ABSTRACT
Objective: To investigate the antibiofilm activity of alpha-mangostin (AMG) loaded nanoparticle (nanoAMG) against dental caries pathogen Streptococcus mutans. Methods: AMG was isolated from the peels of Garcinia mangostana L. using silica gel columns and chemically analysed by high performance liquid chromatography and nuclear magnetic resonance. NanoAMG was prepared using the solvent evaporation method combined with high-speed homogenization. The nanoparticles were characterized using dynamic light scattering, field emission scanning electron microscopy (FE-SEM) and Fourier transform infrared spectroscopy (FTIR). The toxicity of nanoAMG in fibroblast NIH/3T3 cell line was determined using MTT method. The antibiofilm effect of nanoAMG was determined through the evaluation of biofilm formation by Streptococcus mutans using a 96-well plate. Biofilm biomass was quantified using crystal violet. Cell viability was observed under confocal microscopy using LIVE/DEAD BacLight staining. Moreover, gene expression was determined by quantitative real-time PCR and membrane permeabilization activity by measuring the uptake of o-nitrophenol-β-D-galactoside. Results: NanoAMG size was in a range of 10-50 nm with a polydispersity index of < 0.3 and zeta potential value of -35.2 mV. The size and the incorporation of AMG in the nanoparticles were confirmed by FE-SEM and FTIR analyses. The IC50 values of the test agents on NIH/3T3 cells were (9.80 ± 0.63) μg/mL for AMG and (8.70 ± 0.81) μg/mL for nanoAMG, while no toxicity was generated from excipients used to prepare nanoparticles. In the early stage of biofilm formation, treatment with 6.25 μmol/L nanoAMG caused a reduction in biofilm biomass up to 49.1％, compared to 33.4％ for AMG. In contrast, biofilms at the late stage were more resistant to the test agents. At 96 μmol/L (= 10 × MIC), nanoAMG reduced only 20.7％ of biofilm biomass while AMG did not show any effect. Expressions of gtfB and gtfC genes involved in biofilm formation were down-regulated 3.3 and 12.5 folds, respectively, compared to AMG (2.4 and 7.6 folds, respectively). LIVE/DEAD BacLight fluorescence staining and microscopy observation indicated that biofilm cells were killed by both nanoAMG andAMG at 48 μmol/L (= 5 × MIC). In addition, membrane permeabilization activity was increased in a time dependent manner and higher in nanoAMG treated cells compared toAMG.Conclusions: AMG coated nanoparticle can enhance AMG bioactivity and can be used as a new and promising antibiofilm agent.
ABSTRACT
A study on the species composition and the level of infestation of cockroaches was carried out from April 2013 to October 2014 in three localities of Hanoi, Vietnam, namely the Lan Ong-Old Town, Linh Dam condominium and Tan Da Resort. Out of the 187 units of premises examined, 44.9% of units were infested with cockroaches. A total of 576 cockroaches were trapped, of which six species were identified: Periplaneta americana (L.) was the most dominant species (72.1%), followed by Blattella germanica (L.) (14.8%), Pycnoscelus surinamensis (L.) (7.3%), Periplaneta australasiae (Fabricius) (2.9%), Periplaneta fuliginosa (Serville) (1.9%) and Supella longipalpa (Fabricius) (1.0%). Infestation was the highest in Lan Ong (74.0%), followed by Linh Dam (40.5%) and Tan Da (25.9%). Cockroaches were abundantly found in warehouses (100%), electrical distribution room (56.3%), and kitchens (46.7%).
