Eleutherine americana extract inhibits adherence to and invasion of Caco‐2 cells by commonly contaminated Campylobacter spp. in food

Abstract

Eleutherine americana, a well-known Asian medicinal herb, has been claimed for many biological activities. In this study, potential of E. americana ethanolic extract against adhesion and invasion of Caco-2 cells by commonly contaminated Campylobacter spp. was evaluated. MIC50 values of E. americana extract against 39 enteritis patient and 26 chicken isolates were 125 µg/ml. Two models were set up: Model I, Prevention: Preincubation of E. americana extract with campylobacters before adding to Caco-2 cells. Adhesion to and invasion of Caco-2 cells by campylobacters were completely inhibited within 12 hr. Model II, Treatment: Preincubation of the organisms with Caco-2 cells before adding the extract. Adding the extract after the bacteria were mixed with Caco-2 cells resulted in moderate effect on adhesion, but complete prevention of penetration of the organisms into Caco-2 cells was observed. The extract at the highest concentration tested (250 μg/ml) demonstrated no cytotoxicity toward Caco-2 cells. Practical applications Eleutherine americana bulb extract could be applied as an effective food preservative to control campylobacter contamination at initial stage in food chain. In addition, the extract provides a curative approach to campylobacter infections.