CONICET | Buscador de Institutos y Recursos Humanos

BC-P20 CHARACTERIZATION OF L-LEUCINE TRANSPORT IN Saccharomyces cerevisiae GROWN IN MEDIUM SUPPLEMENTED WITH Moringa oleifera PichettoOlanda I, Congost C, Grondona G, Mónaco C, Chapela SP, Burgos HI, Alonso M, Stella CA INBIOMED UBA-CONICET. Facultad de Medicina. UBA.E-mail: cstella@fmed.uba.ar Yeast model system is suitable to study the effect of different substances on the metabolism of eukaryotic cells. The system avoids effects present in cells of higher eukaryotes due to organ or tissues interaction. Tea extracts of M.oleifera (―moringa‖) have been considered beneficial to be incorporated into the diet of diabetic patients or with antioxidant properties. However, these beneficial effects have not been elucidated from the point of view of cellular biochemistry. The objective of the present work is to characterize the transport of the amino acid L-leucine in a culture medium supplemented with M.oleifera. Extracts of C.sinensis (―green‖) and C.angustifolia (―sen‖) were used for comparison. Results obtained show that the transport of the amino acid is increased in all media with respect to the control medium with yeast extract/peptone (YPD). The general amino acid system (GAP1) would be responsible for the observed phenotype. In the case of the sen extract it is found that it produces a phenotype highly sensitive to the presence of H2O2 in the solid culture that can be reversed by the addition of antioxidant N-acetyl cysteine. Both,sen and green tea increase the degradation of H2O2 , which can be reasoned as to a greater activity of the catalase enzyme. Results can be interpreted considering that the extracts provide a poor source of nitrogen analogous to the amino acid L-proline. This amino acid requires greater activity of mitochondrial oxidative metabolism and concomitantly there is an increase in nonspecific amino acids transport systems activity.