Antibacterial Activity of Ethanolic and Aqueous Extracts of Echium amoenum Against Human and Plant Pathogenic Bacteria

Authors
Shabnam Golbouy Daghdari 1
Talieh Archin 2
Sina Fajri 1
Fatemeh Karbasi 1
1 Department of microbiology, School of Agriculture, Afagh Higher Education Institute, Urmia, Iran.
2 Department of microbiology, Zand Institute of Higher Education, Shiraz, Iran.
10.22034/zmm.2025.735913
Abstract
Echium amoenum is a traditional medicinal plant that has been used for its therapeutic properties, yet its antibacterial potential remains insufficiently studied. This research aimed to evaluate the antibacterial activity of ethanolic and aqueous extracts of E. amoenum against human pathogens (Staphylococcus aureus, Salmonella Typhi, Escherichia coli) and plant pathogens (Brenneria nigrifluens, Erwinia amylovora, Serratia marcescens, Pseudomonas syringae). Extracts were prepared by maceration and tested at concentrations of 50, 100, and 200 mg/mL using the agar well diffusion method. Both ethanolic and aqueous extracts exhibited dose-dependent inhibitory effects, with significantly larger inhibition zones at higher concentrations. The ethanolic extract showed stronger antibacterial activity compared to the aqueous extract. At 200 mg/mL, inhibition zones reached up to 21.6 mm for S. marcescens and 19.3 mm for E. amylovora, while B. nigrifluens and E. coli displayed the lowest susceptibility (7.6 mm and 12.6 mm, respectively). These findings indicate that E. amoenum, particularly its ethanolic extract, possesses considerable antibacterial potential against both human and plant pathogens. The results highlight its possible applications as a natural antimicrobial agent in medicine and agriculture, providing an alternative to synthetic antibiotics and chemical bactericides. Further in vivo and mechanistic studies are recommended to validate these effects and explore practical applications.
Keywords
Echium amoenum
antibacterial activity
aqueous extract
ethanolic extract
human pathogens
plant pathogens
Zand Molecular Microbiology
Volume 1, Issue 2
Autumn 2025
Pages 98-103