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In the present work, we describe a simple procedure to produce biomimetically coated silver nanoparticles (Ag NPs), based on the postfunctionalization and purification of colloidal silver stabilized by citrate. Two biological capping agents have been used (cysteine Cys and glutathione GSH). The composition of the capped colloids has been ascertained by different techniques and antibacterial tests on GSH-capped Ag NPs have been conducted under physiological conditions, obtaining values of Minimum Inhibitory Concentration (MIC) of 180 and 15 μg/mL for Staphylococcus aureus and Escherichia coli, respectively. The antibacterial activity of these GSH capped NPs can be ascribed to the direct action of metallic silver NPs, rather than to the bulk release of Ag(+).

Functional and bioactive properties of a selection of chitosan and hyaluronic acid grades were compared to enable a rational choice of the best candidate for the future development of mucoadhesive systems intended for the treatment of buccal or vaginal mucositis. Chitosan or hyaluronic acid molecular weight, type of salt and the pH of the administration site were considered as critical variables for functional and bioactive polymer properties. Two grades of chitosan, salified with ascorbic acid or hydrochloric acid, and two grades of sodium hyaluronate were examined. Aqueous solutions (1 % w/w) of each polymer grade or salt were prepared and compared for viscosity, mucoadhesive (tensile stress measurements), antimicrobial, antioxidant and tissue repairing properties. The overall comparison of the results indicates that the high molecular weight of chitosan ascorbate is the more promising candidate for the development of mucoadhesive formulations, characterized by bioactive properties.

Badam Talkh kuhi is an endemic species of Iran commonly used by native people as anti-inflammatory and an- timicrobial remedy. The present study was aimed at investigating the folk claims of this plant, identified by us as Amygdalus lycioides Spach. Several extracts were prepared using various extraction procedures combined with solvents of different polarity. A decoction was firstly prepared according to the procedure of the folk medicine. Maceration (ME), Ul- trasound-Assisted Extraction (USAE) and Microwave-Assisted Solvent Extraction (MASE) were then experimented using pure methanol (MeOH) and n-hexane-acetone (n-Hex-Ac, 50% v/v). Concerning biological investigation, the antimicro- bial potential of all extracts was firstly evaluated by employing the growth inhibition test. Then, the free radical scaveng- ing effect of each extract was measured, given that reactive oxygen species (ROS) are involved in TNF� -induced signal- ing pathways associated with inflammation. Finally, the anti-TNFactivity of the most active extracts was evaluated us- ing in vitro and in vivo assays. Regarding the anti-inflammatory activity, decoction and MASE n-Hex/Ac extract inhibited the production of TNFwith IC50 in the range of 120-390 � g/ml and 6-20 � g/ml, respectively. Interestingly, after oral administration in mice, MASE n-Hex/Ac extract was effective in reducing TNFof about 60%. Moreover, treated animals did not show any signs of toxicity. Results herein reported clearly evidenced that Amygdalus lycioides Spach could be a valuable source of TNF� -blockers effective against chronic inflammatory diseases.

Aims: The aim of our study was to investigate indoor air quality (IAQ) by comparing pyrogen concentration and microbiological contamination in offices in public buildings. Methods and Results: Air samples were collected during cold and warm seasons in 39 offices in four European cities. Pyrogens were measured by the in vitro pyrogen test (IPT), moulds and bacteria by classical microbiology. In 92% of the investigated offices, pyrogen and microbial contaminations were below 150 EEU m−3 and 103 CFU m−3, respectively, whilst in 75%, moulds did not exceed 102 CFU m−3. Conclusions: The IPT is a rapid, reliable tool for measuring pyrogens that could be used as an ‘early warning’ indicator of IAQ. Significance and Impact of the Study: This is the first study on pyrogenic compound detection in offices using IPT, which could serve for developing future indoor air guidelines.

