Helichrysum arenarium as a source of flavonoids: Evaluation of antimicrobial activity and flavonoid content of extracts of Helichrysum flowers in vitro

Abstract

Background: Helichrysum (family Asteraceae, kind of H. armenium, subfamily of Asteroideae) is known in Armenian traditional medicine for its diuretic, antioxidant, choleretic and anti-inflammatory properties. Studies have shown that Helichrysum flowers have a high content of flavonoids. In this study, we investigated the impact of various extraction process parameters on the yield of flavonoids obtained from Helichrysum flowers in Armenia. Subsequently, a comprehensive antimicrobial assay was conducted on the ethanol and aqueous extracts derived from the dried flower heads of Helichrysum. Objective: The objective of this study is to explore the influence of extraction process parameters on the yield of flavonoids from H. arenarium flowers and to determine their antibacterial activity.Methods: Antibacterial activity was determined using the agar-well diffusion method against four bacterial species (E. coli, Salmonella enterica, Staphylococcus aureus and S. typhimirium). The assessment of the total flavonoid content in the ethanol extract of Helichrysum was conducted using the AlCl3 method, following the procedure outlined by Andreeva and Kalinkina. Results: The ethanolic and aqueous extracts demonstrated antibacterial activity against Staphylococcus aureus ATCC 6538 and Bacillus Subtilis 168. However, no significant activity was observed against Escherichia coli ATCC 8739 and Salmonella Typhimurium ATCC 14028. The research findings affirm that the extract derived from everlasting flowers exhibits antimicrobial properties, particularly targeting Gram-positive bacteria. Conclusion: The results of our tests indicate that the extract of Helichrysum belonging to Armenian flora, is rich in flavonoids and has significant antimicrobial activity and may find application in the food industry, as well as in organic agriculture.Keywords: Helichrysum, plant extracts, flavonoids, antimicrobial activity, spectrophotometry