• Journal of Microbiology and Biotechnology
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• v.17 no.11
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• pp.1797-1804
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• 2007

Lycopene, an acyclic carotenoid found in tomatoes (Lycopersicon esculentum) and a number off fruits, has shown various biological properties, but its antifungal effects remain poorly understood. The current study investigated the antifungal activity of lycopene and its mode of action. Lycopene showed potent antifungal effects toward pathogenic fungi, tested in an energy-independent manner, with low hemolytic effects against human erythrocytes. To confirm the antifungal effects of lycopene, its effects on the dimorphism of Candida albicans induced by fetal bovine serum (FBS), which plays a key role in the pathogenesis of a host invasion, were investigated. The results showed that lycopene exerted potent antifungal activity on the serum-induced mycelia of C. albicans. To understand the antifungal mode of action of lycopene, the action of lycopene against fungal cell membranes was examined by FACScan analysis and glucose and trehalose-release test. The results indicated that lycopene caused significant membrane damage and inhibited the normal budding process, resulting from the destruction of membrane integrity. The present study indicates that lycopene has considerable antifungal activity, deserving further investigation for clinical applications.

• Journal of Microbiology and Biotechnology
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• v.20 no.10
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• pp.1397-1402
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• 2010

Papyriflavonol A (PapA), a prenylated flavonoid [5,7,3',4'-tetrahydroxy-6,5'-di-(${\gamma},{\gamma}$-dimethylallyl)-flavonol], was isolated from the root barks of Broussonetia papyrifera. Our previous study showed that PapA has a broad-spectrum antimicrobial activity against pathogenic bacteria and fungi. In this study, the mode of action of PapA against Candida albicans was investigated to evaluate PapA as an antifungal agent. The minimal inhibitory concentration (MIC) values were 10~25 ${\mu}g/ml$ for C. albicans and Saccharomyces cerevisiae, Gram-negative bacteria (Escherichia coli and Salmonella typhimurium), and Gram-positive bacteria (Staphylococcus epidermidis and Staphylococcus aureus). The kinetics of cell growth inhibition, scanning electron microscopy, and measurement of plasma membrane florescence anisotrophy revealed that the antifungal activity of PapA against C. albicans and S. cerevisiae is mediated by its ability to disrupt the cell membrane integrity. Compared with amphotericin B, a cell-membrane-disrupting polyene antibiotic, the hemolytic toxicity of PapA was negligible. At 10~25 ${\mu}g/ml$ of MIC levels for the tested strains, the hemolysis ratio of human erythrocytes was less than 5%. Our results suggest that PapA could be a therapeutic fungicidal agent having potential as a broad spectrum antimicrobial agent.

• Journal of Microbiology and Biotechnology
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• v.32 no.8
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• pp.1003-1010
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• 2022

The purpose of this study was to examine the phytochemical compounds and antibacterial activity of Coffea robusta leaf extract (RLE). The results indicated that chlorogenic acid (CGA) is a major component of RLE. The minimum inhibitory concentrations (MICs) of RLE against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Salmonella Typhimurium were 6.25, 12.5, 12.5, and 12.5 mg/ml, respectively. RLE effectively damages the bacterial cell membrane integrity, as indicated by the high amounts of proteins and nucleic acids released from the bacteria, and disrupts bacterial cell membrane potential and permeability, as revealed via fluorescence analysis. Cytotoxicity testing showed that RLE is slightly toxic toward HepG2 cells at high concentration but exhibited no toxicity toward Caco2 cells. The results from the present study suggest that RLE has excellent potential applicability as an antimicrobial in the food industry.

