29 The leaves contain huge amount of vitamin C which is used in the treatment of oedema. 30 A decoction of the herb is used as a vermifuge and is useful in rheumatitis. It is also an antidote to alcoholic poison. 31 The present study was carried out with the aim to determine the chemical composition of essential oil isolated from T. decandra using GC–MS and to evaluate its antimicrobial activity and antioxidant activity against clinical bacterial and fungal selleck inhibitor pathogens. The leaves of T. decandra L. were collected from Salem district, Tamil Nadu, India during June 2008. The plant
was taxonomically identified and authenticated by the Botanical Survey of India, Coimbatore (Tamil Nadu) and voucher specimen No.BSI/SRC/5/23/10-11/Tech.975 was deposited in Plant Tissue Culture laboratory, SRM University for future reference. Aerial parts of T. decandra were washed with distilled water to remove dirt and soil, and were shade dried.
The dried plant material was powdered and passed through a 40-mesh sieve. The coarse powder (500 g) was extracted with petroleum ether (60–80°C), removed wax, and then extracted thrice with chloroform (CHCl3). The chloroform crude extract was desalted and dewaxed. It was dissolved in minimum quantity of acetone and absorbed over silica gel and transferred to a column (Column Height: 50 cm, Diameter: JQ1 9 cm) packed with silica gel (60–120 mesh) using petroleum ether and eluted with solvents of increasing polarity. The fractions eluted with petroleum ether: chloroform (3:1) gave a colourless liquid as an essential oil with a yield of 800 mg. To study the antimicrobial activity of various extracts of T. decandra, the strains of bacteria, yeast and fungi were collected from Institute of Microbial Technology, Chandigarh. The selected microorganisms included bacteria such as Staphylococcus aureus (MTCC 29213), Streptococcus faecalis (MTCC 0459), Enterococcus faecalis (MTCC 2729), E. coli (MTCC 443), P. aeruginosa (MTCC 1035), Salmonella typhi (MTCC heptaminol 98), Vibrio cholera (MTCC
3906), Proteus vulgaris (MTCC 1771), Bacillus subtilis (MTCC 121), Yersinia enterocolitica (MTCC 840) and fungi such as Candida albicans (MTCC 183) and Cryptococcus neoformans (MTCC 1346). The in vitro antimicrobial activity of the sample was studied by disc diffusion method. Sterile nutrient agar (Himedia) plates were inoculated with a loopful broth culture of each organism. Sterile discs (6 mm diameter) were impregnated with 20 μl (1 mg/disc) quantity of dimethyl sulfoxide solution of essential oil were air dried and placed on the seeded agar plates. The plates were incubated at 37 °C for 24 h. Libraries Chloramphenicol and nystatin (30 μg) were used as positive control. 32 After incubation, the DIZ was measured. Minimal inhibition concentration assay was performed in nutrient broth supplemented with resazurin according to the method.