Larvicidal and antibiofilm potential of three mountain plants: Centaurea ensiformis, Origanum hypericifolium, Paeonia turcica

Background: Plants are known to produce a diverse group of natural metabolites with different biological activities. Centaurea ensiformis P.H. Davis, Origanum hypericifolium O. Schwartz & P.H. Davis, and Paeonia turcica Davis & Cullen are endemic plant species that grow on mountains in select regions in T & uuml;rkiye and have been used in traditional Turkish medicine for various ailments. Methods: As first, we evaluated the larvicidal and antibiofilm activities of ethanol, ethyl acetate, acetone, and water extracts obtained from these plants. Antioxidant activities of the extracts were also investigated. Results: All tested extracts were effective at concentrations > 25 ppm on Aedes aegypti larval mortality with the lethal concentration 50 (LC50) values ranging between 32.82-48.35 ppm and LC90 between 46.26-63.2 ppm. O. hypericifolium was the most effective plant, ethanol extracts presented LC50 values of 32.82 ppm. Extracts demonstrated varying degrees of antibiofilm activity depending on the dose and bacterial species. Origanum hypericifolium extracts notably inhibited biofilms of Staphylococcus aureus (up to 98% inhibition), while P. turcica showed moderate efficacy against the same bacterial species. Pseudomonas aeruginosa biofilms displayed high resistance to all extracts. Conclusion: The results indicated that these endemic Turkish plants possess promising larvicidal and antibiofilm potential, particularly Origanum hypericifolium. Extracts analyzed by liquid chromatography-tandem mass spectrometry contained caffeic acid, myricetin, cinnamic acid, quercetin, gallic acid, epicatechin, and ascorbic acid. Further research should explore their potential applications in mosquito control and biofilm-related infections.