Romanian Society of Pharmaceutical Sciences

« Back to Farmacia Journal 2/2017

THE SELECTION OF TECHNOLOGICAL PARAMETERS IN ORDER TO OBTAIN AN EXTRACT WITH IMPORTANT ANTIOXIDANT ACTIVITY FROM STINGING NETTLE LEAVES

IOANA NENCU1*, LIDIA MARIA POPESCU1, VIORICA ISTUDOR1, TEODORA COSTEA1, LIGIA ELENA DUŢU1, CERASELA ELENA GÎRD1

1.“Carol Davila” University of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacognosy Phytochemistry Phytotherapy, 6 Traian Vuia Street, 020956, Bucharest, Romania

Download Full Article PDF

The aim of this study was to examine the effects of the plant stage development and the extraction parameters (solvent polarity and extraction procedure) on stinging nettle polyphenolic content and antioxidant activity, in order to select the optimal technological parameters for the obtaining of an extract with high antioxidant activity from stinging nettle leaves. The total polyphenolic (T.P.) content of the extracts was determined using Folin Ciocalteu’s method. The antioxidant potential was assessed using the DPPH (1,1-diphenyl-2-picrylhydrazyl) and ABTS [2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid] methods. The extract with the highest antioxidant effect was obtained by reflux extraction of leaves with 50% ethanol (water:ethanol = 50:50, v/v) (extract D 37.0 mg% tannic acid, IC500 for DPPH and ABTS are 50.39 µg/mL, respectively 91 µg/mL). The correlation factors of ABTS-T.P. and DPPH-T.P. were high for the immature leaves (0.94 and 0.96, respectively) and modest for mature ones (0.76 and 0.33). These results imply that T.P. are major contributors to the antioxidant activity of young nettle leaves. In conclusion, our research indicated that the optimal technological parameters for obtaining extracts with high antioxidant activity from stinging nettle leaves are: refluxing immature raw material using 50% ethanolic solution.