Aqueous Extract of Rubus ulmifolius Schott (Rosaceae) against Pathogenic Gram-Positive Oral Bacteria: an in Vitro Evaluation

Different Gram-positive bacteria, S. mutans, S. intermedius, S. anginosus, and E. faecalis, are often associated with different oral diseases, such as tooth decay, endodontic infections, and the occurrence of abscesses. A set of in vitro evaluations has been performed to assess the aqueous leaf extract of Rubus ulmifolius Schott as antimicrobial/antibiofilm activity against the above-mentioned pathogens by agar diffusion method and using a Standard antibiofilm model. The antioxidant activity was measured with the ABTS test. The extract's phenolic and flavonoid quantitative profiles were determined using the Folin-Ciocalteu reagent and a colorimetric method. The results suggested an interesting antimicrobial profile with a formulate range concentration amounting to (6.25-0.78) %. The antioxidant activity was with an EC50 = (0.0087 0.0009) mg/mL. The total phenolic content, expressed as the equivalent mass of gallic acid with respect to the dry mass of the extract, was (149 17) mg/g, and the total flavonoid concentration, calculated using quercetin as a reference compound, was (60 7) mg/g. Considering that until now, R. ulmifolius has not been sufficiently tested for its biological proprieties, these preliminary results encourage additional investigations for its use in the field of oral infections.