Antibacterial activity of natural anthraquinones.

COMINI L.R.; HEUMANN V.; PAÉZ P.L.; ALBESA I.; NÚÑEZ MONTOYA S.C.; CABRERA J.L.

Córdoba, Argentina

Otro; PRIMERA REUNIÓN INTERNACIONAL DE CIENCIAS FARMACÉUTICAS-RICiFa; 2010

Fac. Cs. Qcas. UNC

Substances with photosensitizing characteristics have become particularly important in the field of pharmacology due to their potential applications (1). In relation to this, research oriented towards photodynamic antimicrobial chemotherapy is in progress with promising results. This therapeutic treatment consists in the application of ultraviolet or visible radiation (UV-Vis) on infected tissue, which is previously associated to the photosensitizer (PS), which is activated by light in order to produce reactive oxygen species (superoxide anion radical and/or singlet molecular oxygen). These species act on microorganisms, generating microbial inactivation (2). Previously, we have demonstrated that three majority anthraquinones (AQs): rubiadin, soranjidiol and rubiadin 1-methyl ether, isolated from stems and leaves of Heterophyllaea pustulata, showed photosensitizing properties by generation of superoxide anion radical and/or singlet molecular oxygen under irradiation conditions (3). On the other hand, in previous microbiological studies we have established that two of the tested AQs (rubiadin and soranjidiol), have in vitro photodynamic antimicrobial activity against Gram (+) bacteria (Staphylococcus aureus ATCC 25923) (4). In the present work, the objective was to evaluate the antibacterial activity of these AQs against another microorganism that belong to Gram (+) genus: Staphylococcus epidermidis ATCC 12228, by using the Minimum Inhibitory Concentration (MIC) determination that is a routine susceptibility tests, which allows to estimate the bacteriostatic action of a compound.