• Nutrition Research and Practice
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• v.14 no.1
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• pp.3-11
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• 2020

BACKGROUND/OBJECTIVES: Oxidative stress causes cell damage and death, which contribute to the pathogenesis of neurodegenerative diseases. Urolithin A (UA), a gut microbial-derived metabolite of ellagitannins and ellagic acid, has high bioavailability and various health benefits such as antioxidant and anti-inflammatory effects. However, it is unknown whether it has protective effects against oxidative stress-induced cell death. We investigated whether UA ameliorates H₂O₂-induced neuronal cell death. MATERIALS/METHODS: We induced oxidative damage with 300 μM H₂O₂ after UA pretreatment at concentrations of 1.25, 2.5, and 5 μM in SK-N-MC cells. Cytotoxicity and cell viability were determined using the CCK-8 assay. The formation of reactive oxygen species (ROS) was measured using a 2,7-dichlorofluorescein diacetate assay. Hoechst 33342 staining was used to characterize morphological changes in apoptotic cells. The expressions of apoptosis proteins were measured using Western blotting. RESULTS: UA significantly increased cell viability and decreased intracellular ROS production in a dose-dependent manner in SK-N-MC cells. It also decreased the Bax/Bcl-2 ratio and the expressions of cytochrome c, cleaved caspase-9, cleaved caspase-3, and cleaved PARP. In addition, it suppressed the phosphorylation of the p38 mitogen-activated protein kinase (MAPK) pathway. CONCLUSIONS: UA attenuates oxidative stress-induced apoptosis via inhibiting the mitochondrial-related apoptosis pathway and modulating the p38 MAPK pathway, suggesting that it may be an effective neuroprotective agent.

• Journal of Pharmacopuncture
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• v.20 no.1
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• pp.18-22
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• 2017

Objectives: The current investigation was carried out to determine the cytotoxic and the antimicrobial activities of methanolic extracts of Plumbago zeylanica. Methods: The stems, leaves, and whole plants were air dried and extracted with methanol by using a Soxhlet extractor for 72 hours at $55-60^{\circ}C$. The antimicrobial activities were determined from the zones of inhibition, which were measured by using the agar well diffusion method, and the cytotoxicity assays were performed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay method. Results: The methanolic extracts of the stem and the leaves of Plumbago zeylanica were tested against six bacterial species and nine fungal species, and both extracts showed antimicrobial activity in a dose-dependent manner. The leaf extract of Plumbago zeylanica showed maximum antimicrobial activity against both Staphylococcus aureus sub sp aureus and Fusarium oxysporum. The stem extract was found to be more antimicrobial against the Pseudomonas aeruginosa and the Penicillium expansum species. MTT assays were used to test the cytotoxicity of the whole plant extract in the HCT-116 and the K-562 cell lines, and that extract was shown to have weak cytotoxicity in both cell lines. Conclusion: In the present study, the methanolic stem extracts of Plumbago zeylanica were found to possess remarkable antibacterial activities against many human and agricultural pathogens. The extracts were also found to possess significant antifungal activities, but the antifungal activities were less than the antibacterial activities. Finally, the extracts were found to have weak cytotoxicities in the HCT-116 and the K-562 cell lines.

• Carbon letters
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• v.8 no.3
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• pp.184-190
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• 2007

