Phytochemical screening, total phenolic content and in vitro antioxidant studies of leaf, bark and flower extracts of Schefflera spp. (Araliaceae)

In the present study, the phytochemical constituents and antioxidant activity of various extracts from leaves, bark and flower of S. venulosa and S. wallichiana was investigated by different in-vitro methods. Phytochemical investigation revealed the presence of saponins, tannins, flavonoids, alkaloids, cardiac glycosides and reducing sugars in both plant species. Estimation of total phenolic content and free radical assays such as 1,1-diphenyl-2-picryl hydrazyl (DPPH), Ferric reducing antioxidant power (FRAP) and Reducing power assay were performed. The phenolic content varied from 0.36±0.05 to 93.41±0.22 mg GAE/g extract in both plant species. Aqueous flower extracts of S. venulosa (IC50 = 13.16 µg/ml) and aqueous leaf extract of S. wallichiana (14.13±0.01µg/ml) showed potent antioxidant activity. The maximum reducing ability in the FRAP assay was observed in aqueous flower extracts of S. venulosa (195.77±0.14 µM Fe (II) /g) and aqueous leaf extract of S. wallichiana (193.43±0.14 µM Fe (II) /g). OD at 700 nm for reducing power assay also showed similar results for the aqueous flower extracts of S. venulosa (2.05±0.25 OD) and aqueous leaf extract of S. wallichiana (2.00±0.18). The results provide evidence that the studied plants might indeed be potential sources of natural antioxidants.