Phytochemical Analysis and Antibacterial Effects of Black Pepper (Piper nigrum L.) on Selected Bacteria Causing Urinary Tract Infections

Abstract

This study examined the bioactive ingredients and the antibacterial effects of methanolic seeds extract of Piper nigrum. The plant materials were collected, dried, pulverized and extracted using soxhlet apparatus. This was followed by qualitative and quantitative phytochemical analysis. Bacterial isolates were obtained from the laboratory and identified using cultural and biochemical methods. Agar well diffusion method was adopted the sensitivity testing where the MIC and MBC of the extracts were determined. The extract contained significantly higher concentration of tannins (57.671.53mg/g) than other constituents. Among the five species of bacteria isolated. the plant extract had pronounced effect on Proteus mirabilis at 100mg/ml and Staphylococcus. aureus at 100 and 50mg/ml. Bactericidal activity was slightly higher at 100mg/ml than 50mg/ml with no significant difference (P=0.695). The plant extract showed no activity on Escherichia coli and Pseudomonas aeruginosa. The established bactericidal action of the P. nigrum extracts could be exploited locally and industrially in the manufacture of cheap plant based sources of antibiotics against the bacteria found sensitive to the extract.