Carbon Nano Tubes could be either metallic or semi-conducting in nature, depending on their diameter. Its photocatalytic behavior has given an impetus to use it as an anti-microbial agent. More than 95% Escherichia coli and Staphylococcus aureus bacteria got killed when exposed to Carbon Nano Tubes for 30 minutes in presence of sunlight. Carbon Nano Tubes are supposed to have smooth surface on to which it accumulates positive charges when exposed to light. The surface that is non illuminated has negative charge. At the cellular level microorganisms produce negative charges on the cell membrane, Therefore damaging effect of multi walled carbon nano tubes (exposed to light) on the microorganisms is possible. In this paper, photo catalytic killing of microbes by multi walled carbon nano tubes is reported. Killing was due to damage in the cell membrane, as seen in SEM micrographs. Moreover biochemical analysis of membrane as well as total cellular proteins by SDS PAGE showed that there was denaturation of membrane proteins as well as total proteins of both the microbes studied. The killed microbes that showed a decrease in number of protein bands (i.e. due to breaking down of proteins) also showed an increase in level of free amino acids in microbes. This further confirmed that proteins got denatured or broken down into shorter units of amino acids. Increased level of free amino acids was recorded in both the microbes treated with multi walled carbon nano tubes and sunlight.

• Journal of Plant Biotechnology
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• v.47 no.1
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• pp.100-106
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• 2020

Coix lacryma-jobi (Hanjeli) is known to posses anti-microbial properties. Therefore, phytochemical compounds of C. lacryma-jobi have been studied to produce novel antimicrobial agents as treatments against antibiotic-resistant bacteria.The objective of this study was to determine the phytochemical composition and antibacterial activity of the C. lacryma-jobi oil against Escherichia coli, Staphylococcus aureus, and Bacillus subtilis. The phytochemical composition of the oil was determined via gas chromatography mass spectrophotometry (GC-MS). Moreover, agar disk and agar well diffusion were employed to screen the antibacterial activity of the oil. An agar well diffusion test was implemented to determinate MIC's (minimum inhibitory concentrations). Dodecanoic acid, tetradecanoic acid, 2,3-dihydroxypropylester, 1,3-dioctanoin, N-methoxy-N-methyl-3,4-dihydro-2H-thiopyran6-carboxamide, propanamide, 5-Amino-1-(quinolin-8-yl)-1,2,3-triazole-4-carboxamide, and pyridine were identified in the C. lacryma-jobi oil. The MIC value of the oil was 0.031 g/L and the MBC of the oil was 0.125 g/L effective in all test bacteria. Dodecanoic acid displayed inhibitory activity against gram-positive and gram-negative bacteria. Therefore, our research demonstrated C. lacryma-jobi (Hanjeli) oil exhibited antibacterial activity against E. coli, S. aureus, and B. subtilis. These research suggest that C. lacryma-jobi root oil could be used for medicinal purposes; however clinical and in vivo tests must be performed to evaluate its potential as an antibacterial agent.

• Restorative Dentistry and Endodontics
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• v.44 no.1
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• pp.8.1-8.7
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• 2019

Objectives: Irrigants are imperative in endodontic therapy for the elimination of pathogens from the infected root canal. The present study compared the antimicrobial efficacy of octenidine dihydrochloride (OCT) with chlorhexidine (CHX) and sodium hypochlorite (NaOCl) against Staphylococcus epidermidis (S. epidermidis) for root canal disinfection. Materials and Methods: The minimum inhibitory concentration (MIC) was obtained using serial dilution method. The agar diffusion method was then used to determine the zones of inhibition for each irrigant. Lastly, forty 6-mm dentin blocks were prepared from human mandibular premolars and inoculated with S. epidermidis. Samples were randomly divided into 4 groups of 10 blocks and irrigated for 3 minutes with saline (control), 2% CHX, 3% NaOCl, or 0.1% OCT. Dentin samples were then collected immediately for microbial analysis, including an analysis of colony-forming units (CFUs). Results: The MICs of each tested irrigant were 0.05% for CHX, 0.25% for NaOCl, and 0.0125% for OCT. All tested irrigants showed concentration-dependent increase in zones of inhibition, and 3% NaOCl showed the largest zone of inhibition amongst all tested irrigants (p < 0.05). There were no significant differences among the CFU measurements of 2% CHX, 3% NaOCl, and 0.1% OCT showing complete elimination of S. epidermidis in all samples. Conclusions: This study showed that OCT was comparable to or even more effective than CHX and NaOCl, demonstrating antimicrobial activity at low concentrations against S. epidermidis.