ABSTRACT
The chemical constituents of essential oils obtained from leaves, stems and roots of Zingiber gramineum Noronha ex Blume and Zingiber rufopilosum Gagnep collected from Vietnam have been studied. The determination of essential oil components was performed by Gas Chromatography-Flame Ionization Detector (GC-FID) and Gas Chromatography- Mass Spectrometry (GC-MS). The main constituents of the leaves oil of Zingiber gramineum were zingiberene (19.5 percent), beta-cubebene (12.9 percent), beta-sesquiphellandrene (12.9 percent) and beta-elemene (11.6 percent) while the stems oil was dominated by benzyl benzoate (22.6 percewnt), beta-elemene (9.7 percent) and beta-selinene (8.8 percent). However, upsilon-terpinene (17.9 percent), alpha-terpinene (17.1 percent), terpinen-4-ol (13.0 percent) and 1,8-cineole (12.8 percent) were the present in the root oil. In addition, beta-agarofuran (13.7 percent), alpha-humulene (8.8 percent) and alpha-pinene (8.7 percent) were the main compounds identified in the leaves of Zingiber rufopilosum. The stems comprised of alpha-cadinol (15.1 percent), beta-muurolol (12.1 percent) and endo-1-bourbonanol (9.9 percent) while (E,E)-farnesol (11.6 percent), alpha-pinene (10.0 percent), bornyl acetate (6.6 percent) and beta-pinene (6.2 percent) were the significant compounds of the root oil. This is the first report on the volatile compositions of these plant species.
El presente estudio se llevó a cabo para evaluar el efecto del extracto metanólico acuoso a partir de los componentes químicos de los aceites esenciales obtenidos de las hojas, tallos y raíces de Zingiber gramineum Noronha ex Blume y Zingiber rufopilosum Gagnep recogidos de Vietnam. La determinación de componentes de aceites esenciales se realizó por cromatografía de gases-detector de ionización de llama (GC-FID) y cromatografía de gases espectrometría de masas (GC-MS). Los principales componentes del aceite de hojas de Zingiber gramineum fueron zingibereno (19,5 por ciento), beta-cubebene (12,9 por ciento), beta-sesquiphellandrene (12,9 por ciento) y beta-elemene (11,6 por ciento), mientras que el aceite de tallos fue dominada por benzoato de bencilo (22,6 por ciento), beta-elemene (9,7 por ciento) y beta-selineno (8,8 por ciento). Sin embargo, ipsilon-terpineno (17,9 por ciento), alfa-terpineno (17,1 por ciento), terpinen-4-ol (13,0 por ciento) y 1,8-cineol (12,8 por ciento) fueron los presentes en el aceite de la raíz. Además, beta-agarofuran (13,7 por ciento), alfa-humuleno (8,8 por ciento) y alfa-pineno (8,7 por ciento) fueron los principales compuestos identificados en las hojas de Zingiber rufopilosum. Los tallos componen de alfa-cadinol (15,1 por ciento), beta-muurolol (12,1 por ciento) y endo-1-bourbonanol (9,9 por ciento), mientras que (E, E)-farnesol (11,6 por ciento), alfa-pineno (10,0 por ciento), acetato de bornilo (6,6 por ciento) y beta-pineno (6,2 por ciento) fueron los compuestos significativos del aceite de la raíz. Este es el primer informe sobre las composiciones volátiles de estas especies de plantas.
Subject(s)
Oils, Volatile/chemistry , Plant Leaves/chemistry , Zingiberaceae/chemistry , Chromatography, Gas/methods , Monoterpenes/analysis , Plant Roots/chemistry , Plant Stems/chemistry , Sesquiterpenes/analysisABSTRACT
Two hundred and sixty married women seeking induced abortion service in Hanoi, Vietnam were interviewed to determine the magnitude of repeat induced abortion and explore selected characteristics of the repeat aborters. Seventy-one percent of the sample reported having had at least one previous induced abortion. After adjustment for age and number of living children, poor attitudes toward contraception, low use of modern contraceptives and failure of contraception were shown to be significantly associated with repeat induced abortion. Woman's age, number of living children, contraceptive knowledge and experience and desire for no more children were positively related to repeat induced abortion. Socio-demographic characteristics were not related to repeat induced abortion. Improvement of attitudes toward contraception, persuasion to use modern contraception and promotion of contraceptive effectiveness are recommended strategies to prevent repeat induced abortion.