• IMMUNE NETWORK
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• v.13 no.3
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• pp.94-101
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• 2013

Amorphous silica particles, whose applications are increasing in many biomedical fields, are known to be less toxic than crystalline silica. In this study, the inflammatory effects of amorphous silica nanoparticles were investigated using 30-nm amorphous silica nanoparticles and human peripheral blood mononuclear cells (PBMCs) or purified monocytes. As a result, production of IL-$1{\beta}$ and IL-8 were increased. In addition, the mitochondrial reactive oxygen species (ROS) was detected, which may lead to mitochondrial membrane disruption. Most importantly, inflammasome formation was observed. Therefore, these results provide immunological information about amorphous silica nanoparticles and suggest that amorphous silica nanoparticles can evoke innate immune reactions in human monocytes through production of IL-$1{\beta}$ and IL-8.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2008.04a
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• pp.23-30
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• 2008

Mitochondria biogenesis requires a coordination of two genomes, nuclear DNA (nDNA) and mitochondrial DNA (mtDNA). Disruption of mitochondria function leads to a loss of mitochondrial membrane potential and ATP generating capacity and consequently results in chronic degenerative diseases including insulin resistance, metabolic syndrome and neurodegenerative diseases. Although PPAR-${\gamma}$ coactivator-$1{\alpha}$ (PGC-$1{\alpha}$) was discovered as a central regulator of mitochondria biogenesis and a transcriptional co-activator of nuclear respiratory factor (NRF) and mitochondrial transcription factor A (Tfam), the expressions of PGC-$1{\alpha}$, NRF and Tfam were not significantly altered in tissues showing abnormal mitochondria functions. This observation suggests that there should be another regulator(s) for mitochondria function. Here, we demonstrate microRNAs (miRNAs) can modulate mitochondria function. Overexpression of microRNA dissipated mitochondrial membrane potential and increased ROS production in vitro and in vivo. It will be discussed the target of microRNA and its role in metabolic syndrome.

• Advances in environmental research
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• v.3 no.4
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• pp.307-319
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• 2014

Four chickpea cultivars viz. kabuli (Pusa 1088 and Pusa 1053) and desi (Pusa 1103 and Pusa 547) differing in sensitivity to high temperature conditions were analyzed in earthern pot (30 cm) at different stages of growth and development in the year of 2010 and 2011. Pusa-1053 (kabuli type) showed maximum photosynthetic rate and least by Pusa-547 (desi type), whereas maximum cell membrane thermostability were recorded in Pusa-1103 and minimum in Pusa-1088. Among the treatments, the plants grown under elevated temperature conditions had produced 13.01% more significant data in comparison to plants grown under continuous natural conditions. Stomatal conductance were reduced 44.25% under elevated temperature conditions than natural conditions, whereas 35.56%, when plants grown under initially natural conditions upto 30DAS, then 30-60DAS elevated temperature and finally shifted to natural conditions till harvest. In case of Pusa-1103, stomatal conductance was maximum as compared to rest of 2.7% from Pusa-1053, 8.9% from Pusa-1088, and 10.3% in Pusa-547 throughout the study. Plants grown under continuous elevated temperature conditions had produced 15.30% and 15.32% more significant membrane thermostability index in comparison to continuous natural conditions at vegetative stage and 19.40% and 18.44% at flowering stage, while the better response was recorded at pod formation stage. Pusa-1053 had given 2.8% more membrane thermostability index than Pusa-1088 and Pusa-1103 had given 1.6% more membrane thermostability index than Pusa-547 in the present study. The membrane disruption caused by high temperature may alter water ion and inorganic solutes movement, photosynthesis and respiration. Thus, thermostability of the cell membrane depends on the degree of the electrolyte leakage.

• Bulletin of the Korean Chemical Society
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• v.31 no.2
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• pp.372-378
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• 2010

Membrane disruption by an antimicrobial peptide, protegrin-1 (PG-1), was investigated by measuring the $^2H$ solid-state nuclear magnetic resonance (SSNMR) spectra of 1-palmitoyl-$d_{31}$-2-oleoyl-sn-glycero-3-phosphatidylcholine (POPC_$d_{31}$) in the mixture of PG-1 and POPC_$d_{31}$ lipids deposited on thin cover-glass plates. The experimental line shapes of anisotropic $^2H$ SSNMR spectra measured at various peptide-to-lipid (P/L) ratios were simulated reasonably by assuming the mosaic spread of bilayers containing pore structures or the coexistence of the mosaic spread of bilayers and a fast-tumbling isotropic phase. Within a few days of incubation in the hydration chamber, the pores were formed by the peptide in the POPC_$d_{31}$ and POPC_$d_{31}$/cholesterol membranes. However, the formation of the pores was not clear in the POPC_$d_{31}$/1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylglycerol (POPG) membrane. Over a hundred days after hydration, a rapidly rotating isotropic phase increased in the POPC_$d_{31}$ and the POPC_$d_{31}$/cholesterol membranes with the higher P/L ratios, but no isotropic phase appeared in the POPC_$d_{31}$/POPG membrane. Cholesterol added in the POPC bilayer acted as a stabilizer of the pore structure and suppressed the formation of a fast-tumbling isotropic phase.

