• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.4 no.1
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• pp.51-57
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• 2000

Changes in the proline accumulation of ten-day-old seedlings of Vigna angularis in response to NaCl treatment were monitored. The proline content increased gradually both with an increase in the exposure time to salt stress and in a concentration-dependent manner. The increased proline accumulation was stronger in the shoots than in the roots. The salt stress by itself resulted in a significant inhibition of the chlorophyll content. Pre-treatment with proline before salinization lasting 48 h did not significantly affect the endogenous proline level in the roots, in contrast, a considerable increase of proline was observed in the shoots. The application of exogenous proline to the seedlings increased the endogenous proline content and improved the root and shoot growth under saline conditions. Detached leaves also exhibited an increased proline level in response to the applied NaCl, however, at a lower magnitude than in the intact seedlings. The proline alleviated the inhibitory effect of the NaCl in a concentration-dependent manner, thereby suggesting that salinity is a strong inducer of proline accumulation. In addition, abscisic acid eliminated the inhibitory effect of the salt salinity, thereby indicating a protective role on salinity stress and a regulatory role in proline synthesis. Accordingly, it would appear that proline may be involved in salt tolerance.

• Journal of Animal Science and Technology
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• v.62 no.3
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• pp.348-355
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• 2020

Cyclophosphamide, a cytotoxic anticancer agent, induces immunosuppression and has several adverse effects. N-acetylcysteine alleviates oxidative stress, liver injury, and intestinal tissue damage. The present study examined whether N-acetylcysteine modulates the adverse effects of cyclophosphamide in pigs. Miniature pigs (n = 15) were used as an experimental model to evaluate the effects of N-acetylcysteine treatment on immune reactions, liver injury, and oxidative stress after cyclophosphamide challenge. Corn-soybean meal based dietary treatments were as follows: control diet with either saline injection, cyclophosphamide injection, or 0.5% N-acetylcysteine and cyclophosphamide injection. N-acetylcysteine increased the number of immune cells and decreased TNF-α production after cyclophosphamide injection and decreased TNF-α, IFN-γ, NF-κB, and IL-8 expression and increased IL-10 expression in peripheral blood mononuclear cells. Serum levels of alanine transaminase and aspartate aminotransferase decreased, superoxide dismutase activity increased, and malondialdehyde activity decreased following N-acetylcysteine treatment after cyclophosphamide injection. N-acetylcysteine decreases immunosuppression, liver injury, and oxidative stress in cyclophosphamide-challenged miniature pigs. The present study suggests that N-acetylcysteine has therapeutic application in livestock for modulating immune reactions, liver injury, and oxidative stress.

• The Journal of Korean Medicine
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• v.24 no.3
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• pp.23-34
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• 2003

Objective : In 2001, the rate of obesity in Korea reached 30.6%. There are many therapeutic ways to reduce body weight, such as low and very low calorie diet, exercise therapy, behavior modification therapy, etc. However, in many cases the patients feel stress under obesity treatment because of starvation. This study was aimed to evaluate the anti-starvation stress effect of Coicis Semen on mice. Methods : First, the mice were divided into 6 groups : Normal (group with no starvation), Control (administrated normal saline 6 times before starting 36 hours starvation), and Samples A, B, C, and D (administrated 0.25, 0.5, 1.0, 3.0 g/kg Coicis Semen respectively 6 times before starting 36 hours starvation). Then the plasma corticosterone level and rectal temperature were measured. The norepinephrine, dopamine, DOPAC (dihydroxy-phenylacetic acid), 5-HT (5-hydroxytryptamine) and 5- HIAA (5-hydroxy-indole-acetic acid) in the hypothalamus were measured by the HPLC method. Result : I. The rectal temperature in Sample group D showed a significant difference (P<0.05) compared with the Control group. 2. The DOPAC in Sample groups A, C and D showed the significant difference (P<0.05) compared with the Control group. Conclusion : It might be recognized that Coicis Semen has an anti-starvation stress effect.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.63 no.4
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• pp.314-321
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• 2018

