• Advances in Traditional Medicine
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• v.9 no.2
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• pp.192-199
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• 2009

Bioactivity-directed isolation has led to the isolation of (-)-ent-costunolide (1) as the major active compound from Hepatostolonophora paucistipula. This compound (1) was determined by spectroscopic data interpretation. This sesquiterpene lactone (1) inhibited the growth of the dermatophytic fungus Trichophyton mentagrophytes ATCC 28185, (4 mm inhibition zone at $15{\mu}g$/disc), cytotoxic activity to murine leukaemia cell lines ATCC CCL 46 P 388D1 ($IC_{50}$ 687 ng/ml, at $0.075{\mu}g$/disk), BSC monkey kidney cell lines (100% of well at $15{\mu}g$/disk) and antiviral activity to Herpes simplex virus (0.25 mg/ml, 100% of well at $7.5{\mu}g$/disk) and Polio virus (0.125 mg/ml, 100% of well at $3.75{\mu}g$/disk). These results suggest that (-)-ent-costunolide (1) has potential antimicrobial and cytotoxic agents.

• Natural Product Sciences
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• v.13 no.2
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• pp.164-168
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• 2007

To investigate natural antibiotics from plant essential oils and to evaluate their synergism with current antimicrobial drugs in inhibiting antibiotic-resistant strains of Streptococcus pneumoniae. The minimal inhibitory concentrations (MICs) of eleven plant essential oils and their main components were established for two antibiotic-susceptible and two antibiotic-resistant strains of S. pneumoniae, using broth microdilution tests. Potential synergism with oxacillin, norfloxacin, or erythromycin was evaluated using a checkerboard microtitre assay. Among the tested oils, Mentha piperita oil and its main component, menthol, exhibited the strongest inhibitory activities against all of the tested strains. The activity of antibiotics against antibiotic-resistant strains of S. pneumoniae was enhanced significantly by combination with Mentha piperita oils and its main component, menthol. In conclusion, the combination Mentha piperita essential oil or menthol with antibiotics could be used to reduce the effective dose of antibiotic and to modulate the resistance of S. pneumoniae strains.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.6
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• pp.1625-1628
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• 2006

The (-)-pimara-9 (11), 15-dien-19-oic acid, acanthoic acid was extracted from the roots of Acanthopanax koreanum using bioassay-guided isolation of a MeOH extract. Acanthoic acid was assayed against Streptococcus mutans and Staphylococcus epidermidis causing dental caries and opportunistic pathogen. The minimum inhibitory concentration (MIC) of acanthoic acid against Streptococcus mutans and Staphylococcus epidermidis was 2 and 4 ${\mu}g/mL$, respectively, which was much lower than those of other natural antimicrobial agents such as 8 ${\mu}g/mL$ of tanshinone IIA. Acanthoic acid also significantly inhibited the growth of other cariogenic bacteria such as Streptococcus sobrinus and Streptococcus sanguis, and Streptococcus grodenii in the MIC range of 4${\sim}$32 ${\mu}g/mL$. Our findings suggest that acanthoic acid could be employed as a potential antibacterial agent for preventing dental caries and skin infections.

• Toxicological Research
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• v.30 no.4
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• pp.291-296
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• 2014

Saururus chinensis has been reported to contain compounds such as lignans, alkaloids, diterpenes, flavonoids, tannins, steroids, and lipids. Fermentation is commonly used to break down certain undesirable compounds, to induce effective microbial conversion, and to improve the potential nutraceutical values. Previous studies have reported that the fermentation process could modify naturally occurring constituents, including isoflavons, saponins, phytosterols, and phenols, and could enhance biological activities, specifically antioxidant and antimicrobial properties. The probiotic strains used for fermentation exert beneficial effects and are safe. In this study, the antioxidative effects of the Bacillus subtilis fermentation of Saururus chinensis were investigated in a rat model with Triton WR-1339-induced hyperlipidemia by comparing the measured antioxidative biological parameters of fermented Saururus chinensis extract to those of nonfermented Saururus chinensis extract. Fermentation played a more excellent role than nonfermentation in ultimately protecting the body from oxidative stress in the liver of the experimental rats with Triton WR-1339-induced hyperlipidemia.

• Childhood Kidney Diseases
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• v.20 no.1
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• pp.1-5
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• 2016

Since many years, continuous low dose antibiotic prophylaxis (CAP) has been used for children at a risk for recurrent urinary tract infection (UTI), especially those with vesicoureteral reflux (VUR). The incidence of recurrent UTI has been shown to be higher in children with VUR with bladder and bowel dysfunction (BBD) than in those with VUR without BBD. Therefore, CAP has been recommended for children with BBD and VUR because of the increased risk of UTI. However, the use of CAP has become highly controversial because of bacterial resistance developed due to antibiotic over-usage. The preventive effects of probiotics have been proved in various adult urogenital infections, and the antimicrobial activities of lactobacilli against uropathogens have been demonstrated in previous in vitro studies. However, a critical assessment of their efficacy in children with UTI is lacking. The importance of the use of urogenital probiotics is that it is a natural approach that replenishes the depleted normal flora to create a better environment to fight off uropathogens. Probiotics have a great potential, particularly today with the increasing threat of antibiotic-resistant microorganisms.