The aim of the present work was the development of a thermally sensitive mucoadhesive gel based on chitosan derivatives for the treatment of oral mucositis. Trimethyl chitosan (TMC) and methylpyrrolidinone chitosan (MPC) were considered. They were mixed with glycerophosphate (GP) according to different polymer/GP molar ratios and characterized for gelation properties by means of rheological analysis in comparison with chitosan. The influence of molecular weight and substitution degree (SD) of TMC on gelation temperature and time was investigated. The mucoadhesive properties of the mixtures were also assessed using porcine buccal mucosa. The best properties were shown by TMC with high MW and low SD mixed with GP according to 1:2 molar ratio. Such mixture was loaded with benzydamine hydrochloride, an anti-inflammatory drug with antimicrobial properties and subjected to in vitro drug release and wash away test. The formulation based on TMC/GP mixture was able to prolong drug release and to withstand the removal physiological mechanisms. The antimicrobial properties of both vehicle and formulation were investigated. Also in absence of drug, TMC/GP mixture was characterized by antimicrobial properties.

Coffee brew is a widely consumed beverage with multiple biological activities due both to naturally occurring components and to the hundreds of chemicals that are formed during the roasting process. Roasted coffee extract possesses antibacterial activity against a wide range of microorganisms, including Staphylococcus aureus and Streptococcus mutans, whereas green coffee extract exhibits no such activity. The naturally occurring coffee compounds, such as chlorogenic acids and caffeine, cannot therefore be responsible for the significant antibacterial activity exerted by coffee beverages against both bacteria. The very low minimum inhibitory concentration (MIC) found for standard glyoxal, methylglyoxal, and diacetyl compounds formed during the roasting process points to these alpha-dicarbonyl compounds as the main agents responsible for the antibacterial activity of brewed coffee against Sa. aureus and St. mutans. However, their low concentrations determined in the beverage account for only 50% of its antibacterial activity. The addition of caffeine, which has weak intrinsic antibacterial activity, to a mixture of alpha-dicarbonyl compounds at the concentrations found in coffee demonstrated that caffeine synergistically enhances the antibacterial activity of alpha-dicarbonyl compounds and that glyoxal, methylglyoxal, and diacetyl in the presence of caffeine account for the whole antibacterial activity of roasted coffee.

Wine contains a number of biologically active compounds with beneficial effects on human health. The antibacterial action of commercial red and white wines against oral streptococci responsible for caries development and against S. pyogenes responsible for pharyngitis was studied. Its postcontact effect against S. mutans was also studied. Both wines displayed activity. The compounds responsible for such activities were succinic, malic, lactic, tartaric, citric, and acetic acid. The synthetic mixtures of the organic acids tested at the concentrations found in wine had greater antibacterial activity than the beverages, indicating that in wine they are inhibited by other components. Wine polyphenols displayed no activity against oral streptococci or S. pyogenes. Findings show that wine is active against oral streptococci and S. pyogenes and suggest that it enhances oral health.

C. DACARRO, P. GRISOLI, G. DEL FRATE, S. VILLANI, E. GRIGNANI AND D. COTTICA. 2004. Aims: In order to assess possible occupational risk for workers in a grain mill, we evaluated aerial microbiological contamination in different areas of the mill and at different points of the production line. We also measured the concentration of aerodispersed dust particles. Methods and Results: An assessment of microbiological contamination levels based on a Global Index of Microbial Contamination per cubic metre (GIMC per m 3 ), an Index of Mesophilic Bacterial Contamination, and an Amplification Index is proposed. The indices were obtained from total and fungal counts. The cleaning sector is the most contaminated area of the mill: the mean GIMC per m 3 was 17 213AE6. In this area, the average microbial contamination was 11AE41 times higher than that in the external environment. The highest concentrations of aerodispersed dust (inhalable 2AE763 mg m )3 ; respirable 1AE400 mg m )3 ) were found in the cleaning area. Conclusions: The proposed microbiological indices and the concentrations of aerodispersed dust particles show that the most hazardous section of the mill is the cleaning area. The large variation in the data does not depend on seasonal factors, but rather on not easily identifiable conditions of the internal environment which facilitate diffusion and/or proliferation of the micro-organisms. Significance and Impact of the Study: The proposed microbiological contamination indices and the evaluation of the concentration of dust particles allow the identification of critical positions during the production cycle so that suitable measures to prevent the aerial contamination can be taken.

