We selected Pleurotus ostreatus from among several edible mushrooms because it has high anti-gout xanthine oxidase (XOD) inhibitory activity. The maximal amount of XOD inhibitor was extracted when the Pleurotus ostreatus fruiting body was treated with distilled water at 40℃ for 48 hr. The XOD inhibitor thus obtained was purified by Sephadex G-50 gel permeation chromatography, ultrafiltration, C18 solid phase extraction chromatography and reverse-phase high-performance liquid chromatography with 3% of solid yield, and its XOD inhibitory activity was 0.9 mg/mL of IC50. The purified XOD inhibitor was a tripeptide with the amino acid sequence phenylalanine-cysteine-histidine and a molecular weight of 441.3 Da. The XOD inhibitor-containing ultrafiltrates from Pleurotus ostreatus demonstrated dose-dependent anti-gout effects in a Sprague-Dawley rat model of potassium oxonate-induced gout, as shown by decreased serum urated levels at doses of 500 and 1,000 mg/kg, although the effect was not as great as that achieved with the commercial anti-gout agent, allopurinol when administered at a dose of 50 mg/kg.

BackgroundPovidone‐iodine (PVP‐I) is well known as an antiseptic and exhibits extensive activity against various pathogens. However, due to its uniquely unpleasant nature, it cannot be used locally to deactivate various sinonasal pathogens. Therefore, we developed a PVP‐I composite that blocks the unpleasant odor of PVP‐I for use as a local antiseptic in the sinonasal cavity and evaluated its effect on bacterial biofilm's formation and elimination in in vivo and in vitro models.MethodsMTT, lactate dehydrogenase, and live/dead staining assay were performed to examine the cellular toxicity of PVP‐I composites on the primary human nasal epithelial and RPMI 2650 cells. Crystal violet assay was performed to quantify bacterial biofilm after treating with various agents, including PVP‐I and antibiotics. Hematoxylin‐and‐eosin staining, live/dead staining assay, and scanning electron microscopy were conducted to evaluate the effect of PVP‐I on biofilm formation in a mice biofilm model.ResultsIt was observed that the PVP‐I composite did not have any significant toxic effect on the nasal epithelial cells. Furthermore, the PVP‐I composite effectively inhibited the formation of bacterial biomass within a dose‐dependent manner after 48 hours of incubation with Pseudomonas aeruginosa and Staphylococcus aureus. In mice, it effectively eliminated biofilm from the mucosa of the nasal cavity and maxillary sinus at the tested concentrations.ConclusionThe results of this study indicate that the PVP‐I composite is a promising compound that could be used locally to prevent the formation of biofilms and to eliminate them from the sinonasal cavity.

Staphylococcus aureus (S. aureus) is one of the well-known agents causing atopic dermatitis (AD) in susceptible individuals, and Staphylococcus epidermidis (S. epidermidis) produces class I thermostable bacteriocins that can selectively kill S. aureus, suggesting protective roles against AD. There is a large need for developing precise therapies only to target S. aureus and not to harm the beneficial microbiome. On the agar well diffusion assay, live planktonic S. epidermidis showed clear zones of inhibition of S. aureus growth, but heat-killed cells and cell-free supernatants did not show this. These results would lead us to hypothesize that cytoplasmic bacteriocin from S. epidermidis will be a promising agent to inhibit S. aureus growth. Therefore, we have extracted a novel thermolabile cytoplasmic bacteriocin from S. epidermidis using trichloroactic acid (TCA)/acetone precipitation method after cell lysis with a SDS-containing buffer. These bacteriocin selectively exhibited antimicrobial activity against S. aureus and methicillin-resistance Staphylococcus aureus (MRSA), presenting no active actions against S. epidermidis, E. coli, and Salmonella Typhimurium. The extracted cytoplasmic bacteriocin compounds revealed several diffuse bands of approximately 40–70 kDa by SDS-PAGE. These findings suggest that these cytoplasmic bacteriocin compounds would be a great potential means for S. aureus growth inhibition and topical AD treatment.

