Assessment of the antimicrobial activity of aqueous and ethanolic extracts of Piper guineense leaves

Abstract

The antimicrobial activity of aqueous and ethanolic extracts of leaves of Piper guineense was determined on some bacteria and fungi, namely, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, Candida albicans and Saccharomyces cerevisiae, using agar well diffusion method and minimum inhibitory concentration (MIC). The ethanolic extract was found to show more activity than the aqueous extract on all the isolates. The diameter of zones of inhibition for the ethanolic extract ranged between 2 and 12 mm, while that of aqueous extract ranged between 5 and 8 mm. The MIC of the ethanolic extract was from 2.5 to 10 mg/ml, while for aqueous extract, the MIC was 10 to 20 mg/ml. Escherichia coli was found to show the greatest sensitivity, while P. aeruginosa showed the least sensitivity of all the isolates. The phytochemical analysis carried out on P. guineense leaves revealed the presence of alkaloids, tannins, saponins, glycosides and flavonoids. The presence of these phytochemicals supports the use of this plant as antimicrobial agent. P. guineense can therefore be used as antimicrobial agent.

Evaluation of the Extracts of Piper guineense for Antibacterial Activity Against Spoilage Bacteria of Rivers State ‘Native’ Soup.

“…This finding is not in agreement with Ebana et al [12] who reported the inability of ethanolic extract of P. guineense to inhibit P. aeruginosa, while aqueous extract did. Aboaba et al [15] and Anyanwu and Nwosu [11] however, reported the inhibition of P. aeruginosa by both the aqueous and ethanol extract of P. guineense, with the ethanol zones of inhibition comparable to the finding of this study. The finding of this study is in agreement with reports by Osuala and Anyadoh [34] that methanolic extracts of P. guineense exhibited much more antibacterial activity against P. aeruginosa than the ethanolic extracts, recommending that methanol be used in preference to ethanol in extracting active ingredients from plants.…”

Evaluation of Heavy Metals Content and Human Health Risk Assessment via Consumption of Vegetables from Selected Markets in Bayelsa State, Nigeria

“…Hazard index was calculated as the sum of hazard quotients (HQs) [13][14][15][16]. Since different pollutants can cause similar adverse health effects, it is often appropriate to combine HQs associated with different substances [17][18][19][20][21].…”

Antioxidant and antimicrobial studies on fused-ring pyrazolones and isoxazolones

“…Compounds 20 and 26 showed significant activities against B. subtilis and C. albicans, MIC = 0.313-1.25 lg/mL, where the activity of pyrazolinones 20 was better than that of isoxazolinone 26. Antifungal activities were also shown by compounds 13,14,17,19,21,23, and 25, with 8-11 mm inhibition zones.…”

“…Agar well diffusion method was used for initial screening at concentrations of 100 lg/mL. 23,24 Minimum inhibitory concentrations (MIC) were determined for samples which showed activity. 23,24 Gram-positive organisms (Staphylococcus aureus ATCC 25923, Bacillus subtilis NCIB 3610), Gram-negative organisms (Pseudomonas aeruginosa NCIMB 8295, Escherichia coli ATCC 8739) and a fungal yeast Candida albicans were obtained and confirmed at the Microbiology Laboratory, Department of Biological Sciences, University of Botswana.…”