• Journal of radiological science and technology
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• v.23 no.1
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• pp.81-89
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• 2000

In the present study, to determine whether the ascorbate protect against radiation damage and the possible relationship among the radioprotective effects and antioxidant actions, the effects of ascorbate(240 mg/kg, i.p) pretreatment of mice on the survival ratio, splenic weight, major antioxidant enzymes(SOD, catalase and glutathione peroxidase) activities, glutathione contents and lipid peroxidation in the liver were examined for 2 weeks after whole-body ${\gamma}-irradiation$(6.5 Gy). The 30-day survival ratio Increased from 10% to 47% for mice treated with ascorbate. The ascorbate decreased the extent of loss in splenic weight and stimulated recovery of splenic weight in irradiated mice(p<0.01). On the day of 14 after ${\gamma-irradiation}$, the ascorbate pretreatment produced a slight increase of antioxidant enzymes activities and significantly increased reduced glutathione(GSH) contents(P<0.05) in the liver compared with non-treated group. Pretreatment with the ascorbate significantly decreased GSSG/total GSH ratio(p<0.05) without the change of GSSG in the liver and inhibited the radiation-induced increase in the hepatic malondialdehyde levels(p<0.05). In these results, we found that its radioprotective effect by protecting antioxidant enzyme activities and glutathione contents from radiation induced a decrease, and thereby suppressing lipid peroxidation which is induced by free radicals.

• Journal of Ginseng Research
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• v.22 no.1
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• pp.1-10
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• 1998

In the present study, to determine whether the antioxidative components of Korean red ginseng protect against radiation damage and the possible relationship among the radioprotective effects and antioxidant actions, the effects of total saponin (200 mg/kg, ip) and lipophilic fraction (200 mg/kg, oral) preferment of mice on the survival ratio, major antioxidant enzymes (SOD, catalase and glutathione peroxidase) activities, glutathione levels and lipid peroxidation in the liver were exiled for 2 weeks after whole ${\gamma}$-body ${\gamma}$-irradiation (6.5 Gy). The 30-day survival ratio increased from 10% to 57% and 40% for mice treated with total saponin and lipophilic fraction, respectively. On day 14 after ${\gamma}$-irradiation, the ginseng total saponin pretreatment produced a slight increase of antioxidant enzymes activities and significantly Increased reduced glutathione (GSH) contents (p<0.05) in the liver compared with non-treated group. Pretreatment with ginseng total saponin significantly deceased GSSG/total GSH ratio (p<0.05) without change of GSSG in the liver and inhibited the radiation-induced incense in the hepatic malondialdehyde levels. (p<0.05) In these results, GSH plays an important role in the liver in several detoxifications and the reduction of lipid peroxides. Thus, it appears that total saponin of red ginseng exerts its radioprotective effect by accelerating the production of endogenous antioxidants, such as glutathione from radiation induced damages and thereby oxygen free radicals.

• Mycobiology
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• v.41 no.2
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• pp.67-72
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• 2013

Pathogenic microbes secrete various enzymes with lipolytic activities to facilitate their survival within the host. Lipolytic enzymes include extracellular lipases and phospholipases, and several lines of evidence have suggested that these enzymes contribute to the virulence of pathogenic fungi. Candida albicans and Cryptococcus neoformans are the most commonly isolated human fungal pathogens, and several biochemical and molecular approaches have identified their extracellular lipolytic enzymes. The role of lipases and phospholipases in the virulence of C. albicans has been extensively studied, and these enzymes have been shown to contribute to C. albicans morphological transition, colonization, cytotoxicity, and penetration to the host. While not much is known about the lipases in C. neoformans, the roles of phospholipases in the dissemination of fungal cells in the host and in signaling pathways have been described. Lipolytic enzymes may also influence the survival of the lipophilic cutaneous pathogenic yeast Malassezia species within the host, and an unusually high number of lipase-coding genes may complement the lipid dependency of this fungus. This review briefly describes the current understanding of the lipolytic enzymes in major human fungal pathogens, namely C. albicans, C. neoformans, and Malassezia spp.

