Evaluation of Antimicrobial Activity of Ethanolic Extract Derived From Leaves of Ficus Cyathistipula Warb. (Moraceae)

Abstract

Purpose: We continue our investigations regarding assessing the antibacterial and antioxidant properties of extracts derived from the leaves of various plants belonging to the Ficus genus. In the current study, we aimed to assess the antibacterial properties of ethanolic extract prepared from leaves of Ficus cyathistipula Warb. against some Gram-positive and Gram-negative bacteria to evaluate the possible use of this plant in the prevention and treatment of bacterial infections caused by these bacteria. Methodology. The leaves of F. cyathistipula were sampled at M.M. Gryshko National Botanic Garden (NBG, Kyiv, Ukraine) and the Botanic Garden of Ivan Franko National University in Lviv (Lviv, Ukraine). Freshly collected leaves were washed, weighed, and homogenized in 96% ethanol (in the proportion of 1:9, w/w) at room temperature. The extract was then filtered and investigated for its antimicrobial activity. The testing of the antibacterial activity of the plant extract was carried out in vitro by the Kirby-Bauer disc diffusion technique. Gram-negative bacteria, Pseudomonas aeruginosa (Schroeter) Migula (ATCC®27853™), Escherichia coli (Migula) Castellani and Chalmers (ATCC®35218™), and Escherichia coli (Migula) Castellani and Chalmers (ATCC®25922™), as well as Gram-positive bacteria Staphylococcus aureus subsp. aureus strain (ATCC®25923™), Staphylococcus aureus subsp. aureus strain (ATCC®29213™) and methicillin-resistant Staphylococcus aureus (NEQAS 3679™), as well as the fungus Candida albicans locally isolated, were used as test organisms. Zone diameters were determined and averaged. The following zone diameter criteria were used to assign susceptibility or resistance of bacteria to the phytochemicals tested: Susceptible ≥ 15 mm, Intermediate = 10–15 mm, and Resistant ≤ 10 mm. Scientific novelty. The ethanolic extract derived from the leaves of F. cyathistipula exhibited varying inhibitory activities against all the test strains. More sensitive for this extract was C. albicans strain. S. aureus subsp. aureus strain (ATCC® 25923™), S. aureus subsp. aureus strain (ATCC® 29213™), methicillin-resistant S. aureus (NEQAS 3679™), P. aeruginosa (Schroeter) Migula (ATCC® 27853™), E. coli (Migula) Castellani and Chalmers (ATCC® 25922™), and E. coli (Migula) Castellani and Chalmers (ATCC® 35218™) strains were more resistant to F. cyathistipula extract. The results are encouraging enough to pursue bioactivity-guided fractionation of this extract and structure elucidation of the active phytoconstituents from the F. cyathistipula extract as a possible anti-bacterial agent. Conclusions. S. aureus and C. albicans appeared to be more sensitive to the F. cyathistipula extract. The antibacterial activity may be associated with the presence of secondary metabolites. The results of this study provide baseline information on F. cyathistipula potential validity in the treatment of fungus-induced and bacterial infections, caused by Candida albicans and Staphylococcus aureus.