EVALUATION OF PHENOLIC COMPOUNDS, FLAVONOIDS AND ANTIOXIDANT PROPERTIES OF ARGANIA SPINOSA (L.) SKEELS LEAF EXTRACTS

摘要

Argania spinosa (L.) Skeels (Sapotaceae family) is an endemic species from Algeria (Tindouf region) and south-west of Morocco and is a Saharan affinity medicinal plant. In this study, the extraction of phenolic compounds from the leaves of Argania spinosa (L.) Skeels is carried out using solvents of different polarity. The yields of extraction from the leaves were 27.7%, 0.7%, 2.1% and 18.1% for the crude, chloroform, ethyl acetate and aqueous extracts respectively. The levels of total polyphenols, determined by Folin–Ciocalteu’s reagent, in plant extracts varied from 447 ± 0.028 to 106.33 ± 0.062 mg/g dry weight, expressed as gallic acid equivalents (GAE) for ethyl acetate and chloroform extracts respectively. Total flavonoid contents were determined using aluminum chloride and the crude extract contained the highest content with 185.93 ± 0.009 mg quercetin Eq/ g of dry extract. Different antioxidant tests were employed to evaluate the antioxidant activities of these extracts. The EAE showed the highest antioxidant activity using β-carotene/ linoleic acid, DPPH, phenanthroline-Fe (II) oxidation and reducing power assays with 90%, 0.014 ± 0.0001 mg/ml, 0.13 ± 0.0008 mg/ml and 1.859 ± 0.037 respectively. The results were compared with natural and synthetic antioxidants.