• Microbiology and Biotechnology Letters
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• v.49 no.4
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• pp.519-527
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• 2021

In this study, the hemolysis of Enterococcus faecalis BMSE-HMP strains, isolated from human breast milk, was investigated, and the anti-hemolytic and antimicrobial effects on multidrug-resistant (MDR) bacteria were investigated. The enzyme activity of E. faecalis BMSE-HMP 4 strains was measured, and it was found that the activities of esterase and esterase lipase were the highest. In addition, no hemolytic reaction was observed in any of the isolates. Subsequently, the anti-hemolytic activity against MDR strains causing hemolysis was evaluated. E. faecalis BMSE-HMP002 had the highest anti-hemolytic activity against Staphylococcus aureus CCARM 3855 at 75.71 ± 10.00%. The anti-hemolytic activity against Escherichia coli DC 2 CCARM 0238 and Pseudomonas aeruginosa CCARM 0223 showed that the activity of BMSE-HMP001 was highest at 76.92 ± 2.99% and 87.93 ± 1.93%, respectively. Examination of the antimicrobial effects against the MDR bacteria Staphylococcus spp., Escherichia spp., Pseudomonas spp., Salmonella spp., Klebsiella spp., Enterobacter spp., and E. faecalis BMSE-HMP strains showed antimicrobial effects against both gram-positive and gram-negative strains. Breastfeeding delivers enterococci into the intestinal tract of newborns by lactation, and its usefulness is attracting attention as it has been reported that enterococci have a potential effect on neonatal immune development. In this study, the hemolytic and antimicrobial effects of E. faecalis BMSE-HMP strains on MDR bacteria were investigated, to confirm their potential as useful lactic acid bacteria. Additional studies on the antibiotic resistance and toxicity of the E. faecalis BMSE-HMP strains, isolated in this study, are necessary to prove it safe for use.

• Journal of Life Science
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• v.32 no.1
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• pp.1-10
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• 2022

Natural products have gained increasing attention due to their advantage of long-term safety and low toxicity for a very long time. Torreya nucifera is widespread in southern Korea and Jeju Island and its seeds are commonly used as edible food. Oriental ingredients have often been reported for their insecticidal, antioxidant and antibacterial properties, but there have not yet been any studies on their antidiabetic effect. In this study, we investigated several biological activities of T. nucifera pericarp (TNP) and seeds (TNS) extracts and proceeded to characterize the antidiabetic compounds of TNS. The initial results suggested that TNS extract at 15 and 10 ㎍/ml concentration has inhibitory effects on α-glucosidase and protein tyrosine phosphatase 1B, that is 14.5 and 4.35 times higher than TNP, respectively. Thus, the stronger antidiabetic TNS was selected for the subsequent experiments to characterize its active compounds. Ultrafiltration was used to determine the apparent molecular weight of the active compounds, showing 300 kDa or more. Finally the mixture was then partially purified using Diaion HP-20 column chromatography by eluting with 50~100% methanol. Therefore we concluded that the active compounds of TNS have potential as therapeutic agents in functional food or supplemental treatment to improve diabetic diseases.

• Korean journal of applied entomology
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• v.61 no.1
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• pp.155-163
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• 2022

The application of fungicides is indispensable to global food security, and their use has increased in recent times. Fungicides, directly or indirectly, have impacted insects, leading to genetic and molecular-level changes. Various detoxification mechanisms allow insects to eliminate reactive oxygen species (ROS) toxicity induced by agrochemicals including fungicides. In the present study, we analyzed the mRNA expression levels of detoxifying enzymes in Tenebrio molitor larvae following exposure to non-lethal doses (0.2, 2, and 20 ㎍/µL) of a fungicide captan. Transcripts of peroxidases (POXs), catalases (CATs), superoxide dismutases (SODs), and glutathione-s-transferases (GSTs) were screened from the T. molitor transcriptome database. RT-qPCR analysis showed that TmPOX5 mRNA increased significantly 24 h post-captan exposure. A similar increase was noticed for TmSOD4 mRNA 3 h post-captan exposure. Moreover, the expression of TmCAT2 mRNA increased significantly 24 h post-treatment with 2 ㎍/µL captan. TmGST1 and TmGST3 mRNA expression also increased noticeably after captan exposure. Taken together, these results suggest that TmPOX5 and TmSOD4 mRNA can be used as biomarkers or xenobiotics sensors for captan exposure in T. molitor, while other detoxifying enzymes showed differential expression.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.28 no.3
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• pp.175-182
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• 2022

Heavy metals can be intentionally or unintentionally introduced into plastic food utensils, containers, and packaging (PFUCP) as additives or contaminants, which can be ingested with food by humans. Here, seven-heavy metals (lead, cadmium, nickel, chromium, antimony, copper, and manganese) with toxicity concerns were selected, and risk assessment was done by establishing their migration from 137 PFUCP products made of 16 materials distributed in Korea. Migration of heavy metals was examined by applying 4% acetic acid as a food simulant (70℃, 30 minutes) to the PFUCP products. Inductively coupled plasma mass spectrometry (ICP-MS) was employed for the analysis of migrated heavy metals, and the reliability of quantitative results was confirmed by checking linearity, LOD, LOQ, recovery, precision, and expanded uncertainty. As a result of monitoring, heavy metals were detected at a level of non-detection to 8.76 ± 11.87 ㎍/L and most of the heavy metals investigated were only detected at trace amounts of less than 1 ㎍/L on average. However, antimony migrated from PET products was significantly higher than other groups. Risk assessment revealed that all the heavy metals investigated were safe with a margin of exposure above 311. Collectively, we demonstrated that heavy metals migrated from PFUCP products distributed in Korea appear to be within the safe range.

