Inula viscosa L. (Asteraceae): A study on its antimicrobial and antioxidant activities, chromatographic fingerprinting profile

Food products contaminated with pathogens and spoiled not only lead to a decrease in the quality and quantity of food products but also contribute to the spread of diseases, which are increasingly becoming a public health problem in both developed and developing countries. Due to the multiple resistance of these pathogens to antibiotics, the search for natural products with antimicrobial properties is becoming increasingly important. Inula viscosa has been used as a medicinal plant for a long time in many Mediterranean countries. The aim of this study was to investigate the antimicrobial effects of I. viscosa extracts against foodborne pathogens and their non-enzymatic antioxidant potential. Antimicrobial activity was measured using the disc diffusion method. Additionally, plant extracts were tested against 2,2-Diphenyl-1-picrylhydrazyl and 2,2'-azinobis (3-ethyl-benzothiazoline 6-sulfonate) radicals for antioxidant activity. Inula viscosa showed the highest antibacterial activity against Bacillus subtilis with the methanol extract (19 mm zone diameter), while the lowest activity was observed against Salmonella Typhimurium, with inhibition zone diameters of 7 mm. The highest antioxidant activity was recorded as 77.5% for the DPPH• method and 73.8% for the ABTS• method. In conclusion, this plant can be considered a natural antimicrobial and antioxidant agent against foodborne pathogens, and it is a promising candidate for large-scale experiments.