Photodynamic inactivation of Gram-positive bacteria employing natural resources.
The aim of this paper was to investigate a collection of plant extracts from Argentina as a source of new natural photosensitizers (PS) to be used in Photodynamic Inactivation (PDI) of bacteria. A collection of plants were screened for phototoxicity upon the Gram-positive species Staphylococcus epidermidis. Three extracts turned out to be photoactive: Solanum verbascifolium flower, Tecoma stans flower and Cissus verticillata root. Upon exposure to a light dose of 55J/cm(2), they induced 4, 2 and 3logs decrease in bacterial survival, respectively. Photochemical characterisation of S. verbascifolium extract was carried out. PDI reaction was dependent mainly on singlet oxygen and to a lesser extent, on hydroxyl radicals, through type II and I reactions. Photodegradation experiments revealed that the active principle of the extract was not particularly photolabile. It is noticeable that S. verbascifolium -PDI was more efficient under sunlight as compared to artificial light (total eradication vs. 4 logs decrease upon 120min of sunlight). The balance between oxidant and antioxidant compounds is likely to be masking or unmasking potential PS of plant extracts, but employing the crude extract, the level of photoactivity of S. verbascifolium is similar to some artificial PS upon exposure to sunlight, demonstrating that natural resources can be employed in PDI of bacteria.
Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP), CONICET and Hospital de Clínicas José de San Martín, University of Buenos Aires, Córdoba 2351 1er subsuelo, Ciudad de Buenos Aires CP1120AAF, Argentina.
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Mamone
Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP), CONICET and Hospital de Clínicas José de San Martín, University of Buenos Aires, Córdoba 2351 1er subsuelo, Ciudad de Buenos Aires CP1120AAF, Argentina.
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Di Venosa
Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP), CONICET and Hospital de Clínicas José de San Martín, University of Buenos Aires, Córdoba 2351 1er subsuelo, Ciudad de Buenos Aires CP1120AAF, Argentina.
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Gándara
Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP), CONICET and Hospital de Clínicas José de San Martín, University of Buenos Aires, Córdoba 2351 1er subsuelo, Ciudad de Buenos Aires CP1120AAF, Argentina.
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Sáenz
Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP), CONICET and Hospital de Clínicas José de San Martín, University of Buenos Aires, Córdoba 2351 1er subsuelo, Ciudad de Buenos Aires CP1120AAF, Argentina.
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Vallecorsa
Hochschule Aalen, Institut für Angewandte Forschung, Beethovenstr. 1, 73430 Aalen, Germany.
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Schickinger
Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP), CONICET and Hospital de Clínicas José de San Martín, University of Buenos Aires, Córdoba 2351 1er subsuelo, Ciudad de Buenos Aires CP1120AAF, Argentina.
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Rossetti
Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP), CONICET and Hospital de Clínicas José de San Martín, University of Buenos Aires, Córdoba 2351 1er subsuelo, Ciudad de Buenos Aires CP1120AAF, Argentina.
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Batlle
Instituto de Microbiología y Parasitología Médica (IMPaM), CONICET-UBA, Argentina.
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Buzzola
Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP), CONICET and Hospital de Clínicas José de San Martín, University of Buenos Aires, Córdoba 2351 1er subsuelo, Ciudad de Buenos Aires CP1120AAF, Argentina. Electronic address: adriana@qb.fcen.uba.ar.
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Casas
D029402:Bignoniaceae / Q000737:chemistry / Q000378:metabolism; D032422:Cissus / Q000737:chemistry / Q000378:metabolism; D052978:Disk Diffusion Antimicrobial Tests; D035264:Flowers / Q000737:chemistry / Q000378:metabolism; D006090:Gram-Negative Bacteria / Q000187:drug effects / Q000528:radiation effects; D006094:Gram-Positive Bacteria / Q000187:drug effects* / Q000528:radiation effects; D038761:Photobleaching; D017319:Photosensitizing Agents / Q000737:chemistry / Q000494:pharmacology*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D018517:Plant Roots / Q000737:chemistry / Q000378:metabolism; D026082:Singlet Oxygen / Q000378:metabolism; D032322:Solanum / Q000737:chemistry / Q000378:metabolism
D017319:Photosensitizing Agents; D010936:Plant Extracts; D026082:Singlet Oxygen
Bacteria; Natural products; Photodynamic therapy; Photoinactivation; Plants; Sunlight