Objective: To evaluate the spectrum of antibacterial activity of plants growing in the central part of the Republic of Tajikistan.
Methods: The antibacterial properties of 18 plant species from the 14 families were studied. The extract samples on dry filter discs were prepared according to the method developed at Rutgers University. Screens-to-Nature (STN) and disc diffusion (DD) methods were used to assess antimicrobial properties of the extracts. The antimicrobial activity of plant extracts was determined against four types of pathogenic standard museum strains of Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, as well as by using the same types of microorganisms isolated from inpatients (the hospital strains).
Results: Ethanol extract from leaves of Artemisia absinthium demonstrated a broad-spectrum high degree of antimicrobial activity against both reference and hospital strains of S. aureus, P. aeruginosa and E. coli. The Morus nigra extract also showed broad-spectrum activity, however overall antibacterial activity was lower than in A. absinthium. In general, tested extracts were less effective against E. coli. None of the 18 tested extracts showed activity against K. pneumoniae.
Conclusions: Artemisia absinthium and Morus nigra have a broad-spectrum antimicrobial effect and differ only in the degree of activity. The extracts of Amaranthus tricolor and Arctium tomentosum, Indigofera tinctoria, Punica granatum were characterized by a somewhat narrower spectrum of action. Mentha arvensis and Allium suworowii had approximately the same degree of inhibitory ability.