IN VITRO ANTIOXIDANT ACTIVITY AND PHYTOCHEMICAL PROPERTIES OF METHANOL, ETHANOL AND HEXANE EXTRACTS OF AZADIRACHTA INDICA LEAVES.

ABSTRACT

Azadirachta indica, commonly known as Neem, has attracted worldwide prominence in recent years as a cynosure of modern medicine owing to its wide range of medicinal properties. This study was carried out to investigate the phytochemical properties and antioxidant activity of the multi-solvent (methanol, ethanol and hexane) extracts of the leaves of Azadirachta indica of Meliaceae family. The extracts were investigated for phytochemical constituents such as tannins, saponins, alkaloids, total flavonoids, total phenols and proanthocyanidin, while the in vitro antioxidant activity was determined using DPPH scavenging assay, FRAP assay, metal ion chelating assay and reducing power assays. Total phenol content of extracts were also determined by Folin-Ciocalteu method. Experimental results obtained for phytochemical studies revealed that flavonoids content is highest in the methanol extract (79.10±1.15 mg QE/g extract), while the ethanol extract had the lowest content. Also, the methanol extract of A. indica leaves has the highest fraction of crude extract, highest phenol content (342±10.2 mg GAE/g extract), highest tannin content (97.83±3.49 mg TAE/g extract), highest proanthocyanidin content (13.17±2.85 mg AAE/g extract). Qualitative studies show the presence of the various phytochemicals in varying amounts; however, cardiac glycosides were absent in the hexane and ethanol extracts, alkaloids were absent in the ethanol extract, while saponins were absent in the hexane extract. Similarly, IC50 values of the ethanolic extract of A. indica leaves (IC50 values of 81.62µg/ml and 83.29µg/ml) were lower than other extracts for DPPH scavenging assay and metal ion chelating respectively. The various extracts of A. indica leaves may be exploited for clinical medicine as potent factors because of their high antioxidant activity.