖性杀菌活性。它们增加细胞膜的通透性，从而破坏其正常功能。对于乙醇提取物，人角质形成细胞的细胞毒性浓度（CC50）为1771.24±5.78µgml-1，和958.01±6.14µgml-1的丙酮提取物。山奈酚,鞣花酸,槲皮素,和芦丁被认为是两种提取物的主要成分。
结论：这项研究的结果表明，龙胆草的提取物可以被认为是控制微生物的潜在天然抗菌剂。
