Synergistic Effects of n-Hexane Fraction of Parkia biglobosa (Jacq.) Bark Extract and Selected Antibiotics on Bacterial Isolates

Abstract

Abstract:The incidence of resistance to commonly used antimicrobial agents by microbial pathogens demands increased effort in the development of effective ways of treating infections and diseases. The n-hexane fraction of lyophilized crude bark extract of Parkia biglobosa (Jacq.) was prepared and, in combination with selected antibiotics, assayed for antimicrobial activity against some selected bacterial pathogens using time-kill assay. Protein leakage analysis of the combined agents was performed using Bradford protein quantification method. Determination of active compounds present in the n-hexane fraction was done using Fourier Transform Infrared Spectroscopy (FTIR). While time-kill assay detected 43.33% synergy; 56.67% indifference and no antagonism at 1/2 × minimum inhibitory concentration (MIC), 1 × MIC exhibited 55% synergy, 45% indifference and no antagonism. Protein leakages from the cells of selected bacteria ranged from 1.20 µg/mL to 256.93 µg/mL. The presence of a phenyl group, an aromatic ring and phenolic compounds in the n-hexane fraction was confirmed at 2162 cm −1 -2020 cm −1 , 1605 cm −1 -1533 cm −1 and 1438 cm −1 -1444 cm −1 spectra peaks, respectively. The observed antibiotic−n-hexane fraction synergistic interaction revealed the improved antibacterial activity of the selected antibiotics. Hence, exploration of a combination of antibiotics with plant secondary metabolites is hereby advocated in the global quest for means of combating infectious diseases caused by multidrug-resistant pathogens.

Antibacterial and Antioxidant Activities of Dacryodes edulis Methanolic Leaf Extract

“…The filtrate collected was concentrated in vacuo in a rotary evaporator and then lyophilized. The resultant powder was kept in air-tight bottle and stored at 4°C in the refrigerator for further use [12].…”

Chemical Composition, Antimicrobial Activity, and Antioxidant Activity of Ocotea minarum (Nees & Mart.) Mez.

“…These compounds are described as having various biological activities, including antimicrobial action. Microbial infections are growing at an alarming level [4, 5] owing to the ability of bacteria and yeasts to acquire and transmit genetic resistance material, leading to the constant evolution of multidrug-resistant microorganisms that threaten public health [6–8]. In this milieu, medicinal plants are receiving special attention for the development of new antimicrobial agents due to their therapeutic activity, low toxicity, and economic viability when compared with those of traditional allopathic compounds [9, 10].…”