• Journal of Wetlands Research
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• v.24 no.2
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• pp.83-92
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• 2022

The amount of the plastic waste has been increasing according to global demand for plastic. Microplastics are the most hazardous among all plastic pollutants due to their toxicity and unknown physicochemical properties. This study investigates the optimal methodology that can be applied to sewage samples for detecting microplastics before discussing reducing microplastics in MWTPs. In this study, the effect of different pretreatment methods while detecting microplastic analysis of MWTP influent samples was investigated; the samples were collected from the J sewage treatment plant. There are many pretreatment methods but two of them are widely used: Fenton digestion and hydrogen peroxide oxidation. Although there are many pretreatment methods that can be applied to investigate microplastics, the most widely used methods for sewage treatment plant samples are Fenton digestion and H₂O₂ oxidation. For each pretreatment method, there were factors that could cause an error in the measurement. To overcome this, in the case of the Fenton digestion pretreatment, it is recommended to proceed with the analysis by filtration instead of the density separation method. In the case of the H₂O₂ oxidation method, the process of washing with distilled water after the reaction is recommended. As a result of the analysis, the concentration of microplastics was measured to be 2.75ea/L for the sample using the H₂O₂ oxidation method and 3.2ea/L for the sample using the Fenton oxidation method, and most of them were present in the form of fibers. In addition, it is difficult to guarantee the reliability of measurement results from quantitative analysis performed via microscope with eyes. A calibration curve was created for prove the reliability. A total of three calibration curves were drawn, and as a result of analysis of the calibration curves, all R² values were more than 0.9. This ensures high reliability for quantitative analysis. The qualitative analysis could determine the series of microplastics flowing into the MWTP, but could not confirm the chemical composition of each microplastic. This study can be used to confirm the chemical composition of microplastics introduced into MWTP in the future research.

• Journal of Applied Biological Chemistry
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• v.65 no.4
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• pp.349-355
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• 2022

In this study, we sought to identify a soil stabilizer that can be applied to paddy fields vulnerable to arsenic (As) pollution. To this end, we conducted a pot experiment in which we evaluated the effects of different stabilizers on the bioavailability of As in paddy soil. As candidate stabilizers, we assessed calcium superphosphate (CSP), sulfur, and steel slag, which were applied at the rates of 0.7 and 1.4, 0.1 and 0.2, and 7.0 and 14.0 Ma ha^-1, respectively. On day 67 after rice transplantation, we detected significantly lower concentrations of As in the solutions of paddy soil treated with 1.4 Ma ha^-1 CSP (96.9 ㎍ L^-1) and 0.2 Ma ha^-1 sulfur (207.2 ㎍ L^-1) compared with the As concentrations in control (314.5 ㎍ L^-1) and steel slag-treated (268.6-342.4 ㎍ L^-1) soil. Compared with the As concentrations in control brown rice (0.16 mg kg^-1), concentrations in brown rice were lowest in the pots treated with 1.4 Ma ha^-1 CSP (0.09 mg kg^-1). Furthermore, in response to CSP treatments, we detected increases in the weight of rice grains (50.0-50.4 g/pot) compared with the control (40.4 g/pot) and other treatments (26.9-48.1 g/pot), which we speculate could be attributed to the reduction in As toxicity to rice owing to a decline in soil solution As contents and the fertilization effect of the CSP treatment. Collectively, our findings indicate a high-level application of CSP (1.4 Ma ha^-1) to paddy soil has a comparatively beneficial effect in mitigating the bioavailability of As.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.49 no.1
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• pp.87-96
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• 2023

This study was conducted to discover substances that regulate skin surface acidification using human epidermal keratinocyte cell lines, and to investigate their effects on the moisturizing ability and skin barrier function of the stratum corneum. Prunella vulgaris (P. vulgaris) is an herb widely distributed in Northwest Africa and North America that has been studied for its anti-apoptotic, antioxidant, and anti-inflammatory effects. However, research on the regulation of NHE1 expression and the restoration of skin barrier function has not been conducted. Analysis of P. vulgaris revealed the presence of rosmarinic acid and caffeic acid as active ingredients, which were tested for toxicity in human epidermal keratinocyte cell lines (HaCaT), and showed no toxic effects were observed at high concentarion (100 ㎍/mL or 100 µM). It is known that sodium-hydrogen ion exchange pumps (NHE1) decrease in expression in aging skin to maintain the acidic pH of the stratum corneum, and it is hypothesized that this decrease plays an important role in the impaired restoration of skin barrier function in aging skin. P. vulgaris extract and caffeic acid increased the expression of NHE1 in keratinocytes, increased the expression of natural moisturizing factor (NMF) precursor filaggrin and ceramide synthesis enzyme serine palmitoyl transferase (SPT). In addition, P. vulgaris and caffeic acid decreased the extracellular pH of keratinocytes, indicating a direct effect on skin pH regulation. Taken together, these results suggest that P. vulgaris and caffeic acid can regulate skin pH through NHE1 modulation, and may help to restore skin barrier function by increasing NMF and ceramide synthesis. These results show the possibility that honeysuckle and caffeic acid can have a positive effect on skin health, and can be the basis for the development of new skin protection products using them.

