The in vitro evaluation of antibacterial and antifungal activities of ripe fruit extracts (pericarp and seed) of Bunchosia armeniaca (Cav.) DC.
Mackingsley Kushan Dassanayake

Plants are rich sources of phytoconstituents that has the ability to contribute biological activities. Indigenously prepared crude extracts of medicinal plants have been used as medications to treat infections caused by pathogenic microorganisms by people of various ethnic origins for many centuries in folkloric medicine. The research in discovering new and innovative antimicrobial compounds from plants has received increased concern due to the global rise of antimicrobial resistance. The present study aims to evaluate the in vitro antimicrobial potential of pericarp and seed extracts of ripe fruits associated with a native South American plant specimen known as Bunchosia armeniaca. The antibacterial and antifungal activities of aqueous and ethanolic crude extracts with concentrations ranging from 1000 to 125 μg/ml were determined against bacterial pathogens of Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa, Klebsiella pneumoniaeStreptococcus pyogenes, viridans group streptococci and fungal pathogens of Candida albicans and Aspergillus fumigates by performing the agar well diffusion assay. The pericarp extract did not exhibit any antimicrobial activity while the aqueous seed extract was only active against Escherichia coli which indicated a mean inhibition zone diameter of 16.2 mm at its highest concentration. The minimum inhibitory concentration of the seed extract was 250 μg/ml. The qualitative phytochemical analysis indicated the presence of flavonoids, phenols, tannins, alkaloids, phytosterols and saponins in both aqueous crude extracts. The findings of this investigation justifies that seeds of Bunchosia armeniaca ripe fruit has the ability to function as a novel, potent antibacterial therapeutic agent against multidrug resistant Escherichia coli.

Keywords: Bunchosia armeniaca; Antibacterial activity; minimum inhibitory concentration; agar well diffusion assay