• Journal of Korean Medicine Rehabilitation
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• v.31 no.1
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• pp.47-57
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• 2021

Objectives This study was conducted to confirm the possibility of Clostridium difficile infection (CDI) treatment through natural herbal medicines. Methods After screening a total of 77 herbal medicines through the paper disc agar diffusion method, we selected the herbal medicines that showed a effectiveness compared to the positive control vancomycin. Afterwards, drugs that showed inhibitory effects compared to C. difficile without inhibition of Bifidobacterium bifidum and Lactobacillus plantarum, known as beneficial bacteria, were selected and minimal inhibitory concentration (MIC) was confirmed by applying the Broth microdilution method. Results The Coptidis Rhizoma, well known for its antimicrobial effect, was found to have antimicrobial effects on C. difficile, but also had inhibitory effects on the beneficial bacterium B. bifidum. 30% ethanol extraction Crataegi fructus, Corni fructus and Mume fructus had antimicrobial effects on C. difficile without inhibiting the beneficial bacteria B. bifidum and L. plantarum. The MIC values of 30% ethanol extraction Crataegi fructus, Corni fructus and Mume fructus were found to be 10 mg/mL, 20 mg/mL and 5 mg/mL, respectively. Conclusions Crataegi fructus, Corni fructus and Mume fructus were identified as candidate medicines for C. difficile. Further researchs will need to be done in vivo, and to find an optimal extraction method accompanied by economic evaluation.

• IMMUNE NETWORK
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• v.16 no.4
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• pp.242-248
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• 2016

Thymic atrophy is a complication that results from exposure to many environmental stressors, disease treatments, and microbial challenges. Such acute stress-associated thymic loss can have a dramatic impact on the host's ability to replenish the necessary naïve T cell output to reconstitute the peripheral T cell numbers and repertoire to respond to new antigenic challenges. We have previously reported that treatment with the orexigenic hormone ghrelin results in an increase in the number and proliferation of thymocytes after dexamethasone challenge, suggesting a role for ghrelin in restraint stress-induced thymic involution and cell apoptosis and its potential use as a thymostimulatory agent. In an effort to understand how ghrelin suppresses thymic T cell apoptosis, we have examined the various signaling pathways induced by receptor-specific ghrelin stimulation using a restraint stress mouse model. In this model, stress-induced apoptosis in thymocytes was effectively blocked by ghrelin. Western blot analysis demonstrated that ghrelin prevents the cleavage of pro-apoptotic proteins such as Bim, Caspase-3, and PARP. In addition, ghrelin stimulation activates the Akt and Mitogen-activated protein kinases (MAPK) signaling pathways in a time/dose-dependent manner. Moreover, we also revealed the involvement of the FoxO3a pathway in the phosphorylation of Akt and ERK1/2. Together, these findings suggest that ghrelin inhibits apoptosis by modulating the stress-induced apoptotic signal pathway in the restraint-induced thymic apoptosis.

• Korean journal of applied entomology
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• v.29 no.4
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• pp.244-251
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• 1990

Three viral insecticides were differently formulated with a nuclear polyhedrosis virus isolated from Spdodoptera litura by addition of feeding attractant, anti-precipitate of polyhedra, spreading agent, and UV-protectants. Sucrose was effective for attraction of larval feeding to increase the mortality and for protection of polyhedra from inactivation by sunlight when added 1% to 5% of sucrose solution to the formulations. Contents of additives to the formulations were 0.5% in polyvinyl alcohol to prohibit the precipitation of polyhedra and 0.1% in Triton X-100 to spread and wet the formulations to the plant. Inactivation of the virus under sunlight was decreased when added 800g of white carbon to 100 L of water in the white carbon formulation and 30% of molasses to the molasses's. In the formulation of white carbon and molasses mixtures, activation of the virus was increased when mixtured 500g of the former with 10% of the latter. Three formulations were persisted their pathogenicity more than 95% of mortality at 3 days p.i. Encapsulation of the polyhedral surface was more distinctively coated with the carbon and showed more effective in the residual effects of the white carbon than others, but the molasses more attractive for larval feeding.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.9
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• pp.1367-1373
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• 2007