• Preventive Nutrition and Food Science
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• v.8 no.1
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• pp.36-39
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• 2003

Many defined cell culture media were formulated over 3() years ago and may be deficient in certain micronutrients whose essentiality has only subsequently been recognised. The objective of this study was to evaluate whether alpha-minimal essential medium (MEM) supplemented with 10% foetal bovine serum contained sufficient selenium for optimal activity of the selenium containing enzymes cytosolic glutathione peroxidase (cGPx) and phospholipid hydroperoxide glutathione peroxidase (PHGPx) in cultured Chinese hamster ovary (CHO) cells. Additionally, the effect of zinc deficiency and metallothionein (MT) overexpression on cGPx and PHGPx activity was studied. The addition of 100 nM of selenous acid to the culture medium increased cGPx expression by 10-fold and PHGPx by about 2-fold in both wild-type CHO-K1 cells and CHO-K1 cells overexpressing mouse MT-1. Zinc deficiency had no significant effect on enzyme activity, but cells overexpressing mouse MT-1 had higher levels of cGPx activity. Zinc deficiency decreased cell survival but overexpression of MT-1 was partially protective, probably because its presence in quantity favoured the uptake, sequestration and cellular retention of any remaining zinc. This study demonstrates that selenium in complete alpha-MEM is insufficient for optimal cGPx and PHGPx activity and may compromise the cellular response to oxidative stress.

• Journal of fish pathology
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• v.36 no.2
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• pp.361-368
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• 2023

Juveniles of the white leg shrimp Litopenaeus vannamei (Weight 0.18±0.08 g) were exposed to nitrite-N at 0, 25, 50, 100, 200 and 400 mg/L for 72 hours, and the lethal concentration, heamolymph and genes regulation were evaluated. The lethal concentration 50 (LC₅₀) of L. vannamei exposed to nitrite-N was 141.2 mg/L at 25℃ and 33 psu. In Total protein, total cholesterol, and BUN in heamolymph temporarily increased after the start of the experiment and then stabilized, but glucose, an indicator of stress, decreased over time in the entire experimental group, and creatines, an indicator of tissue damage, decreased with nitrite concentration until the first 12 hours. The genes of immune-related showed that masquerade-like serine proteinase(Mas) increased at 50 and 400 ppm for 24 hours, and then gradually decreased depending on concentration. In the case of prophenoloxidase, it was highest at 400 ppm for 40 hours, and other genes(Ras-related nuclear protein, Masquerade-like serine proteinase, proPO-activating enzyme) showed a response for 48 hours and then gradually decreased. The results of this study indicate that exposure to nitrite can affect the survival and hematological physiology of L. vannamei.

• Journal of Microbiology and Biotechnology
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• v.18 no.9
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• pp.1518-1521
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• 2008

Bacteria sense their population density and coordinate the expression of target genes, including virulence factors in Gram-negative bacteria, by the N-acylhomoserine lactones (AHLs)-dependent quorum sensing (QS) mechanism. In contrast, several soil bacteria are able to interfere with QS by enzymatic degradation of AHLs, referred to as quorum quenching. A potent AHL-degrading enzyme, AiiA, from Bacillus thuringiensis has been reported to effectively attenuate the virulence of bacteria by quorum quenching. However, little is known about the role of AiiA in B. thuringiensis itself. In the present study, an aiiA-defective mutant was generated to investigate the role of AHA in rhizosphere competence in the root system of pepper. The aiiA mutant showed no detectable AHL￢-egrading activity and was less effective for suppression of soft-rot symptom caused by Erwinia carotovora on the potato slice. On the pepper root, the survival rate of the aiiA mutant significantly decreased over time compared with that of wild type. Interestingly, viable cell count analysis revealed that the bacterial number and composition of E. carotovora were not different between treatments of wild type and the aiiA mutant. These results provide evidence that AHA can play an important role in rhizosphere competentce of B. thuringiensis and bacterial quorum quenching to Gram-negative bacteria without changing bacterial number or composition.

• Natural Product Sciences
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• v.2 no.1
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• pp.29-36
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• 1996

This study was to evaluate the antitumor and immunopotentiation effects of Manda Enzyme (ME). Oral administration of ME (0.2ml/mouse) to tumor bearing mice significantly prolonged survival rate compared to the control group with the prolongation ratio of 40%. The inhibition ratios for the first and the second experiments were 51.8% and 26.4%, respectively. Only the spleen index was significantly increased in the MEF-treated group, but not in the control group. Gamma globulin level of the MEF-treated group was elevated when mice were injected with sarcoma-180 cells on the left groin. Activities of natural killer (NK) and lymphokineactivated killer (LAK) cells were observed by $^{51}Cr-release$ method. Activities of NK cell against YAC-1 cells were significantly increased in the MEF treated group. And LAK cell activities against P815 cells were also significantly increased in the experimental group. These observations, therefore, suggest that ME may have an anticancer effect and immunopotentiating effect in vivo.

