Antimicrobial and antioxidant activities of Pimenta malagueta (Capsicum frutescens)

Abstract

Pimenta malagueta (Capsicum frutescens), as it is known in Brazil, is one of the most commonly used pepper species in cooking and in Brazilian folk medicine. In this work, the total phenolic compounds and the capsaicin, dihydrocapsaicin, and chrysoeriol contents of C. frutescens were analysed. Additionally, the antioxidant and antimicrobial activities were determined. The contents of capsaicin, dihydrocapsaicin, and chrysoeriol found were 9.2, 4.0, and 2.1 mg/g extract, respectively. The minimal inhibitory concentration was determined against six strains of Gram positive and Gram negative bacteria species and one yeast strain (Candida albicans UFPEDA 1007), but for all of these microorganisms, the necessary concentrations were higher than 1000 µg/ml. The total phenolic content was 9.1 mg of gallic acid equivalent/g extract. The ethanolic extract of C. frutescens had effective 2,2-diphenyl-1-picrylhydrazyl (DPPH) ABTS• and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) ABTS•+ scavenging activities (EC50values of 302.3 and 82.6 g/ml, respectively), and the percentage of antioxidant activity determined using the β-carotene/linoleic acid assay ranged from 15 to 47%. The primary groups of compounds extracted from plants with biological properties are essential oils, alkaloids, glycosides, phenolic compounds, terpenoids, and flavonoids. Our results suggest that C. frutescens had a potential antimicrobial and antioxidant effect due to its content in phenolic, capsaicinoid, and flavonoid substances. Key words: DPPH, β-carotene/linoleic acid system, capsaicin, Capsicum frutescens.