Phytochemical screening and tyrosinase inhibitory activity of extracts from southern argentinean species

MANTÉ M; ORTEGA M. G; SANTI M.; COLLOCA, C, ; DEL GAUDIO M.; PLEITAVINO R

Otro; 4ª Reunión Internacional de Ciencias Farmacéuticas; 2016

Continuing the search for inhibitors compounds of tyrosinase, which would be important for the treatment of hyperpigmentary disorders, in this work we began the phytochemical studies of ethanolic extracts (EE) obtained from several native plants collected on the south of our country: Azorrella cfr trifurcata (Gaertn.) Pers. (EEAz), Empetrum rubrum Vahl ex Willf (EEEm), Plantago barbata subsp austro-andina Rahn (EEPl), Pernettya mucronata (L. f.) Gaudich. ex A. Spreng (EEPe) and Salicornia magellanica Phil (EESa). After carrying out the phytochemical screening, which allows determine the qualitatively presence of different metabolites, it was observed that all EE had flavonoids, being more marked in the EEAz and EEEm. Additionally it was observed that the extracts EEEm, EEAz and EEPl possessed tertiary alkaloids.Due to the presence of flavonoids in all extracts, and as these compounds have numerous precedents as tyrosinase inhibitors is that such activity was assayed. We use the methodology described by Peralta et al., 2014, measuring the appearance of dopachrome at 490 nm spectrophotometrically.Comparing with the reference inhibitor, kojic acid (IC50= 1.711 ± 0.004 µg/mL) the most active ethanolic extract was EEPl (IC50= 56.5 ± 0.3 µg/mL), followed by EEEm (IC50= 78.378 ± 0.001 µg/mL), EEAz (IC50= 99.614± 0.001 µg/mL), EESa (IC50 = 119.8 ± 0.6 µg/mL). EEPe proved to be inactive.We might attribute this moderate activity of the extracts to the presence of flavonoids, but deeper chemical studies would be needed to carry out the isolation and purification de los responsible for such activity.