Phytochemical Screening, Antimicrobial and Antioxidant Activity of Indigofera Linnaei

Abstract

The present study deals with the preliminary phytochemical study of Indigofera linnaei of family Fabaceae which is commonly known as Birdsville indigo. The Indigofera species has been cited in various literatures for its use in treating rheumatism, arthritis, infl ammation, tumor and liver diseases. The Pharmacognostical study revealed presence of important constituents like alkaloids, saponins, fl avonoids, terpenoids, steroids and tannins. The aerial part of the plant was macerated with methanol to get the methanolic extract. The Antimicrobial Activity of methanolic extract of Indigofera linnaei was performed using agar well diffusion method. The extract was tested against 4 different species of human pathogenic bacteria including two species of gram-negative (E.coli and Klebsiella pneumoniae) and two species of gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis). The zone of inhibition was observed and the response was compared with the standard drug, Streptomycin. The observations revealed that the extract showed considerable antibacterial activity against Bacillus subtilis. The extract exhibited moderate activity in case of Staphylococcus aureus. However, very mild activity was observed against gram negative organisms. The two extracts i.e. chloroform and methanol extract of Indigofera linnaei were studied for their antioxidant potential. The activityof two extracts were compared by in vitro methods namely DPPH and Hydrogen Peroxide Assay. Ascorbic acid was used as standard in DPPH method. The in vitro antioxidant study revealed that the extract showed good antioxidant activity as compared to the chloroform extract which showed less inhibitory effect in DPPH method while in hydrogen peroxide assay, chloroform extract showed good antioxidant activity compared to methanol extract.