STUDIES ON ANTIBACTERIAL ACTIVITY, ANTIOXIDANT ACTIVITY AND GC-MS ANALYSIS OF NIGELLA SATIVA SEEDS

The Nigella sativa seeds were collected from Cuddalore and powdered thoroughly by using mortor and pestle. The Nigella sativa seeds were individually extracted with different solvents such as ethanol, methanol, acetone and water. The antibacterial activity of seed extracts were tested against the 6 ATCC pathogens such as Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Clostridium sporogenes, Bacillus spizizenii and Pseudomonas aeruginosa using Muller Hinton agar. The ethanol extract of Nigella sativa seed showed maximum activity against Klebsiella pneumoniae (12 mm) and Bacillus spizizenii (12 mm). The methanol extract of Nigella sativa seed exhibited minimum activity against Clostridium sporogenes (8mm), Escherichia coli (8mm), Pseudomonas aeruginosa (8mm) and highest activity against Klebsiella pneumoniae (20mm). The acetone extract of Nigella sativa seed showed highest activity against Escherichia coli (20mm). The aqueous extract of Nigella sativa seed showed maximum inhibitory activity against Klebsiella pneumoniae (23mm). Among the 4 solvent extracts, water extracts of Nigella sativa seed showed maximum inhibition. The GC-MS analysis of the Nigella sativa seed extract was carried out and it showed the following major phytochemical constituents such as Piperidine, 1-(2-phenylethyl)- , p-cymene, cis-4-methoxy thujane, Thymoquinone, phenol, 2-methyl-5-(1-methylethyl)-, Tricyclo[5.4.0.0(2, 8) ]undec-9-ene, 2,6,6,9-tetramethyl-(1R, 2S, 7R, 8R)- , Longifolene, p-cymene-2, 5-diol, Tetradecanoic acid, Hexadecanoic acid, methyl ester, n-Hexadecanoic acid,9,12-octadecadienoic acid(Z-Z)-, 11-14-Eicoradienoic acid, Glycerol 1-palmitate, 9,12-Octadecadienoic acid (Z, Z)-,2-hydroxy 1-(hydroxymet), Ethanol, 2-(9,12-Octadecadienyloxy)-,(Z-Z) – , beta. -Sitosterol, 2-Dodecen-1-yl(-) succinic anhydride. The methanol seed extract of Nigella sativa showed the % of antioxidant activity using DPPH assay was 19.88% where the positive control ascorbic acid showed 98.68%.