Activités antioxydantes et anticoagulante des extraits polyphénoliques du Tilia Cordata Greenspire ((الزيزفون الحلبي

Abstract

Tilia cordata Greenspire, known locally as zaizafoune d'Alep, is a plant used to decorate urban areas on the one hand, and widely used in traditional medicine on the other hand. The aim of the present study was to evaluate the antioxidant and anticoagulant activities of polyphenolic extracts obtained by maceration of the delipidated powder of the aerial part of the lime tree (leaves and fruit) in distilled water alone and in hydroalcoholic mixtures (methanol and ethanol at 80% : 20% and at 50% : 50%). The total polyphenol and flavonoid contents in the various extracts measured by the folin-ciacolteu and aluminium trichloride colorimetric methods were > 53.33 ± 0.0024 μg GAE/g of dry extract and > 21.4 ± 0.00 μg eq/mg, respectively. It appears that the aerial part of Tilia is rich in polyphenols and flavonoids. In addition, the phytochemical screening results indicate the presence of anthocyanins, tannins, coumarins and reducing sugars. Evaluation of antioxidant power by DPPH and phenanthroline tests showed that polyphenolic extracts are considered powerful natural antioxidants with low IC50 and A0.5 respectively. With the exception of the aqueous extract, the hydroalcoholic extracts showed a very significant anticoagulant effect which is dose-dependent (extension of blood clotting time).