Posted by admin on Jun 1, 2012 in |
Phytochemical screening and antibacterial activity of aqueous and methanolic root extracts of Stachytarpheta indica Vahl. was assessed. Phytochemical analysis revealed the presence of flavonoids, terpenoides, tannins and reducing sugars. The antibacterial properties of both the aqueous and methanolic extracts were studied against clinically important bacteria viz., Escherichia coli, Bacillus cereus, Pseudomonas aeruginosa and Enterobacter aerogens by disc diffusion method. The aqueous extract showed significant activity against all the presently investigated species of bacteria which is comparable with standard antibiotic streptomycin. At the concentrations of 50-100µg /disc, aqueous extract showed significant zone of inhibition against E. coli, (14 mm), B. cereus (13 mm), P. aeruginosa, (17 mm), and E. aerogens (7 mm). Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) have been determined. The MIC values observed was 20, 30, 5 and 25µg/ml (for aqueous extract) and 40, 35, 20 and 30µg/ml (for methanolic extract) against E. coli, B. cereus, P. aeruginosa, and E. aerogens respectively. Further isolation of active compound responsible for the activity could be the potential...
Read More
Posted by admin on Jun 1, 2012 in |
Flavonoids have been reported to have many pharmacological activities, antimicrobial, antioxidant, cytotoxic, chemoprevention activities along with strong antiproliferative effects. The fruits of Garcinia lancaefolia Roxb., family Cluseaceae , a plant endemic to Assam has been used in locally to treat many diseases for which it was selected for investigationg its antimicrobial properties. No scientific validation has been made so far on its phytochemical content and the antibacterial activity for which the methanolic and water extract of plant parts were investigated by Agar Well Diffusion method. Furthermore, our phytochemical studies indicated that methanolic extract of Garcinia lancaefolia flowers and fruits contains flavonoids, tannins, reducing sugar, steroid terpene and cardiac glycosides. The total phenolic and flavonoids content studies were quantified for all the plant parts. Antibacterial activities of the crude extract were screened against wound infection causing 5 human pathogens. The most susceptible bacteria were S. aureus, followed by beta hemolytic Streptococcus pyogens, while the most resistant bacteria were E. coli, followed by Bacillus subtilis. From the screening experiment, the crude...
Read More
Posted by admin on Jun 1, 2012 in |
Pseudomonas aeruginosa, is one among the few drug resistant organisms causing Urinary Tract Infection. Most strains of Pseudomonas aeruginosa are significantly more resistant, even in the absence of R plasmids, to many antimicrobial agents, including β-lactams, tetracycline, chloramphenicol, and fluoroquinolones, than most other gram-negative rods. This broad-range resistance has so far been assumed to be mainly due to the low permeability of the P. aeruginosa outer membrane. Mex-proteins are the multidrug exporter proteins that are significant in drug ejection, which is the main reason for drug resistance. This limits the therapeutic options. Inhibition of multi drug resistant efflux pumps can restore the activities of antimicrobial agents that are substrates for these proteins. Hence efforts are now taken to screen few medicinal plants, which are both economic and less toxic. Among the several plants screened, we have chosen the acetone extract of Elephantopus scaber from which we purified a new terpenoid for our study. Its structure was generated using CHEMSKETCH software. The novel terpenoid was evaluated as potent efflux inhibitor. In...
Read More
Posted by admin on Jun 1, 2012 in |
A new series of flurobenzothiazole incorporated 1, 3, 4 – thiadiazole compounds have been synthesized. The structure of the synthesized compounds was confirmed by UV, IR, 1H NMR, Mass spectral analysis and evaluated for their antimicrobial activity against Proteus vulgaris NCTC 4635, Micrococcus leutus NL98, Aspergillus flavus ATCC 46646by disc diffusion method. The compounds SH8 and SH11 were also evaluated for the anti-inflammatory activity by carrageenan-induced paw oedema method. The synthesized compounds (SH6 to SH11) showed good antimicrobial activity. However the antimicrobial activity of the synthesized compounds against the tested organisms was found to be less than that of respective standard drugs used at tested dose level. The anti-inflammatory activity confirmed that the test compound SH11 showed superior activity in the inhibition of oedema than SH8. However, both the test compounds were found to be less active than the standard drug...
Read More
Posted by admin on May 1, 2012 in |
Due to the outbreak of infectious diseases caused by different pathogenic bacteria and the development of antibiotic resistance, the pharmaceutical companies and the researchers are now searching for new unconventional antibacterial agents. Nanotechnology represents a modern and innovative approach to develop new formulations based on metallic nanoparticles with antimicrobial properties. The potential bioactivity of chemically fabricated silver nanoparticles has been extensively studied. However, the antibacterial activity of silver nanoparticles individually or in combination with different antibiotics has not been demonstrated. In the present investigations, the effect of silver nanoparticles on the antibacterial activity of different antibiotics was evaluated against selected human bacterial pathogens such as Staphylococcus aureus, Streptococcus epidermis, Escherichia coli, Pseudomonas aeruginosa, and Bacillus cereus by disc diffusion method.In the presence of sub – inhibitory concentration of silver nanoparticles (100µL/disc), the antibacterial activities of all antibiotics are increased from 1 mm to 10 mm. The maximum fold increase was noticed for vancomycin against Pseudomonas aeruginosa (66.67%), Escherichia coli (62.50%), and Staphylococcus aureus (46%) followed by rifampicin against Bacillus...
Read More