• Analytical Science and Technology
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• v.21 no.5
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• pp.383-391
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• 2008

International Agency for Research on Cancer (IARC) has classified it as a possible carcinogen and World Health Organization (WHO) has suggested 50 ng/mL as a guideline value for 1,4-dioxane. Considering the toxicity of 1,4-dioxane and ingestion rate of drinking water, the monitoring of 1,4-dioxane in drinking water in Nakdong river is very important. We analyzed 1,4-dioxane four times per year for the 12 samples of treated water and 4 samples of raw water in Nakdong river in Korea from 2000 to 2007 and surveyed the trend of concentrations of 1,4-dioxane. As a results of analysis, 1,4-dioxane was detected from 0.24 to 240.2 ng/mL in treated water and from 0.39 to 81.9 ng/mL in raw water from 2000 to 2007. The average concentrations are 22.68 ng/mL and 19.15 ng/mL in treated water and raw water, respectively. The detected concentrations was decreased but frequency of detection was not changed since establishment of regulation in 2004. Results of comparison of 95 percentile excessive cancer risk of 1,4-dioxane in treated and raw water were each $6.63{\times}10^{-6}$, $3.17{\times}10^{-6}$ before 2004 and $2.10{\times}10^{-6}$, $1.22{\times}10^{-6}$ after 2004. Also, comparing the detected concentration and frequency for each season, these were more detected the concentration and frequency for 1,4-dioxane in treated and raw water from winter to spring.

• Journal of Digestive Cancer Research
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• v.1 no.1
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• pp.36-42
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• 2013

Background/Aims: Gemcitabine is regarded as a reference regimen for advanced pancreatic cancer and shows relatively safe toxicity profiles compared with other cytotoxic agents. However, many oncologists are appeared to be still reluctant to treat elderly pancreatic cancer patients with cytotoxic chemotherapy because of predicted low response rate and potential adverse events. Methods: All patients who were received gemcitabine based chemotherapy between 2007 and 2010 were identified and clinical, laboratory, radiographic data were retrospectively reviewed. Patients were divided into two groups based on their ages: less than 65, and equal or more than 65 years old. Gemcitabine, at a dose of 1,000 mg per square meter of body surface area, was administered by intravenously over 30 minutes weekly for 3 weeks followed by 1 week rest, alone or along with other chemotherapeutic agents including cisplatin, capecitabine and erlotinib. Results: A total of 61 patients were identified and all patients were not eligible to receive operation because of advanced stage at diagnosis. Twenty three patients (37.7%) were equal or more than 65 year of age. Mean age was 56 years old and 71 years old in each group. Laboratory data including CA 19-9 were not significantly different. More gemcitabine monotherapy was delivered (56.5% vs. 26.3%, p=0.029) and less second or third line therapy was adminis- tered (17.4% vs. 50.0%, p=0.014) in elderly group. Cholangitis occurred and stent placement were performed similarly in both groups. Conclusion: Gemcitabine based chemotherapy can be administered safely to elderly pancreatic cancer patients and comparable response rate and progression free survival can be expected as young patients.

• Korean Journal of Ecology and Environment
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• v.56 no.4
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• pp.430-439
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• 2023

UV and O₃ are materials used in the water treatment process, and many studies have been reported to remove organic matters, contaminants, and microorganisms. In this study, we were investigated effects of Chirnomidae (Chironomus flaviplumus, Chironomus riparius), which are contamination indicator species to exposure UV and O₃ for the survival rate, body color change and gene expression response. The survival rate of C. flaviplumus exposed to UV decreased to about 70% after 24 hours, and C. riparius about 50%. There was no change in the survival rate of C. flaviplumus exposed to O₃, and C. riparius decreased to 95% after 10 minutes of exposure, but there was no change during the subsequent exposure time. In addition, UV and O₃ exposure to the two species in body color faded in a time-dependent. In the HSP70 gene expression, C. riparius showed an increase in expression after UV exposure compared to the control group, and a significant difference was shown 12 hours after exposure (P<0.05). C. flaviplumus exposed to O₃ showed a relatively low expression compared to the control group, and showed a significant difference at 10 minutes and 1 hour after exposure (P<0.05). These results reported the ecotoxicological effects on Chironomidae according to UV and O₃ exposure. Therefore, the results of this study can be used as basic data to understand the effects of UV and O₃, which are disinfectants used in water treatment plants, on Chirnomidae entering plants.