Evaluation of the antimicrobial and antioxidant activities of Onobrychis oxyodonta Boiss. extracts obtained with different solvents

This study investigated the antimicrobial and antioxidant activity of ethanol and methanol extracts of stems, leaves, flowers, and seeds of Onobrychis oxyodonta collected from Diyarbakır. Standard pathogens, namely Gram-negative (Escherichia coli ATCC 25922) and Gram-positive (Streptococcus pyogenes ATCC 19615) bacteria and yeast (Candida albicans ATCC 10231), were used as test microorganisms for the antimicrobial activity study. While sufficient activity was not observed against Escherichia coli, anti-Streptococcal activity was observed against S. pyogenes in both solvent extracts. The highest activities were observed in the ethanol extract for stems, flowers, seeds, and leaves, respectively, while in the methanol extract, the highest activities were observed for stems, flowers, leaves, and seeds, respectively. In antioxidant activity studies, the highest TPC (total phenolic content) ratio was found in the leaf ethanol extract with 88.75 GA equivalent (mgGAE/g extract); in FRAP (highest iron reducing power activity) results, the highest activity was found in the methanol extract with 198.05 TE equivalent (mgTE/g extract), both solvents showing the highest activity. The highest DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity results were observed significantly in the leaf methanol extract. The findings obtained from the experiments revealed that O. oxyodonta possesses antimicrobial and antioxidant properties. it is determined that O. oxyodonta extracts have potential as natural sources of bioactive substances for future pharmaceutical or functional food applications.