Differences in Antibacterial Activity of Eight Medicinal and Edible Traditional Chinese Medicines Produced in Zhaoqing.

[Objectives] To study the differences in antibacterial activity of eight medicinal and edible traditional Chinese medicines Produced in Zhaoqing. [Methods] This study selected eight common medicinal and edible traditional Chinese herbs from Zhaoqing region (Centipeda minima, Lonicera japonica, Vitex negundo, Plantago asiatica, Houttuynia cordata, Hedyotis diffusa, Hylocereus undatus, and Bombax ceiba) to compare their antibacterial activity differences through in vitro antibacterial experiments, and explored the effects of extraction methods and different solvents. For H. undatus and B. ceiba, the antibacterial effects of decoction and ultrasound-assisted extraction on Escherichia coli and Staphylococcus aureus were compared. For H. diffusa and H. cordata, three different solvents (n-butanol, ethyl acetate, and dichloromethane) were used for extraction to analyze the influence of polarity on antibacterial activity (inhibition zone). The remaining four herbs were directly compared for the inhibitory differences of their crude extracts against Gram-positive bacteria. [Results] (i) The ultrasound-assisted extracts of H. undatus and B. ceiba exhibited significantly superior antibacterial effects compared to traditional decoction. (ii) The n-butanol extract of H. diffusa showed 7.5% and 4.5% higher inhibition rate against S. aureus than the ethyl acetate and dichloromethane extracts, respectively. The ethyl acetate extract exhibited weak inhibitory effects on E. coli, while extracts from other solvents showed no inhibition. The ethyl acetate extract of H. cordata demonstrated good inhibitory effects against both bacterial strains and outperformed the extracts of H. diffusa. (iii) The crude extracts of C. minima, L. japonica, V. negundo, and P. asiatica all exhibited good inhibitory effects against S. aureus, with C. minima showing the strongest antibacterial activity, Correlation analysis revealed a positive relationship between antibacterial effects and extract concentration. [Conclusions] This study provides optimization strategies for the differential extraction and antimicrobial applications of medicinal and edible herbs. [ABSTRACT FROM AUTHOR]