In vitro antimicrobial activity of crude ethanol extracts and fractions of Terminalia catappa and Vitex doniana.

BACKGROUND: The spread of microorganisms resistant to some antimicrobial agents necessitates the need to search for novel and effective antimicrobial agents. In this study, the antimicrobial activity of Terminalid catappa Linn. (Combretaceae) and Vitex doniana Sweet. (Verbenaceae), two Nigerian medicinal plants used in folk medicines for the management of various ailments related to microbial infections were evaluated. OBJECTIVES: To evaluate the antimicrobial activity of the crude ethanol extracts and fractions of the leaves and stem bark of T. catappa and V. doniana. METHODOLOGY: Four crude ethanol extracts and 16 (n-hexane, ethylacetate, n-butanol and aqueous) fractions of leaves and stem bark of T. catappa and V doniana were evaluated for in vitro antimicrobial activity against fifteen (15) strains of bacteria and fungi. The antimicrobial activity was determined in a 96-well plate using a resazurin based broth microdilution method. Two standard antimicrobial drugs ampicillin and nystatin were included as positive control. RESULTS: The butanoL fraction of stem bark of T. catappa and ethanol crude extract of leaf of V don iana displayed the highest antibacterial activity with similar minimum inhibitory concentration (MIC) value of 93.75 microg/mL against S. aureus and B. subtilis. Furthermore, the ethyl acetate fraction of stem bark of T. catappa showed the highest antifungal activity with MIC of 187.5 microg/mL against A. sydowi. Amp icillin had MIC of 15.6 and 31.3 microg/mL against S. aureus and B. subtili, respectively while nystatin produced MIC of 3.9 microg/mL against A. sydowi. CONCLUSION: Termninalia catappa and Vitex doniana may serve as useful sources of plant derived antimicrobial agents.

Evaluation of Antioxidant Activity of Picrorhiza kurroa (Leaves) Extracts.

Picrorhiza kurroa is a well-known herb in Ayurvedic medicine. Although it shows antioxidant, antiinflammatory and immunomodulatory activities, it is most valued for its hepatoprotective effect. The rhizomes are widely used against indigestion problems since ancient times due to improper digestive secretions. Aim of this study was to explore antioxidant study of P. kurroa leaves for a new source of naturally occurring antioxidants. Two pure compounds, luteolin-5-O-glucopyranoside (1) and picein (2) were isolated from butanol extract through column chromatography. Different extracts of P. kurroa leaves (ethanol, ethyl acetate, butanol) were quantified for isolated compound (2) by high-performance liquid chromatography. All the extracts and isolated compounds were evaluated for its antioxidant activity using two assays, 2,2-diphenyl-1-picrylhydrazyl radical and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) assay. The linear detection range was 1.56-200 µg/ml for picein. The limit of detection and limit of quantification for picein were 2.34 and 7.81 µg/ml, respectively. Butanol and ethyl acetate extract showed greater antioxidant activity as compare to ethanol extract. Compound 1 and ascorbic acid showed nearly similar antioxidant activity where as 2 showed no activity at standard concentration. The IC50 values for 2,2-diphenyl-1-picrylhydrazyl radical and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) assay for ascorbic acid, compound 1, ethanol extract and its different fractions (ethyl acetate and butanol) were found to be 0.81, 1.04, 67.48, 39.58, 37.12 and 2.59, 4.02, 48.36, 33.24, 29.48 µg, respectively.

Inspiratory and expiratory aerosol deposition in the upper airway.

Aerosol deposition efficiency (DE) in the extrathoracic airways during mouth breathing is currently documented only for the inspiratory phase of respiration, and there is a need for quantification of expiratory DE. Our aim was to study both inspiratory and expiratory DE in a realistic upper airway geometry. This was done experimentally on a physical upper airway cast by scintigraphy, and numerically by computational fluid dynamic simulations using a Reynolds Averaged Navier?Stokes (RANS) method with a k-? SST turbulence model coupled with a stochastic Lagrangian approach. Experiments and simulations were carried out for particle sizes (3 and 6 µm) and flow rates (30 and 60 L/min) spanning the ranges of Stokes (Stk) and Reynolds (Re) number pertinent to therapeutic and environmental aerosols. We showed that inspiratory total deposition data obtained by scintigraphy fell onto a previously published deposition curve representative of a range of upper airway geometries. We also found that expiratory and inspiratory DE curves were almost identical. Finally, DE in different compartments of the upper airway model showed a very different distribution pattern of aerosol deposition during inspiration and expiration, with preferential deposition in oral and pharyngeal compartments, respectively. These compartmental deposition patterns were very consistent and only slightly dependent on particle size or flow rate. Total deposition for inspiration and expiration was reasonably well-mimicked by the RANS simulation method we employed, and more convincingly so in the upper range of the Stk and Re number. However, compartmental deposition patterns showed discrepancies between experiments and RANS simulations, particularly during expiration.

Clinical aspects of centipede bite in the Andamans.

Clinical aspects of centipede bite as seen in the Andamans are reported. Centipede bite produces excruciating local pain and burning. Local bleeding is common but transient. Occasionally local infection or necrosis develops. Constitutional upset occurs in a small minority. Centipede bites are never fatal and pain-relief is the cornerstone of treatment.

A New Limonoid, Amoorinin, from the Stem Bark of Amoora rohituka.

Evidence is presented for the structure of a new limonoid, amoorinin, from the stem bark of AMOORA ROHITUKA on the basis of spectral and chemical evidences.