Phytochemical Screening, Antioxidant and Antimicrobial Activities of Neem Seed (Azadirachta indica) Extracts

Abstract

In this study, the phytochemical, antimicrobial and antioxidant activity of neem seed oils (Azadirachta indica) was analyzed. The extract was extracted by solvent extraction using n-hexane, ethyl acetate, methanol and aqueous solvents. The percentage yields of the extraction were 42.50%, 40.70%, 38.30% and 28.50% for the n-hexane, ethyl acetate, methanol and aqueous solvents respectively. The phytochemical screening of the samples revealed the presence of alkaloids, flavonoids, steroids, anthraquinones, cardiac glycosides and terpenoids in neem seed extract. The minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and minimum fungicidal concentration of the neem seed extract was determined on Escherichia coli, Staphylococcus aureus, Aspergillus niger and Candida albicans. The MIC for neem seed extract in methanolic extract on E. coli and S. aureus was the least at 6.25% concentration while the MIC on the fungi (A. niger) was at 50% concentration having a zone of inhibition of 7.67± 0.71mm. There was no growth inhibition in C. albicans. The neem seed extract was shown to possess an antioxidant activity using DPPH radical. There was a significant increase in the scavenging activity of the neem seed extract as the concentration increased from 6.25% to 100%. The blended quantity of the neem seed extract showed the highest scavenging activity of 54.19 ± 0.03%. The study shows the extracts of neem seed possess good bioactive agents, antioxidant and antibacterial activity, and therefore they could be effectively used as a natural source of antioxidants and to be detected against gram-positive bacteria.