Antimicrobial activity of Mystroxylon aethiopicum and Psidium guajava leaves on selected pathogenic bacteria

Abstract

With the rise of antimicrobial resistance, the urge of having new lead compounds that could inhibit microbial growth is turning into a truth. The aim of the present investigation was to determine the antimicrobial activity of Mystroxylon aethiopicum and Psidium guajava on selected pathogenic bacteria. Extraction with petroleum ether and methanol was performed on both leaf powders. Agar well diffusion technique was followed. All the experiments were carried out in duplicate, and the results were analyzed by SPSS. Glycosides, tannins, saponins, flavonoids, and phenols were seen in both plants. However, alkaloids were only observed in P. guajava. Extracts showed various activities against tested bacteria. P. guajava methanol leaf extracts exhibited the greatest inhibitory activity against all the tested bacteria. The methanol and petroleum ether leaf extracts of M. aethiopicum had no effect on S. pneumonia and E. coli. P. guajava methanol extract had the lowest minimum inhibitory concentration of 50 mg/ml against S. aureus and K. oxytoca. 75 mg/ml was recorded for M. aethiopicum methanol leaf extract against K. oxytoca and S. aureus. The combination of the two extracts also showed a reduced of antimicrobial effect.