Effects of fungal species, cultivation time, growth substrate, and air exposure velocity on the fluorescence properties of airborne fungal spores.

UNLABELLED: Real-time bioaerosol monitoring is possible with fluorescence based instruments. This study provides information on major factors that can affect the fluorescence properties of airborne fungal spores. Two fluorescence-based bioaerosol detectors, BioScout, and ultraviolet aerodynamic particle sizer (UVAPS), were used to study fluorescent particle fractions (FPFs) of released spores of three fungal species (Aspergillus versicolor, Cladosporium cladosporioides, and Penicillium brevicompactum). Two culture media (agar and gypsum board), three ages of the culture (one week, one month, and four months), and three aerosolization air velocities (5, 15, and 27 m/s) were tested. The results showed that the FPF values for spores released from gypsum were typically lower than for those released from agar indicating that poor nutrient substrate produces spores with lower amounts of fluorescent compounds. The results also showed higher FPF values with lower air velocities in aerosolization. This indicates that easily released fully developed spores have more fluorescent compounds compared to forcibly extracted non-matured spores. The FPFs typically were lower with older samples. The FPF results between the two instruments were similar, except with four-month-old samples. The results can be utilized in field measurements of fungal spores to estimate actual concentrations and compare different instruments with fluorescence-based devices as well as in instrument calibration and testing in laboratory conditions. PRACTICAL IMPLICATIONS: Fluorescence-based instruments are the only choice for real-time detection of fungal spores at the moment. In general, all fluorescence-based bioaerosol instruments are tested against known bacterial and fungal spores in laboratory conditions. This study showed that fungal species, growth substrate, age of culture, and air current exposure rate have an effect on detection efficiency of fungal spores in the fluorescence-based instruments. Therefore, these factors should be considered in the instrument calibration process. The results are also important when interpreting results of fluorescence-based field measurements of fungal spores.

Susceptibility of green and conventional building materials to microbial growth.

Green building materials are becoming more popular. However, little is known about their ability to support or limit microbial growth. The growth of fungi was evaluated on five building materials. Two green, two conventional building materials and wood as a positive control were selected. The materials were inoculated with Aspergillus versicolor, Cladosporium cladosporioides and Penicillium brevicompactum, in the absence and presence of house dust. Microbial growth was assessed at four different time points by cultivation and determining fungal biomass using the N-acetylhexosaminidase (NAHA) enzyme assay. No clear differences were seen between green and conventional building materials in their susceptibility to support microbial growth. The presence of dust, an external source of nutrients, promoted growth of all the fungal species similarly on green and conventional materials. The results also showed a correlation coefficient ranging from 0.81 to 0.88 between NAHA activity and culturable counts. The results suggest that the growth of microbes on a material surface depends on the availability of organic matter rather than the classification of the material as green or conventional. NAHA activity and culturability correlated well indicating that the two methods used in the experiments gave similar trends for the growth of fungi on material surfaces.

Inhibition of vascular response in inflammation by crude aqueous extract of the root bark of zanthoxylum xanthoxyloides.

BACKGROUND: The root bark extract of Zanthoxylum xanthozyloides is used in folklore medicine in Ghana and Nigeria to treat inflammation. A previous pharmacological study confirmed the anti-inflammatory activity of the extract. OBJECTIVE: To study the effect of the extract on vascular response in inflammation. METHOD: The extract was obtained by Soxhlet extraction and rotatory evaporation, followed by freeze-drying. Groups of rats (with carrageenin-induced paw inflammation) and mice (with xylene-induced pinna inflammation) were, respectively, assigned randomly to treatment groups. The animals were given three different treatments orally: 0.9% saline (control), the extract (400mg/kg and 800mg/kg for mice; 1000mg/kg, 2000 mg/kg, and 4000mg/kg for rats), and indomethacin (5mg/kg and 10mg/kg for mice; 10mg/kg, 20mg/kg, and 40mg/kg for rats). In another set of experiment, each treatment group received phenylephrine subcutaneously (30µg/kg for rats and 20µg/kg for mice) in addition to the specified treatment aforementioned. In both sets of experiments, each group of rats was rotated through the entire treatment groups such that each animal served as control as well as received all the treatments. Analysis of variance was used as the statistical test. RESULTS: The extract and indomethacin both caused dose-dependent reduction in the carrageenin-induced increase in paw volume in rats and also reduced xylene-induced increase in blood flow in mice pinna arteries. Phenylephrine enhanced the decrease in capillary permeability and vasodilatation caused by low dose extract but not that caused by high dose extract or both low and high dose indomethacin. CONCLUSION: The extract reduced vasodilatation and decreased capillary permeability in inflammation.