Durum (Triticum turgidum L. ssp. durum) is a major crop species cultivated for human consumption worldwide. In Tunisia, salt stress is one of the main problems that limit crop production. 'Mahmoudi' was selected as the most salt-sensitive out of 11 Tunisian durum cultivars. Using the salt-tolerant cultivar 'Om Rabia', resistant and susceptible cultivars were evaluated to compare genetic responses under salt stress. At the fully expanded third leaf stage, salt stress was applied by submerging the pots in 500 mM NaCl for 5 min every day for saline water irrigation in the greenhouse. The treatment was applied for 1 week and salt stress tolerance was determined by changes of growth parameters to the control condition. The salt tolerance trait index and salt tolerance index were calculated and used as selection criteria. The expression levels of TdHKT1;4, TdHKT1;5, and TdSOS1 were examined using qPCR. For further evaluation of physiological responses, salt stress (150 mM NaCl) was additionally applied for 48 h at the fully expanded third-leaf stage. Increased expression of the genes responsible for salt tolerance and proline content in tolerant durum can be used to broaden genetic diversity and provide genetic resources for the durum breeding program.

• Journal of Microbiology and Biotechnology
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• v.33 no.3
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• pp.310-318
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• 2023

Microalgae are attracting much attention as promising, eco-friendly producers of bioenergy due to their fast growth, absorption of carbon dioxide from the atmosphere, and production capacity in wastewater and salt water. However, microalgae can only accumulate large quantities of lipid in abiotic stress, which reduces productivity by decreasing cell growth. In this study, the strategy was investigated to increase cell viability and lipid production by overexpressing S-adenosylmethionine (SAM) synthetase (SAMS) in the microalga Chlamydomonas reinhardtii. SAM is a substance that plays an important role in various intracellular biochemical reactions, such as cell proliferation and stress response, and the overexpression of SAMS could allow cells to ithstand the abiotic stress and increase productivity. Compared to wild-type C. reinhardtii, recombinant cells overexpressing SAMS grew 1.56-fold faster and produced 1.51-fold more lipids in a nitrogen-depleted medium. Furthermore, under saline-stress conditions, the survival rate and lipid accumulation were 1.56 and 2.04 times higher in the SAMS-overexpressing strain, respectively. These results suggest that the overexpression of SAMS in recombinant C. reinhardtii has high potential in the industrial-scale production of biofuels and various other high-value-added materials.

• Molecules and Cells
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• v.40 no.12
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• pp.966-975
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• 2017

Excessive salt disrupts intracellular ion homeostasis and inhibits plant growth, which poses a serious threat to global food security. Plants have adapted various strategies to survive in unfavorable saline soil conditions. Here, we show that humic acid (HA) is a good soil amendment that can be used to help overcome salinity stress because it markedly reduces the adverse effects of salinity on Arabidopsis thaliana seedlings. To identify the molecular mechanisms of HA-induced salt stress tolerance in Arabidopsis, we examined possible roles of a sodium influx transporter HIGH-AFFINITY $K^+$ TRANSPORTER 1 (HKT1). Salt-induced root growth inhibition in HKT1 overexpressor transgenic plants (HKT1-OX) was rescued by application of HA, but not in wild-type and other plants. Moreover, salt-induced degradation of HKT1 protein was blocked by HA treatment. In addition, the application of HA to HKT1-OX seedlings led to increased distribution of $Na^+$ in roots up to the elongation zone and caused the reabsorption of $Na^+$ by xylem and parenchyma cells. Both the influx of the secondary messenger calcium and its cytosolic release appear to function in the destabilization of HKT1 protein under salt stress. Taken together, these results suggest that HA could be applied to the field to enhance plant growth and salt stress tolerance via post-transcriptional control of the HKT1 transporter gene under saline conditions.