• Journal of Microbiology and Biotechnology
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• v.22 no.10
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• pp.1367-1374
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• 2012

Pleurocidin, a 25-mer antimicrobial peptide, has been known to exhibit potent antibacterial activity. To investigate the functional roles in N- and C-terminal regions of pleurocidin on the antibacterial activity, we designed four truncated analogs. The antibacterial susceptibility testing showed that pleurocidin and its analogs exerted antibacterial effect against various bacterial strains and further possessed specific activity patterns corresponding with their hydrophobic scale [pleurocidin > Anal 3 (1-22) > Anal 1 (4-25) > Anal 4 (1-19) > Anal 2 (7-25)]. Fluorescence experiments using 1,6-diphenyl-1,3,5-hexatriene (DPH) and 3,3'-dipropylthiadicarbocyanine iodide [$diSC_3(5)$] indicated that the differences in antibacterial activity of the peptides were caused by its membrane-active mechanisms including membrane disruption and depolarization. Blue shift in tryptophan fluorescence demonstrated that the decrease in net hydrophobicity attenuates the binding affinity of pleurocidin to interact with plasma membrane. Therefore, the present study suggests that hydrophobicity in the N- and C-terminal regions of pleurocidin plays a key role in its antibacterial activity.

• Biomedical Science Letters
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• v.26 no.4
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• pp.336-343
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• 2020

The present study was carried out to investigate the possibility that bispidinone derivative makes anticancer drug availability to human cervical carcinoma cell. The B8 has the lowest IC50 value among B8, B9 and B10 which are bispidinone analogue with bromide. According to cytotoxic test through WST-8 assay, B8 shows the most magnificent cytotoxicity effectiveness with 76 μM of IC50 value. In human cervical carcinoma cell treated with B8, it noticeably controlled cellular multiplication by increase of concentration and time. Furthermore, morphological changes like cellular shrink, disruption and nuclear condensation, feature of apoptosis, are observed. Annexin V-FITC/PI double staining assay test proved that B8 can cause apoptosis. Moreover, after treatment with 76 μM of B8, flow cytometry analysis shows that increase of active oxygen species are induced and membrane potential in mitochondria is decreased. Manifestation of Bcl-2 family and caspase cascades protein provides evidence that B8 induces apoptosis through mitochondria and caspase-related pathway. Taken together, we suggested that B8 reduced membrane potential in mitochondria and induce apoptosis through the pathway depended on mitochondria and caspase.

• Journal of Audiology & Otology
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• v.25 no.3
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• pp.159-162
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• 2021

Temporal bone trauma can cause hearing loss and in case of prolonged conductive hearing loss, traumatic ossicular injury should be considered. Separation of the incudostapedial joint is the most common lesion, and stapediovestibular dislocation is relatively rare but can easily cause perilymphatic fistula. Here, we report a very rare case of external stapediovestibular dislocation after trauma, ending up with successful surgical outcome. A 27-year-old man with non-progressive hearing loss on the right side since childhood visited the clinic. Audiogram showed a conductive hearing loss with air-bone gap of 55 dB on the right side. Temporal bone CT revealed the disruption of ossicular chain. An exploratory tympanotomy identified multiple ossicular disruptions including external stapediovestibular dislocation with shiny fibrous membrane sealing the oval window. Ossicular chain reconstruction was performed using the total ossicular replacement prosthesis of titanium. A postoperative audiogram showed a recovery of air-bone gap less than 10 dB. To the best of our knowledge, this is the first case of external long-standing stapediovestibular dislocation, with oval window completely sealed with fibrous membrane, ending up with successful hearing recovery by surgery. This case would help dealing with such condition which can be encountered in the clinic.