Antibacterial and antifungal activity of Combretum farinosum Kunth and Combretum igneiflorum Rendón & R. Delgad. extracts

Abstract

Infectious diseases like bacterial, fungal, viral are the top killers of a third of the world population. Limited access to comprehensive treatment forces people to rely on herbal concoctions for treatment. Combretum farinosum Kunth and C. igneiflorum Rendón & R. Delgad. are two similar vine plant species that have insufficient scientific investigation. The purpose of the study is to determine the in vitro antimicrobial activity of crude extracts of different parts of Combretum igneiflorum (roots, stem, and leaves) and Combretum farinosum (roots, fruits, leaves, and stem) using petroleum ether, acetone, and ethanol-water. The crude extract was tested against food-borne pathogens. Twenty-seven crude extracts were prepared from C. igneiflorum (roots, stem, and leaves) and C. farinosum (roots, stem, leaves, and fruits) and screened for their antimicrobial activity against four Gram-positive bacteria (Enterococcus faecalis, Staphylococcus aureus, Staphylococcus aureus methicillin resistant, Bacillus subtilis), four Gram-negative bacteria (Salmonella enteritidis, Pseudomonas aeruginosa, Shigella flexneri, and Escherichia coli B), and one fungus species (Candida albicans) using agar disc-diffusion, and microbroth dilution assays. Results show that crude extracts of both plants tested had broad antimicrobial activity. The minimum inhibitory concentration (MIC) of C. farinosum extract against tested bacteria ranged from 0.32 to 100 mg/ml, whereas C. igneiflorum extracts that showed antibacterial activity ranged from 2.5 to 75 mg/ml. Gram-positive bacteria tested were more susceptible to the extracts than gram-negative bacteria. Crude extracts of C. igneiflorum and C. farinosum have broad antimicrobial activity against the microbes tested.
 Keywords: Combretum farinosum Kunth, Combretum igneiflorum Rendón & R. Delgad. MTT, Minimum Inhibitory Concentration (MIC), Antifungal, Antibacterial.