Aims: To assess the microbiological indoor air quality (IAQ) of high school and college gyms during physical training lessons and to evaluate the effective microbiological exposure of students. Methods and Results: Air samples from 11 high school and college gyms of Pavia, Italy were collected. Total bacterial counts, total fungal counts and characterization of fungal taxa were determined. Air quality was evaluated using three microbiological contamination indices: the global index of microbiological contamination per m3 (GIMC per m3), the index of mesophilic bacterial contamination (IMC) and the amplification index (AI). Conclusions: This work testifies that air contamination in indoor gyms is always superior to that of the outdoor environment. Nevertheless, students are exposed to relatively low concentrations of airborne micro-organisms. The highest values of fungal counts and GIMC per m3 (>14 661) were observed between April and October when the central heating systems were switched off. The lowest fungal counts were detected in modern buildings equipped with forced ventilation systems. From qualitative aeromycological studies, 45 fungal taxa were identified, and different potentially allergenic species were isolated. Significance and Impact of the Study: The standardization of air sampling methods and the correct evaluation of aeromicrobiological results allow the classification of indoor air healthiness. The proposed microbiological contamination indices together with the characterization of airborne fungal taxa are useful tools for detailed description of IAQ.

Green and roasted coffees of the two most used species, Coffea arabica and Coffea robusta, several commercial coffee samples, and known coffee components were analyzed for their ability to interfere with Streptococcus mutans' sucrose-independent adsorption to saliva-coated hydroxyapatite (HA) beads. All coffee solutions showed high antiadhesive properties. The inhibition of S. mutans' adsorption to HA beads was observed both when coffee was present in the adsorption mixture and when it was used to pretreat the beads, suggesting that coffee active molecules may adsorb to a host surface, preventing the tooth receptor from interacting with any bacterial adhesions. Among the known tested coffee components, trigonelline and nicotinic and chlorogenic acids have been shown to be very active. Dialysis separation of roasted coffee components also showed that a coffee component fraction with 1000 Da < MW < 3500 Da, commonly considered as low MW coffee melanoidins, may sensibly contribute to the roasted coffee's antiadhesive properties. The obtained results showed that all coffee solutions have antiadhesive properties, which are due to both naturally occurring and roasting-induced molecules.

Ethnopharmacological relevance Diospyros bipindensis (Gurke) stem bark is used in Cameroon by Baka Pygmies for the treatment of respiratory disorders. Aim of the study To assess the anti-inflammatory, antibacterial and antioxidant properties of constituents from the bark extracts through bioassay-guided fractionation. Materials and methods The anti-inflammatory activity of extracts, fractions and pure compounds was assessed through the inhibition of the pro-inflammatory mediator nuclear factor-kappa B (NF-κB) transcriptional activity and nitric oxide (NO) production. DPPH, ABTS and ORAC assays were used for determining the antioxidant properties. The activity against Streptococcus pneumoniae, Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli and Klebsiella pneumoniae , was evaluated on the basis of the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) by the macrodilution method. Results The water extract showed antimicrobial activity against S. pneumoniae (MIC: 300 μg/ml) and S. pyogenes (MIC: 300 μg/ml). The dichloromethane extract efficiently inhibited NF-κB transcriptional activity and NO production and exhibited significant antioxidant activity in the ORAC assay. An interesting activity was also found against S. pneumoniae (MIC: 200 μg/ml), S. aureus (MIC: 400 μg/ml) and S. pyogenes (MIC: 200 μg/ml). The phytochemical investigation of the dichloromethane extract afforded plumbagin, canaliculatin, ismailin, betulinic acid and 4-hydroxy-5-methyl-coumarin as the main constituents. Plumbagin and ismailin were found to be responsible for the main biological activities observed. Conclusions These results may provide a rational support for the traditional use of Diospyros bipindensis stem bark in the treatment of respiratory disorders, since the anti-inflammatory, antimicrobial and antioxidant compounds isolated from the dichloromethane extract were also present in the traditional water extract.

