Chicory ( <i>Cichorium intybus</i> ) Leaves Extract: Phenolic Composition, Antibacterial Activity, and Antioxidant Capacity Assessment

<i>Cichorium intybus</i>, a plant with a long history of medicinal use, was extracted using three solvents: hexane, ethanol, and ethyl acetate. The resulting extracts were subjected to chromatographic analysis, yielding five distinct fractions. Fractions I and II were obtained from the ethyl acetate extract, whereas Fractions III, IV, and V were derived from the ethanol extract. This study evaluated the antibacterial activity of these fractions against five virulent Gram-negative bacteria associated with periodontitis: <i>Neisseria perflava</i>, <i>Eikenella corrodens</i>, <i>Neisseria pharyngis</i>, <i>Morococcus cerebrosus</i>, and <i>Neisseria mucosa</i>. The results demonstrated that Fraction I exhibited significant antibacterial activity, with an inhibition zone of 26 mm against <i>N. pharyngis</i> and <i>N. mucosa</i> at a concentration of 200 μg/mL. Fraction II showed notable inhibition against <i>E. corrodens</i> and <i>N. pharyngis</i>. Fraction III achieved a maximum inhibition zone of 35 mm against <i>N. pharyngis</i> at 100 μg/mL and <i>M. cerebrosus</i> at 200 μg/mL. Similarly, Fraction IV exhibited potent antibacterial activity, with a peak inhibition zone of 35 mm at 100 μg/mL. Fraction V also produced an inhibition zone of 35 mm against <i>N. pharyngis</i> at 100 μg/mL. Compared with standard antibiotics, such as ampicillin and cephalosporin, the fractions demonstrated comparable efficacy. In addition to antibacterial activity, the study investigated the antioxidant and free radical scavenging capacities of the isolated fractions at various concentrations (ppm), using vitamin C as a reference. Fractions I and II showed the highest antioxidant activity at 30 ppm, with values reaching 22.36. Fraction V exhibited the most potent activity, with antioxidant values of 35.65 at 30 ppm, 56.22 at 60 ppm, 76.44 at 120 ppm, and continued enhancement at 250 ppm. These findings highlight the promising bioactive potential of <i>C. intybus</i> extracts and provide a solid foundation for further investigation into their therapeutic applications in managing bacterial infections and oxidative stress. The detailed results emphasize the importance of continued research into the mechanisms and complexities of these bioactive compounds.