Investigating the potential of under-utilised plants from the Asteraceae family as a source of natural antimicrobial and antioxidant extracts

• Published in: Food chemistry 2014-10, Vol.161, p.79-86
• Main Authors: Kenny, O., Smyth, T.J., Walsh, D., Kelleher, C.T., Hewage, C.M., Brunton, N.P.
• Format: Article
• Language: English
• Subjects: Anti-Infective Agents - therapeutic use; Antibacterial agents; Antibiotics. Antiinfectious agents. Antiparasitic agents; Antimicrobial; Antioxidants - therapeutic use; Arctium minus; Asteraceae; Asteraceae - microbiology; Bacillus cereus; Biological and medical sciences; Centaurea nigra; Centaurea scabiosa; Chromatography, Liquid - methods; Cirsium arvense; Cirsium palustre; Cirsium vulgare; Escherichia coli; Food toxicology; Medical sciences; Microbial Sensitivity Tests; Minimum inhibitory concentration antioxidant; Pharmacology. Drug treatments; Phenolics; Salmonella typhimurium; Scabiosa; Sonchus asper; Staphylococcus aureus; Tandem Mass Spectrometry - methods; Taraxacum officinale; Toxicology; UPLC–MS/MS
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2014.03.126

•5 ethanol extracts exhibited antimicrobial activity against Gram negative bacteria.•Ethanol extracts had higher antioxidant activities than water extracts overall.•Antioxidant activities of three Centaurea species are reported for the first time.•In general, ethanol extracts also possessed high phenolic content.•UPLC–MS/MS analysis identified phenolic compounds in all of the ethanol extracts. Antimicrobial properties of ethanol and water extracts from eight Asteraceae species were investigated against three Gram positive (Staphylococcus aureus, MRSA and Bacillus cereus) and two Gram negative (Escherichia coli and Salmonella typhimurium) bacterial strains. Ethanol extracts from Centaurea scabiosa, Arctium minus, Taraxacum officinale, Centaurea nigra and Cirsium palustre demonstrated antimicrobial activity against strains of S. aureus, MRSA and B. cereus (MIC=187.5–365μg/ml). Ethanol extracts also had higher antioxidant activities and phenolic content demonstrating a link between these compounds and the bioactivity of these extracts. Further investigation into the phenolic content of ethanol extracts using UPLC–MS/MS lead to the identification and quantification of numerous phenolic compounds in all species including; 18 from Cirsium arvense, 16 from Cirsium vulgare, 19 from C. palustre, 15 from C. nigra, 17 from C. scabiosa, 14 from Sonchus asper, 17 from A. minus and 11 from T. officinale.