Ethnopharmacological relevance The plants of the genus Phyllanthus (Euphorbiaceae) are widely distributed in most tropical and subtropical countries, and have long been used in folk medicine to treat several diseases. Particularly, Phyllanthus muellerianus (Kuntze) Excell, commonly called “mbolongo” in Cameroon, is used by pygmies baka as a remedy for tetanus and wound infections. Aim of the study To investigate the antimicrobial properties of Phyllanthus muellerianus (Kuntze) Excell (family Euphorbiaceae) stem bark used in Cameroon by baka pygmies as a remedy for wound healing and tetanus. Materials and methods Aqueous and methanol extracts with and without defatting treatment, were prepared and their activity against Clostridium sporogenes ATCC 3584, Staphylococcus aureus ATCC 6538, Streptococcus mutans ATCC 25175, Streptococcus pyogenes ATCC 19615, Escherichia coli ATCC 10536, Candida albicans ATCC 10231, was evaluated on the basis of the minimum inhibitory concentration (MIC) and the minimum bactericidal-fungicidal concentration (MBC-MFC) by the macrodilution method. Results Water extract showed a weak activity against Clostridium sporogenes (MIC 900 μg/mL) and resulted inactive at the tested concentrations against all the other microorganisms. The defatted methanol extract, inactive against Staphylococcus aureus , Escherichia coli , Candida albicans , exhibited a very interesting activity against Clostridium sporogenes and Streptococcus pyogenes (MIC 100 μg/mL and 300 μg/mL, respectively), which seems to validate the use of this plant in pygmies traditional medicine for the treatment of tetanus and wound infections. The activity found against Streptococcus mutans (300 μg/mL), aetiological agent of caries, may suggest a possible use of this plant as natural remedy to prevent dental diseases. Conclusions The activity against streptococci and Clostridium sporogenes ATCC 3584, showed by stem bark extracts of Phyllanthus muellerianus , traditionally used by baka pygmies to treat wound infections and tetanus, is reported for the first time.

The proliferation of air-diffused microorganisms inside public buildings such as schools, hospitals, and universities, is often indicated as a possible health risk. In this research, we have illustrated the results of an investigation realized to determine the health of the air in some university classrooms, both from a microbiological and a microclimatic viewpoint, during the normal didactic activity of direct lessons. The results obtained have been expressed by means of contamination indices, already used in previous works. Very little contamination was recorded in the different phases of air treatment, which underlines the efficiency of the system and of the maintenance protocols. The Global Index of Microbial Contamination (GIMC per cubic meter) showed a value greater than the mean during the heating period (290), while the highest values (95th percentile 1,138.45) were recorded in the period using air conditioning. The index of mesophilic bacterial contamination, though it did not show any significant differences in the various modes of air treatment, showed a mean value (1.34) and the 95th percentile value (4.14), which was greater in the air-conditioning phase. Finally, the mean value of the amplification index underlined a decrease in the microbial contamination in comparison to the outside, while showing situations of increased microbial amplification during the period of simple ventilation (95th percentile 4.27). The 95th percentile values found for GICM in the three sampling periods, however, permitted us to identify the value of GIMC per cubic meter equal to 1,000 as a guide to provide a means of self-monitoring the quality of the air inside the classrooms. From a microclimatic viewpoint, two periods of the year manifested discomfort situations: during the heating phase (winter) and during the simple ventilation phase (spring). The results obtained indicate, therefore, a need to intervene on the environmental parameters, not being able, in this particular case, to intervene on other aspects that influence the microclimate.

Los principales componentes identificados en el aceite esencial de las hojas de Ocotea quixos (Lam.) Kosterm. son: Cariofileno 19,029%, Humuleno 14,323% y Eremofileno 11,407%, aclarándose que éstos sobresalen de un total de 62 compuestos. La técnica utilizada para la extracción del aceite fue destilación con agua y vapor de agua, empleando un destilador de 250 litros de capacidad. La cantidad de aceite obtenida fue de 3 ml por cada 10 kg de hojas frescas. El aceite fue utilizado para un experimento de evaluación de actividad antimicrobiana y antifúngica, siendo el resultado la inhibición del crecimiento de cepas de Staphylococcus epidermidis, Staphylcoccus aureus, Escherichia coli, Candida albicans, Streptococos piogenes y Streptococcus mutans. Los resultados del experimento demostraron que el aceite foliar tiene una alta capacidad inhibitoria contra hongos (levaduras) y bacterias; así, se recomienda por un lado, continuar con análisis químicos más finos para determinar la naturaleza específica de los 62 compuestos y, por el otro, realizar ensayos con un número mayor de agentes patógenos.

