Phytochemical and antioxidant studies of methanol and chloroform extract from leaves of Azadirachta indica A. Juss. in Tropical region of Nepal

This research was carried out with the aim of phytochemical analysis and determining antioxidant activity present in methanol and chloroform leaf extracts of Azadirachta indica. Due to its potential in curing various ailments as well as wide spread application of antioxidant activity such as in the field of cosmetology, the plant was selected for the study. The total phenolics contained in the plant extracts were also studied which are responsible for the antioxidant activity. Antioxidant activity of the extracts were evaluated by diphenyl-β-picrylhydrazyl (DPPH) free radical scavenging method using ascorbic acid as standard in the concentration of 100, 50, 25 and 12.5 µg/ml. Phytochemical analysis were done with the established procedure and total phenolic content (TPC) was determined by using Folin-Ciocalteu colorimetric method. Phytochemical screening revealed the presence of similar constituents in both methanol and chloroform extracts such as alkaloids, glycosides, carbohydrate, phenol, flavonoid, steroids, protein, and amino acids. Total phenolic content in methanol and chloroform extracts were 207.39 ± 8.77 and 58.08 ± 4.41 mg gallic acid equivalent (GAE)/g, respectively. The inhibitory concentration (IC50) value for methanol and chloroform extracts of A. indica were calculated and found to be 80.28 and 439.60 µg/ml, respectively. The finding suggests that methanol extract of the plant has significantly more antioxidant activity than the chloroform extract as clarified by total phenolics contained in the plant. Key words: Phytochemical screening, antioxidant activity, total phenolic content, Azadirachta indica.