Anti-inflammatory, antimicrobial and antioxidant activities of Diospyros bipindensis (Gürke) extracts and its main constituents.

ETHNOPHARMACOLOGICAL RELEVANCE: Diospyros bipindensis (Gürke) 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.

Antimicrobial properties of stem bark extracts from Phyllanthus muellerianus (Kuntze) Excell.

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.

Pyrogenic activity of air to characterize bioaerosol exposure in public buildings: a pilot study.

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 10(3) CFU m(-3), respectively, whilst in 75%, moulds did not exceed 10(2) 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.

Thermally sensitive gels based on chitosan derivatives for the treatment of oral mucositis.

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 1:2molar 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.

Validation of use of a traditional remedy from Bridelia grandis (Pierre ex Hutch) stem bark against oral Streptococci.

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-H2O. 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 2mg/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.

Micro-organisms and dust exposure in an Italian grain mill.

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 m3), 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 m3 was 17,213.6. In this area, the average microbial contamination was 11.41 times higher than that in the external environment. The highest concentrations of aerodispersed dust (inhalable 2.763 mg m(-3); respirable 1.400 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.

Determination of aerial microbiological contamination in scholastic sports environments.

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.

Antiadhesive effect of green and roasted coffee on Streptococcus mutans' adhesive properties on saliva-coated hydroxyapatite beads.

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.

[Proposed microbiological indexes for the assessment of air quality in buildings]. / Proposta di indici microbiologici per la valutazione della qualità dell'aria degli edifici.

An assessment of biological risk in the workplace requires the measurement of microorganisms present in the air. Although it is currently difficult to establish a dose-response relationship on the basis of existing epidemiological data, the number and types of microorganisms present offer a useful index when evaluating the quality of the air. Using the results obtained from a study of 226 different offices located in buildings equipped with forced ventilation we propose an assessment of contamination levels based on a Global Index of Microbial Contamination/m3 (GIMC/m3). This index is calculated as the sum of the values of the total microbial count determined for mesophilic bacteria, psychrophilic bacteria and fungi in all sampled areas. GIMC/m3 fluctuates between a minimum value of 23 and a maximum value of 18.069: the mean value varies depending on the ventilation system mode setting, with a value of 145 when operating in the heating mode, 265 in the air-conditioning mode and 258 under simple forced ventilation. 95.5% of the offices under study had a GIMC/m3 value of below 1000: this value is proposed as a threshold limit above which a more extensive assessment of contamination levels based on the measurement of further microbiological indexes should be carried out. To this aim we propose an Index of Mesophilic bacterial Contamination (IMC), obtained by calculating the ratio between the CFU/m3 value measured for mesophilic and psychrophilic bacteria in the same sampling point. The measurement of the Amplification Index (AI) completes the evaluation and this is determined by calculating the ratio between the GICM/m3 values measured inside the building and those measured outside. When considering these observations as a whole we are able to classify the various work areas under study into groups and categories according to the observed values of the proposed microbial contamination indexes.

Isolation of an antibacterial component from roasted coffee.

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 lambda(max) at 205 nm. The very small amount of this compound isolated from roasted coffee, indicates that it may be a very strong antibacterial agent.