In order to assess the potential exposure hazard to workers and people living in the immediate surroundings of an area characterized by an open composting facility and a wastewater treatment plant, a quantitative and a qualitative analysis of airborne microorganisms were carried out. Air sampling was performed once a week for four consecutive weeks in summer and winter. Six sites were selected as air sampling sites: one was upwind at approximately 40 m from the facilities; the other five were downwind at increasing distances from the facilities, with the furthest at 100 m away. Monitoring permitted us to verify the influence that the composting activities and wastewater treatment had on the bacterial and fungal contamination of the air. The results obtained have been expressed by means of contamination indexes that have already been used in previous works: a major microbiological contamination near the plants was evidenced. Near the facilities, mesophilic bacteria, psychrophilic bacteria and microfungi showed the highest median concentrations, respectively, of 307.5, 327.5 and 257.5 CFU/m(3). Moreover, the season generally influenced the concentration of the bacteria as well as of the fungi; higher in summer than in winter. The contamination index global index of microbial contamination (GIMC/m(3)) showed mean values of 4058.9 in summer and 439.7 in winter and the contamination index-amplification index (AI) showed values of 4.5 and 1.1 in the same seasons, respectively. Controlling the seasonal effect, mesophilic bacteria, Pseudomonas spp. and Enterobacteriaceae showed a significant decline in concentration with respect to upwind air samples and with increasing distance. Both GIMC and AI showed a significant decline with respect to upwind air samples by increasing the distance from facilities after adjusting for the seasonal effect. In conclusion, even if these plants do not represent a potential risk for nearby populations, they may pose a potential health risk for workers.

Aim of the study Bridelia grandis (Pierre ex Hutch) (Euphorbiaceae) is a medicinal plant traditionally used in Cameroon by pygmies Baka as a remedy for oral cavity affection. Bioassay-guided stem bark extracts were investigated for their in vitro antimicrobial properties as well as their phytochemical constituents. Materials and methods The first extraction was carried out according to the traditional use. Further extractions were carried out with solvents of different polarity such as methanol (MeOH), ethyl acetate (EtOAc) and mixtures of MeOH–H 2 O. The antimicrobial activity of the extracts against oral Streptococci was evaluated on the basis of the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) by the macrodilution method; the bacterial surface hydrophobicity was also evaluated. Results Water, methanol and mixtures methanol–water extracts, exhibited antibacterial activity with MIC between 0.5 and 2 mg/ml justifying the traditional use of Bridelia grandis stem bark for oral cavity affection. Preliminary phytochemical analysis was performed on the most active extract (methanol) using appropriate tests and well established analytical screening methods, such as TLC and RP-HPLC/DAD. Conclusions The data obtained indicate that tannins constitute the chemical family responsible for the biological activity.

El estudio de la composición química del aceite esencial de la planta reconocida con el nombre vernáculo de arrayán y que pertenece a la especie Myrcianthes rhopaloides (Kunth in H.B.K.) McVaugh, familia Myrtaceae, fue realizado mediante la técnica de cromatografía de gases acoplada a masas, la que permitió identificar una mezcla de componentes mono y sesquiterpenos. Es así, que los principales compuestos que se destacaron fueron Linalol, Eucaliptol, D –Limoneno y Terpineol; seguidos, en menor proporción, de 4 Terpineol, cis Mirtanol, Cariofileno, ·-Cariofileno, Cadineno y Espatulenol.El efecto de la actividad antimicrobiana del aceite de arrayán evidenció una acción fuerte sobre microorganismos como Streptococcus mutans y Streptococcus pyogenes, menor sobre Staphilococcus aureus y Staphilococcus epidermidis, y ausente sobre Escherichia coli y Candida albicans.

