In Vitro activity of extracts from Heterophyllaea Pustulata Hook F. (Rubiaceae) on Candida no albicans biofilms.

JULIANA MARIONI; JULIO ARCE MIRANDA; LAURA RAQUEL COMINI; SUSANA NUÑEZ MONTOYA; MARIA G. PARAJE

Córdoba

Jornada; XIII JORNADAS DE INVESTIGACIÓN CIENTIFICA DE LA FACULTAD DE CIENCIAS MEDICAS EN EL MARCO DEL 4º CENTENARIO DE LA UNC; 2012

FACULTAD DE CIENCIAS MÉDICAS-UNC

Introduction: Heterophyllaea pustulata Hook. f. (Rubiaceae), “cegadera”, is a native shrub of the NW Argentina and Bolivia, which extracts rich in anthraquinones (AQs) have shown in vitro antibacterial and antifungal effect against planktonic microorganisms. Since Candida no albicans is one of the main pathogens causing nosocomial infections in our country, especially because of its ability to form biofilms, the aim of this study was to evaluate the activity of different polarity extracts from this plant against biofilms formed by a Candida no albicans strain. Material and Methods: Four extracts were obtained (hexane, benzene, ethyl acetate and ethanol) from the aerial parts of this plant. Biofilm quantification was performed by O'Toole & Kolter method, using a clinical strain of C. no albicans. Sensitivity to the extracts was determined following the protocols of the Clinical and Laboratory Standards Institute, at three concentrations (0.2, 0.1 and 0.05 mg/ml) by triplicate. AQs identification in the extracts was achieved by Thin Layer Chromatography (TLC) by using standard compounds. Results: Although complete eradication of the biofilm was not produced by no extract tested, hexane and benzene extracts caused a significant decrease in its formation at the two highest concentrations tested, about 56 ± 2%. By TLC we determined that AQs are predominant in bioactive extracts, being rubiadina and soranjidiol the major derivatives. Conclusions: We established that the ability of the extracts obtained from H. pustulata to inhibit the biofilm growth of clinical C. no albicans is correlated with their high concentrations of AQs. These results encourage us to continue with the assessment of each purified AQ in order to establish which of these derivatives are responsible for the exhibited activity by the extracts, identifying those that achieve complete eradication of biofilms. Since microorganisms forming biofilms are resistant to antimicrobial agents, the obtaining of natural compounds active against these pathogens has significant value to health and economy that merit further investigations.