Phytochemical Investigation and in vitro Antioxidant Activity of Different Leaf Extracts of Salix mucronata Thunb.

The present study was aimed to determine the phytochemical constituents of Salix mucronata Thunb. leaf extracts and their antioxidant activities. Dried leaf powder was extracted with MeOH, MeOH (85%), MeOH(70%) and distilled water. The different extracts were monitored for phytochemical screening. Total phenolic and flavonoid contents were measured by Folin-Ciocalteu and aluminum chloride assays. The antioxidant potential of tested extracts was evaluated using DPPH, ABTS and total antioxidant capacity (TAC) assays. The results showed that, MeOH (85%) extract exhibited high total phenolic and flavonoid contents (TPC=131.39±2.49 mgGAE /g ext. and TFC= 67.69±1.47 mg RE /g ext.). Also, MeOH (85%) extract showed high antioxidant activities (DPPH SC50= 98.76±0.46 (µg/ml), ABTS= 45.83±0.32 mm Trolox® eq. /100 gm extract and TAC= 199.18±2.19mg equivalent of ascorbic acid /g ext.). On other hand, EtOAc fraction derived from MeOH (85%) extract exhibited the highest antioxidant activity; DPPH SC50= 50.19±0.24 (µg/ml), ABTS= 76.22±1.61(mm Trolox® eq. /100 gm ext.) and TAC= 249.86±3.74 (mg equivalent of ascorbic acid /g ext.). This study demonstrated that, S. mucronata leaf is a good source of natural antioxidants. Also, there is a high correlation between the total phenolic content and the antioxidant activity.