In Vitro Evaluation of Antimicrobial Photodynamic Therapy Associated with Hydroalcoholic Extracts of Schinopsis brasiliensis Engl.: New Therapeutic Perspectives

• Published in: Photomedicine and laser surgery Vol. 33; no. 5; p. 240
• Main Authors: Formiga Filho, Amaro L N, Carneiro, Vanda S M, Souza, Emmanuel A, Santos, Ravely L, Catão, Maria Helena C V, Medeiros, Ana Cláudia D
• Format: Journal Article
• Language: English
• Published: United States 01-05-2015
• Subjects: Anacardiaceae; Anti-Infective Agents, Local - pharmacology; Escherichia coli - drug effects; Escherichia coli - radiation effects; Photochemotherapy; Plant Extracts - pharmacology; Pseudomonas aeruginosa - drug effects; Pseudomonas aeruginosa - radiation effects; Rosaniline Dyes - pharmacology; Staphylococcus aureus - drug effects; Staphylococcus aureus - radiation effects
• ISSN: 1557-8550
• DOI: 10.1089/pho.2014.3796

The aim of this study was to evaluate the photodynamic potential of extracts of Schinopsis brasiliensis Engl. on bacteria involved in several human infections.
Photodynamic therapy (PDT) involves the interaction of light with an appropriate and photosensitizer wavelength, and the prospect of existing photosensitive compounds in herbal extracts enhanced by the application of laser diode has been promising.
The antibacterial activity against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Enterococcus faecalis was obtained by the disk diffusion method on agar. The laser diode InGaAIP was used with 660 nm wavelength, 100 mW, and 4 J/cm(2), and the application was performed in a timely manner for 34 sec on each disk tested. The groups tested were: Laser and bark extract (B+L+); bark extract only (B+L-); Laser and leaf extract (F+L+); leaf extract only (F+L-); Laser and malachite green (M+L+); malachite green only (M+L-); and laser only (L+).
There were significant differences between the B+L- and B+L+ groups (p=0.029) and between the L+F- and L+F+ groups (p=0.029) at various concentrations of the nebulized extracts of bark and leaf. Among the tested pathogens, S. aureus showed the highest zone of inhibition, 24.55±0.36 mm in group B+L+, 500 mg.mL(-1).
PDT with malachite green was effective, and groups B+L+ and F+L+ showed excellent activity on the bacteria tested, suggesting the presence of photosensitizers in extracts of S. brasiliensis Engl.