: Fibrinolytic activities of culture concentrates of various yeasts were investigated. The concentrates of the culture broth of Saccharomyces cerevisiae Y99-7 showed the strongest fibrinolytic activity of 25 mm (clear zone). The fibrinolytic activity of Saccharomyces cerevisiae Y99-7 was more high in the culture concentrates from PD broth rather than that of yeast extract-peptone dextrose cultures (clear zone : 22.7 mm).

Kluyveromyces fragilis KCTC 7260 and Saccharomyces cerevisiae KCTC 7904, which both grew well in pear marc extract, were selected and their growth profiles and physiological functionalities were determined. Both of the selected yeasts established maximal growth by 20 hr of cultivation at 30℃ in pear marc extract. The cell-free extracts showed high antihypertensive angiotensin I-converting enzyme inhibitory activity of 68.9% and 52.1%, respectively. The extracts also displayed 9.2 U/mL and 12.0 U/mL of protease activity, respectively.

Although Mycobacterium tuberculosis (Mtb) is an intracellular pathogen in phagocytic cells, the factors and mechanisms by which they invade and persist in host cells are still not well understood. Characterization of the bacterial proteins modulating macrophage function is essential for understanding tuberculosis pathogenesis and bacterial virulence. Here we investigated the pathogenic role of the Rv2145c protein in stimulating IL-10 production. We first found that recombinant Rv2145c stimulated bone marrow-derived macrophages (BMDMs) to secrete IL-10, IL-6 and TNF-α but not IL-12p70 and to increase the expression of surface molecules through the MAPK, NF-κB, and TLR4 pathways and enhanced STAT3 activation and the expression of IL-10 receptor in Mtb-infected BMDMs. Rv2145c significantly enhanced intracellular Mtb growth in BMDMs compared with that in untreated cells, which was abrogated by STAT3 inhibition and IL-10 receptor (IL-10R) blockade. Expression of Rv2145c in Mycobacterium smegmatis (M. smegmatis) led to STAT3-dependent IL-10 production and enhancement of intracellular growth in BMDMs. Furthermore, the clearance of Rv2145c-expressing M. smegmatis in the lungs and spleens of mice was delayed, and these effects were abrogated by administration of anti-IL-10R antibodies. Finally, all mice infected with Rv2145c-expressing M. smegmatis died, but those infected with the vector control strain did not. Our data suggest that Rv2145c plays a role in creating a favorable environment for bacterial survival by modulating host signals.

: Physiological functionalities of culture concentrates from various fungi were investigated. The culture concentrates from Saccharomyces cerevisiae Y277-3 showed the highest tyrosinase inhibitory activity of 42.7%. Among mold physiological functionalities, the culture concentrates from Aspergillus orygae CN20-3-1-4 showed the highest antioxidant activity of 15.8%. The other functionalities of fungi were very low or not detected. The intracellular tyrosinase inhibitor from Saccharomyces cerevisiae Y277-3, which showed the highest physiological functionalities was maximally produced when the strain was cultured in PD broth at 30 o C for 24 h.

Atopic dermatitis (AD) is characterized by disturbances in epidermal barrier functions and the hyperactive immune response. Staphylococcus aureus (S. aureus) can be cultured from 90% of AD skin lesions and can exacerbate or contribute to the persistent skin inflammation in AD by secreting toxins with superantigenic properties. Superantigens can induce mast cell (MC) degranulation after penetrating the epidermal barrier. The role of MCs in AD is suggested by the increase in the MC number and MC activation. MCs are activated for degranulation and mediator release by allergens that crosslink IgE molecules or by microbial products. Therefore, MCs may be critically involved in the pathogenesis of AD. However, the understanding mechanisms of MC degranulation by S. aureus in relation to AD have still not been fully elucidated. In this study, we found that live S. aureus or methicillin-resistant S. aureus (MRSA) but not heat-killed bacteria induced MC degranulation. The heat-treatment partially inhibited MC degranulation by conditioned media (CM) of S. aureus or MRSA. The calcium chelator ethylene glycol tetraacetic acid (EGTA) did not block MC degranulation induced by live S. aureus or MRSA, but EGTA-treatment partially inhibited MC degranulation by CM from S. aureus or MRSA. These results suggest that live S. aureus and MRSA can degranulate MCs via direct interaction which may be important role in AD.