• Mycobiology
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• v.46 no.4
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• pp.448-451
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• 2018

Fungal perylenequinones have photodynamic activity and are promising photosensitizers for photodynamic therapy (PDT). Here, we investigated the bactericidal and antitumor activities of phleichrome from the fungal perylenequinone family in vitro. Photodynamic bactericidal activity of phleichrome was analyzed by agar-well diffusion method under dark and illuminated conditions. The photodynamic antitumor activity of phleichrome was analyzed in MCF-7, HeLa, SW480, and HepG2 human cancer cell lines using in vitro cytotoxicity assays. Photodynamic bactericidal activities against Gram-negative and Gram-positive bacteria were species-specific. Antitumor activity against all tumor cell lines increased under the illuminated condition. Depending on the results of the analyses, Phleichrome has potential for further drug development related to its antibacterial and antitumor activities.

• Journal of Microbiology and Biotechnology
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• v.30 no.12
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• pp.1854-1861
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• 2020

Staphylococcus aureus is one of the most common microorganisms and causes foodborne diseases. In particular, biofilm-forming S. aureus is more resistant to antimicrobial agents and sanitizing treatments than planktonic cells. Therefore, this study aimed to investigate the anti-biofilm effects of cell-free supernatant (CFS) of Saccharomyces cerevisiae isolated from cucumber jangajji compared to grapefruit seed extract (GSE). CFS and GSE inhibited and degraded S. aureus biofilms. The adhesion ability, auto-aggregation, and exopolysaccharide production of CFS-treated S. aureus, compared to those of the control, were significantly decreased. Moreover, biofilm-related gene expression was altered upon CFS treatment. Scanning electron microscopy images confirmed that CFS exerted anti-biofilm effects against S. aureus. Therefore, these results suggest that S. cerevisiae CFS has anti-biofilm potential against S. aureus strains.

• Journal of Microbiology and Biotechnology
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• v.31 no.1
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• pp.1-7
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• 2021

Bacterial biofilm is a community of bacteria that are embedded and structured in a self-secreted extracellular matrix. An important clinical-related characteristic of bacterial biofilms is that they are much more resistant to antimicrobial agents than the planktonic cells (up to 1,000 times), which is one of the main causes of antibiotic resistance in clinics. Therefore, infections caused by biofilms are notoriously difficult to eradicate, such as lung infection caused by Pseudomonas aeruginosa in cystic fibrosis patients. Understanding the resistance mechanisms of biofilms will provide direct insights into how we overcome such resistance. In this review, we summarize the characteristics of biofilms and chronic infections associated with bacterial biofilms. We examine the current understanding and research progress on the major mechanisms of antibiotic resistance in biofilms, including quorum sensing. We also discuss the potential strategies that may overcome biofilm-related antibiotic resistance, focusing on targeting biofilm EPSs, blocking quorum sensing signaling, and using recombinant phages.

• Fisheries and Aquatic Sciences
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• v.26 no.1
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• pp.1-23
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• 2023

Marine bioactive substances (MBS), such as phlorotannins, collagens, peptides, sterols, and polysaccharides, are increasing attention as therapeutic agents for several diseases due to their pharmacological effects. Previous studies have demonstrated the biological activities of MBS including antibacterial, anticoagulant, antidiabetic, antimicrobial, anti-inflammatory activities. Among numerous human diseases, periodontitis is one of the high-prevalence inflammatory diseases in the world. To treat periodontitis, several surgeries (bone grafting, flap surgery, and soft tissue graft) are usually used. However, the surgery for patients with chronic periodontitis induces several side effects, including additional inflammatory responses at the operated site, chronic wound healing, and secondary surgery. Therefore, this review assessed the most recent trends in MBS using Google Scholar, PubMed, and Web of Science search engines to develop marine-derived therapeutic agents for periodontitis. Further, we summarized the current applications and therapeutic potential of MBS to serve as a reference for developing novel technologies applied to MBS against periodontitis treatment.

• Journal of the korean academy of Pediatric Dentistry
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• v.37 no.2
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• pp.168-178
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• 2010

Objective : The aim of this study was to determine the antimicrobical effect of horseradish root extracts against Enterococcus faecalis and Fusobacterium nucleatum isolated from oral cavity compared with reference strain, and compared with that of chlorhexidine. Method : Horseradish root extracts and chlorhexidine were sequentially diluted and tested against anaerobes(E. faecalis, F. nucleatum) isolated from children's oral cavity. The microbes were anaerobically incubated and the minimum inhibitory concentration(MIC) and minimum bactericidal concentration(MBC) were detected. Results :1. Horseradish root extracts showed antimicrobial effect against E. faecalis isolated strain at same or slightly higher concentration compared with MIC of reference strain. 2. $625.0\sim1,250.0{\mu}g/ml$ horseradish root extracts showed similar antimicrobial effect with chlorhexidine($7.8\sim15.6{\mu}g/ml$). 3. Horseradish root extracts showed antimicrobial effect against F. nucleatum isolated strain at same or slightly higher concentration compared with MIC of reference strain. 4. $78.1\sim312.5{\mu}g/ml$ horseradish root extracts showed similar antimicrobial effect with chlorhexidine($7.8\sim15.6{\mu}g/ml$). Conclusions : The results of this study confirm that horseradish root extracts has antimicrobial effect against anaerobes isolated from oral cavity as well as reference strain. And we found the potential of horseradish root extracts as a canal irrigant or disinfectant.