Some beverages and foods protect tooth surfaces against Streptococcus mutans colonization. Adhesion of S. mutans is a crucial step in the initiation and development of dental caries. In this study, we showed that barley coffee (BC), a beverage made from roasted barley, interferes with S. mutans adsorption to hydroxyapatite (HA), and we identified its antiadhesive components. The effects of sublethal concentrations (sub-MICs) of BC on the adhesion of S. mutans to saliva-coated HA beads were assessed using three experimental approaches: (A) Beads were pretreated with BC before adding bacteria, (B) BC and bacteria were added to the beads simultaneously, and (C) streptococci grown in the presence of sub-MICs of BC were added to the beads. All treatments induced variable but significant inhibition of S. mutans sucrose-dependent and -independent adherence to HA. Similar results were obtained with other oral streptococci. BC components were fractioned by dialysis and gel filtration chromatography; the 1000 kDa MM fraction, which consists of a potent brown antioxidant, melanoidin, both displayed antiadhesive properties. High-MM melanoidin was not detected in unroasted barley, indicating that it forms during the roasting process. Results suggest that BC consumption may influence the colonization of tooth surfaces by cariogenic bacteria.

The antiradical activity of water soluble components in six vegetables belonging to the Cichorium genus, i.e., three cultivars of red intybus species var. silvestre (Treviso, Chioggia, Verona red chicories), a white intybus species var. foliosum (Belgian chicory), and two vegetables of the endivia species var. latifolium (escarole chicory) and var. crispum (‘‘crispa’’ chicory), were studied using two biological systems consisting of: (1) microsome membrane rat hepatocyties in which oxidative damage was induced by CCl4; (2) gram-positive bacterium, Staphylococcus aureus cultures, subjected to damage with cumene hydroperoxyde. The obtained results show that in both systems the red vegetables possess the strongest antioxidant properties and contain different antioxidant compounds whether at a low or high molecular weight, but only those of high molecular-weight (MW > 3500 Da) are able to act as antioxidants in all the used systems. The lower MW fraction (MW < 3500 Da) showed itself to be pro-oxidant in the microsome system. The effects of thermal treatments such as boiling, freezing and freeze-drying were also investigated.

This research demonstrates that roasted coffee has antibacterial properties. This activity is evident against a wide range of bacteria. In particular, the study considered the effect on such activity of three variables: coffee variety (Coffea arabica and Coffea robusta, from a total of 10 different sources), the degree of roasting (light, medium, and dark), and, finally, differences in brewing procedure. All of the roasted coffee samples examined clearly show antibacterial activity, and this activity mainly depends on the degree of roasting. This result shows that the main causes of the antibacterial activity of coffee are substances produced by the roasting process such as Maillard reaction products, carbohydrate caramelization, and thermal decomposition products

A coffee beverage obtained from instant dark coffee that had been previously shown to possess high antibacterial activity, was acidified (pH 2) and extracted with ethyl acetate. After alkalinization (pH 12) the aqueous phase was re-extracted with the organic solvent. The acidic and basic extracts were evaporated to dryness and the aqueous phase freeze-dried. Residues were dissolved in sterile water and assayed for antibacterial activity against two reference bacteria (Staphylococcus aureus ATCC 25923 and Streptococcus mutans 9102). The acidic extract was found to be highly active and was separated by gel permeation chromatography (GPC) into five fractions. Fractions GPC4 and GPC5 were found to possess antibacterial activity: most of the activity was evident in fraction GPC5. These fractions were separated by RP-HPLC using a gradient elution with methanol–water as mobile phase. Both GPC fractions gave an active subfraction with methanol–water (70:30, v/v). The experimental conditions used to separate the antibacterial compound that originates during the roasting process, indicate that it possesses low molecular mass (probably no more than 200 Da), weak acidic properties and an λmax at 205 nm. The very small amount of this compound isolated from roasted coffee, indicates that it may be a very strong antibacterial agent.

The antibacterial activity of coffee depends mainly on the degree of roasting of the coffee beans. To identify easily determinable chemical markers which relate to coffee's antibacterial activity, 5-caffeoylquinic acid, caffeic acid, nicotinic acid, trigonelline, 5-(hydroxymethyl)furfuraldehyde, the content of which changed throughout the roasting process, and caffeine were considered. A new HPLC method that allows determination of these compounds simultaneously was developed. Two antibacterial activity chemical markers were found: (1) the sum of trigonelline and nicotinic acid contents and (2) the 5-caffeoylquinic acid/caffeine ratio