Photoactivable molecules generate tissular damage by ROS on immature stages of dipterans.

MASSALDI, ANA; PUJOL LEREIS, LUCIANA; FILIBERTI, ADRIÁN; RADRIZZANI, MARTÍN; RABOSSI, ALEJANDRO; QUESADA ALLUÉ, LUIS ALBERTO

Rosario, Santa Fé

Congreso; 42 ava Reunón SAIB; 2006

Soc. Arg. Invest. Bioquimicas y Biología Molecular (SAIB)

Photoactivable molecules generate tissular damage by ROS on immature stages of dipterans. Massaldi, A; L. Pujol-Lereis; A. Filiberti1; M. Radrizzani; A. Rabossi and L.A. Quesada- Allué. IIBBA-CONICET, FCEyN-UBA y Fundación Instituto Leloir, Patricias Argentinas 435 (1404), Buenos Aires. (1) CIQUIBIC-CONICET-UNC Photoactivable substances react upon absorption of visible radiation with the subsequent formation of reactive oxygen species. We previously demonstrated the photochemical toxicity of Phloxine B (PhB) (a red xanthene eosin) on immature stages of the Medfly, Ceratitis capitata. This dye represents an interesting option to traditional insecticides. Hematoporphyrin (HP) and the lactone Santonin were also possible alternatives. We found that Hematoporphyrin was aproximately 3 times more toxic than PhB (LC50: 0.143 mM) whereas Santonin do not showed significant effects. To understand the toxic effects of photoactivable substances at the tissular level we have examined the level of macromolecular damage (lipid peroxidation and DNA damage) in different tissues of Ceratitis Capitata.  Lipid peroxidation was found in larvae fed with three photoactivable substances under light and dark conditions.  We have further determined the activation of celular mechanisms such as an increase of the PKB/ AKT pathway by inhibition of PTEN and an increase in nuclear localization of a Rel-like transcription factor in intestine nuclei of larvae fed with PhB as evidenced by EMSA.