• Biomolecules & Therapeutics
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• v.24 no.1
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• pp.33-39
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• 2016

Oxidative stress activates several intracellular signaling cascades that may have deleterious effects on neuronal cell survival. Thus, controlling oxidative stress has been suggested as an important strategy for prevention and/or treatment of neurodegenerative diseases. In this study, we found that ginsenoside Rh1 inhibited hydrogen peroxide-induced reactive oxygen species generation and subsequent cell death in rat primary astrocytes. Rh1 increased the expression of phase II antioxidant enzymes, such as heme oxygenase-1 (HO-1), NAD(P)H:quinone oxidoreductase 1, superoxide dismutase-2, and catalase, that are under the control of Nrf2/ARE signaling pathways. Further mechanistic studies showed that Rh1 increased the nuclear translocation and DNA binding of Nrf2 and c-Jun to the antioxidant response element (ARE), and increased the ARE-mediated transcription activities in rat primary astrocytes. Analysis of signaling pathways revealed that MAP kinases are important in HO-1 expression, and act by modulating ARE-mediated transcriptional activity. Therefore, the upregulation of antioxidant enzymes by Rh1 may provide preventive therapeutic potential for various neurodegenerative diseases that are associated with oxidative stress.

• Journal of fish pathology
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• v.14 no.2
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• pp.65-70
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• 2001

The purpose of this study is to find out the effects of various bis(tri-n-butyltin)oxide (TBTO) on changes of inorganic matter and enzyme activity in the hemolymph of Pacific Oyster, Crassostrea gigas. Oyster were exposed to 5, 10, 20, 50, 80and $100{\mu}g$/L of TBTO for 20 days. Survival rate of the oyster wass significantly affected by $\geq80{\mu}g$/L TBTO concentration at 10 days, while the diminution of survival was found at 20 days with a lower concentration of $\geq50{\mu}g$/L TBTO. Calcium concentration in the hemolymph increased significantly after 20 days at the TBTO concentration $20{\mu}g$/L. However no change of magnesium and inorganic phosphate in the hemolymph was showed. A significant increment of GOT activities in the hemolymph was observed after 20 days at more than $20{\mu}g$/L TBTO concentraion, without typical changes of GPT activities. These results indicate that oysters can be affected by TBTO in terms of calcium concentration and GOT activity in the hemolymph when they were exposed to the TBTO concentration $20{\mu}g$/L.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.23
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• pp.10217-10223
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• 2015

Hyperactivated ${\alpha}2$-6-sialylation on N-glycans due to overexpression of the Golgi enzyme ${\beta}$-galactoside: ${\alpha}2$-6-sialyltransferase (ST6Gal-I) often correlates with cancer progression, metastasis, and poor prognosis. This study was aimed to determine the association between ST6Gal-I expression and the risk of recurrence and survival of patients with localized clear-cell renal cell carcinoma (ccRCC) following surgery. We retrospectively enrolled 391 patients (265 in training cohort and 126 in validation cohort) with localized ccRCC underwent nephrectomy at a single center. Tissue microarrays were constructed for immunostaining of ST6Gal-I. Prognostic value and clinical outcomes were evaluated. High ST6Gal-I expression was associated with Fuhrman grade (p<0.001 and p=0.016, respectively) and the University of California Los-Angeles Integrated Staging System (UISS) score (p=0.004 and p=0.017, respectively) in both cohorts. Patients with high ST6Gal-I expression had significantly worse overall survival (OS) (p<0.001 and p<0.001, respectively) and recurrence free survival (RFS) (p<0.001 and p=0.002, respectively) than those with low expression in both cohorts. On multivariate analysis, ST6Gal-I expression remained associated with OS and RFS even after adjusting for the UISS score. Stratified analysis suggested that the association is more pronounced among patients with low and intermediate-risk disease defined by the UISS score. High ST6Gal-I expression is a potential independent adverse predictor of survival and recurrence in ccRCC patients, and the prognostic value is most prominent in those with low and intermediate-risk disease defined by the UISS score.