The aim of this study was to determine the feeding value to sheep of Acacia saligna grown under temperate conditions. Pen trials were undertaken to determine the effects of feeding A. saligna, which had been grown in a Mediterranean environment, on feed intake, nitrogen balance and rumen metabolism in sheep. Sheep were given ad libitum access to A. saligna with or without supplementation with PEG 4,000 or PEG 6,000. PEG 4000 appears to be the major detannification agent used in trials involving high tannin feed despite the fact that PEG 6000 has been shown to be more effective, in vitro. For this reason it was of interest to compare the two, in vivo. Dry matter intake was greater (p<0.05) in sheep supplemented with either PEG 4,000 or PEG 6,000 compared to the control. There was no difference, however, in intake between those supplemented with either PEG 4,000 or 6,000. Although animals were not weighed throughout the trial, a loss in body condition was obvious, in particular in the control group. Intake of N was greater (p<0.05) in sheep supplemented with either PEG 4,000 or PEG 6,000 than in the control. There was no difference in N intake between those supplemented with either PEG 4,000 or PEG 6,000. There were no significant differences in either the faecal or urinary N output between any of the treatment groups and all treatment groups were in negative N balance. Neither the average nor maximum pH of ruminal fluid of the control group was different to those supplemented with PEG. The minimum pH for the control group, however, was significantly higher (p<0.05) than for either of the PEG treatments. The average and the maximum ammonia levels were lower (p<0.05) in the control group compared with those in either of the PEG treatment groups. For all dietary treatments ruminal ammonia levels were well below the threshold for maximal microbial growth. Feeding A. saligna, without PEG, had a definite defaunating effect on the rumen. For all dietary treatments ruminal ammonia levels were well below the threshold for maximal microbial growth. It was concluded that A. saligna was inadequate as the sole source of nutrients for sheep, even with the addition of PEG 4,000 or PEG 6,000. The anti-nutritional effects on the animals were largely attributed to the excessive biological activity of the phenolics in the A. saligna leaves. There is a need to determine other supplements that may be complimentary with PEG to enhance the nutritive value of A. saligna to maintain a minimum of animal maintenance.

• Korean Journal of Agricultural Science
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• v.45 no.1
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• pp.19-27
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• 2018

To study the effect of natural anti-microbial chemicals on the growth and quality of chili peppers, chitosan ($100mg/L^{-1}$), stevia ($250mg/L^{-1}$), and the mixture of both chemicals at the same concentration were sprayed after planting at 1-week interval throughout the experimental period. Plant height was measured twice after the $3^{rd}$ and $4^{th}$ applications. Plant height was numerically reduced in all chemical treatments compared to that of untreated control; however, there was no statistical difference between treatments. The fruit quality was examined at commercial maturity, and only minor differences were found in fruit color, length, and dry matter content between the treatments. Although a statistical difference was not present for soluble sugars levels, total phenolics, and capsaicin contents, yield in all chemical treatments significantly increased compared to untreated control. The effect on yield increase was greater at the late harvest season regardless of treatments. Total yield of 4 harvests was higher for the chitosan treatment than other treatments. During the experiment, the entire experimental field was waterlogged for 1 day due to sudden heavy rainfall, which resulted in the occurrence of bacterial browning disease in all treatments. The rate of disease occurrence and the degree of severity, however, were much lower in the chitosan treatment. In conclusion, the potential of chitosan as an alternative antimicrobial agent was confirmed in chili peppers in this study. Further research is required on stevia as an alternative chemical for disease control in chili peppers.