Antimicrobial activity of Helichrysum plicatum DC

Abstract

Dry flower heads of Helichrysum plicatum were characterized by HPLC-DAD and a detailed antimicrobial assay of its ethanol extract was performed. Identification of phenolic compounds indicated the presence of apigenin, naringenin and kaempferol as free aglycones, glycosides of apigenin, naringenin, quercetin and kaempferol as well as chlorogenic acid and chalcone derivate. Antimicrobial activity of the extract was evaluated against various bacteria and fungi as well as yeast Candida albicans using microdilution method. Grampositive bacteria were more sensitive to the tested extract (MIC values were to 0.02 mg/mL) than Gram-negative bacteria (the greatest MIC was 0.055 mg/mL). Regarding pathogenic fungi, our tests demonstrated that fungi were more sensitive to the tested extract than bacteria. The growth of the majority of the tested fungi was inhibited by concentration of 0.005 mg/mL. Moreover, the extract was significantly more active than commercial fungicide, fluconazole. The results of our tests indicate that the extract of H. plicatum has significant antimicrobial activity and may find application in the pharmaceutical and food industry and organic agriculture.

Keywords

• Helichrysum plicatum
• antimicrobial activity
• naringenin
• kaempferol
• apigenin