Assessing the antimicrobial activity of Capsicum frutescens Linn. (Siling labuyo) crude fruit extract.

Abstract

Capsicum frutescens is the spiciest pepper cultivated in the Philippines. Capsaicin, comprising 90% of the phytochemicals found in its ripe fruits, is responsible for the antimicrobial activities of this species. This study aimed to determine the presence of the antimicrobial activity of the crude fruit extract of Capsicum frutescens on Staphylococcus aureus, Escherichia coli, Aspergillus fumigatus, and Alternaria alternata when introduced in varying concentrations and to compare the antimicrobial activity of C. frutescens with commercially available disinfectant (Zonrox). Crude ethanolic extracts were prepared, in different formulations (25%, 50%, 75%, and 100%), from ripe fruits of C. frutescens. The formulations of the crude extract were tested against the bacteria Staphylococcus aureus (UPCC 1143) and Escherichia coli (UPCC 1195) and fungi Aspergillus fumigata (ATCC 1028) and Alternaria alternata (ATCC 6663) using the disk diffusion method. Zonrox and deionized water served as the positive and negative controls, respectively. The extract inhibited the growth of S. aureus at 50% (0.84mm ± 0.31mm), 75% (1.1mm ± 0.17mm), and 100% (3.83mm ± 0.35mm) formulations. Also, it inhibited the growth of A. fumigatus at the 100% (0.63mm ± 0.20mm) formulation. A significant difference in the effectiveness of the different concentrations of Capsicum frutescens crude fruit extract against Staphylococcus aureus and Aspergillus fumigatus was observed. These results indicate that the effectiveness of the crude fruit extract against S. aureus and A. fumigatus is directly proportional to its concentration.