Crude aqueous extract of the root bark of zanthoxylum xanthoxyloides inhibits white blood cells migration in acute inflammation.

BACKGROUND: Crude aqueous extract of Zanthoxylum xanthozyloides is used locally to treat inflammatory conditions. Previous study confirmed that the extract has anti-inflammatory activity and also reduced vascular response in inflammation. OBJECTIVE: To identify the effect of the extract on migration of white blood cells to the site of inflammation. METHOD: The extract was obtained by Soxhlet extraction and rotatory evaporation, followed by freeze-drying. Cohorts of Wistar rats (150g - 200g) were randomly assigned to 6 treatment cells, and were given, per os, three different treatments: indomethacin (20mg/kg and 40mg/kg), the extract (2000mg/kg and 4000mg/kg), and 0.9% saline (two groups of control). Inflammation was induced with carrageenin in the hind paw of the treated groups of rats and one group of the control (positive control), one hour after treatment. Inflammatory exudates from the inflamed paws were collected and the white blood cells (WBCs) counted. RESULTS: Carrageenin increased the total WBC count (in the paw fluid) which was reduced by the extract and indomethacin (p<0.05). Neither the extract nor indomethacin had any effect on total WBC count in the non-carrageenin treated control rats. CONCLUSION: The extract did not affect the pre-existing WBC population at the site of inflammation but rather inhibited migration of the cells to the site.

Analgesic activity of crude aqueous extract of the root bark of zanthoxylum xanthoxyloides.

OBJECTIVE: The analgesic activity of crude aqueous extract of the root bark of Zanthoxylum xanthozyloides was studied in mice and rats with the view to verifying the claim in folklore medicine that the extract has analgesic activity. METHOD: The extract was obtained by Soxhlet extraction and rotatory evaporation, followed by freeze-drying. Groups of rats and mice were, respectively, assigned randomly to treatment groups. The animals received three different treatments orally: 0.9% saline (control), the extract (400mg/kg and 800mg/kg for mice; 1000mg/kg and 2000mg/kg for rats) and indomethacin (5mg/kg and 10mg/kg for mice; 10mg/kg and 20mg/kg for rats). Each group of animals was rotated through the entire treatment groups such that each animal served as control as well as received all the treatments. The hot-plate and paw-pressure methods were used to study pain perception in the treated animals. Analysis of variance was used as the statistical test. RESULTS: In both methods, the extract and indomethacin caused dose-dependent elevation in pain threshold. At the peak of activity, 400mg/kg and 800mg/kg extract caused 74% and 95% increase in the reaction time respectively whilst 5mg/kg and 10mg/kg indomethacin gave 97% and 116% increment respectively. Similarly, 1000mg/kg and 2000mg/kg extract caused 65% and 84% increase in pain threshold whilst 10mg/kg and 20mg/kg indomethacin caused 95% and 113% increment respectively. CONCLUSION: It was concluded that the extract induced analgesia, probably, by inhibiting prostaglandin production, just as did indomethacin.

In vivo inhibition of prostaglandin e(2) production by crude aqueous extract of the root bark of zanthoxylum xanthoxyloides.

BACKGROUND: Crude aqueous extract of the root bark of Zanthoxylum xanthoxyloides is used in folklore medicine for its anti-inflammatory activity. Although it shares the analgesic and anti-inflammatory property of non-steroidal anti-inflammatory drugs (NSAIDs), its mechanism of action has not been well elucidated. OBJECTIVE: To ascertain whether the extract decreases carrageenin-induced increase in plasma prostaglandin E(2) (PGE(2)) concentration with the view to shed light on the mechanism of action. METHODS: The extract was obtained by Soxhlet extraction and rotatory evaporation, followed by freeze-drying. Forty Wistar rats (150g - 200g) were assigned to 8 groups of 5 rats each. The rats were given four different treatments orally: 0.9% saline (two groups of control); two groups received indomethacin, 20mg/kg and 40mg/kg respectively; another two groups received the extract, 2000mg/kg and 4000mg/kg respectively; and the remaining two groups, 50mg/kg and 100mg/kg nimesulide respectively. Inflammation was induced with carrageenin in one of the two groups of control. Enzyme-linked immunospecific assay was used to measure plasma PGE(2) concentration in the control and treated groups of rats. Analysis of variance was used as the statistical test. Differences in means at p<0.05 were considered significant. RESULTS: Carrageenin increased plasma PGE(2) concentration which was reduced by the extract, indomethacin and nimesulide. High dose extract and indomethacin reduced plasma PGE(2) concentration to a comparable extent which was much greater than that of the reduction caused by nimesulide. CONCLUSION: It was concluded that the extract might act by non-selective inhibition of cyclooxygenase 1 and 2 to decrease plasma PGE(2) concentration.