Antibacterial and anthelmintic activities of Xanthium strumarium (Asteraceae) extracts

Abstract

Plants of the Asteraceae family are broadly used against microorganisms pathogenic to people and animals, although their potential has not been studied completely so far. In an in vitro experiment, we tested ethanolic, ethyl-ether, and dimethyl-sulfoxide extracts from the fruits, leaves, shoots, and roots of Xanthium strumarium L. for their effects on 13 species of bacteria and larvae of 3 species of nematodes. Over-8-mm-wide growth-inhibition zones of the colonies around disks saturated with ethanolic extracts from the fruits were observed for 11 bacteria: Enterobacter cloacae, Klebsiella pneumonia ssp. rhinoscleromatis, K. pneumonia ssp. ozaenae, K. aerogenes, Salmonella enterica, Escherichia coli, Morganella morganii, Enterococcus faecalis, E. faecium, Staphylococcus aureus, and Bacillus subtilis. Ethanol extract from the leaves inhibited growth of the colonies of 10 bacteria: E. cloacae, K. pneumonia ssp. rhinoscleromatis, K. pneumonia ssp. ozaenae, S. enterica, E. coli, Proteus vulgaris, E. faecalis, E. faecium, S. aureus, and B. subtilis. Ethanol extract from the stem inhibited growth of the colonies of only 6 bacteria: K. aerogenes, E. cloacae, P. vulgaris, E. faecium, S. aureus, and B. subtilis. Ethanol extract from the root inhibited growth of 10 bacteria: E. cloacae, K. pneumonia ssp. rhinoscleromatis, K. pneumonia ssp. ozaenae, K. aerogenes, S. enterica, E. coli, Pseudomonas aeruginosa, E. faecalis, E. faecium, and S. aureus. We analyzed the effects of extracts based on ethyl ether and dimethyl sulfoxide, finding no antiparasitic activity or expressed anthelmintic properties of various extracts from the fruits, leaves, stem, and roots of X. strumarium against larvae of the nematodes Strongyloides papillosus, Haemonchus contortus, and Muellerius capillaris.