• Archives of Pharmacal Research
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• v.29 no.7
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• pp.566-569
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• 2006

This study examined whether or not acute stress is linked to increases in the neurosteroid levels, which is a well-known neurotransmitters associated with stress stimuli. The ginsenoside, Rb1, was tested in order to better understand its potential effects on altering the neurosteroid levels and ultimately attenuating stress. The optimal stressed condition was checked by measuring the 5a-dihydroprogesterone (DHP) and allopregnanolone (THP) levels in the brain after immobilization stress at various times. Based on this result, an acute stress model was set up to give 30 min of immobilization stress. The DHP and THP brain levels of the stressed mice were then investigated after administering Rb1 orally (10 mg/kg). These results were compared with the neurosteroid level in the stressed mice not given Rb1. Saline was administered orally to the nonstressed mice to check the placebo effect. Acute immobilization stress induced an increase in the THP and DHP concentration in the frontal cortex and cerebellum. When Rb1 was administered orally prior to immobilization stress, the THP level in the frontal cortex and cerebellum was significantly lower than that in the stressed animals not given Rb1. On the other hand, the DHP level was lower in the cerebellum only. This suggests that the metabolism of the brain neurosteroids is linked to psychological stress, and Rb1 attenuates the stressinduced increase in neurosteroids.

• Journal of Microbiology and Biotechnology
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• v.20 no.9
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• pp.1288-1294
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• 2010

Rhizobium phaseoli strains were isolated from the mung bean (Vigna radiata L.) nodules, and the most salt tolerant and high auxin producing rhizobial isolate N20 was evaluated in the presence and absence of L-tryptophan (L-TRP) for improving the growth and yield of mung bean under saline conditions in a pot experiment. Mung bean seeds were inoculated with peat-based inoculum and NP fertilizers were applied at 30-60 kg/ha, respectively. Results revealed that imposition of salinity reduced the growth and yield of mung bean. On the contrary, the separate application of L-TRP and Rhizobium appeared to mitigate the adverse effects of salt stress. However, their combined application produced more pronounced effects and increased the plant height (28.2%), number of nodules per plant (71.4%), plant biomass (61.2%), grain yield (65.3%), and grain nitrogen concentration (22.4%) compared with untreated control. The growth promotion effect might be due to higher auxin production in the rhizosphere and improved mineral uptake that reduced the adverse effects of salinity. The results imply that supplementing Rhizobium inoculation with L-TRP could be a useful approach for improving the growth and yield of mung bean under salt stress conditions.

• The Korean Journal of Physiology and Pharmacology
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• v.11 no.3
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• pp.129-133
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• 2007

There are growing evidences suggesting a pivotal role of oxidative stress in the pathophysiology of preeclampsia. We investigated oxidative stress in the rat model of preeclampsia, and in clinical cases. Pregnant female rats were injected intraperitoneally with deoxycorticosterone acetate (DOCA) and given 0.9% saline as drinking water during their pregnancy. We assessed plasma $F_2-isoprostane(8-iso-PGF_{2{\alpha})$ and malondialdehyde (MDA) in a rat model, and the same markers in the plasma of maternal blood and fetal cord blood in pregnant women with preclampsia. Blood samples from the umbilical arteries and veins were collected separately. The concentrations of MDA were increased in the preeclampsia groups of animal and humans, compared with the control group; it was significantly increased in the umbilical artery and vein of the preeclampsia group. The concentrations of $F_2-isoprostane$ were elevated in the preeclampsia groups of animal and humans, compared with the control group, and the increase in $F_2-isoprostane$ concentration was prominent in the umbilical vein than umbilical artery of the preeclampsia group. Therefore, it appears that the placenta has an important role in the pathophysiology of preeclampsia, and the $F_2-isoprostane$ of the umbilical vein may serve as a relatively reliable marker for ischemic/hypoxic injury to the fetus during the perinatal period.

• The Korea Journal of Herbology
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• v.29 no.2
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• pp.7-13
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• 2014

Objectives : Chronic mild stress (CMS) model is currently recognized as a better animal model of depression. The purpose of this study was to investigate the antidepressant-like effects of the Nelumbo nucifera leave extract using CMS model. Methods : The antidepressant-like effects of Nelumbo nucifera leaves extract was determined by using animal models of depression. Male ICR mice were divided into four groups: saline-treated normal, without CMS; saline-treated stress control; CMS+ Imipramine(20mg/kg); CMS+Nelumbo nucifera leaves extract(200mg/kg). All mice except the normal group exposed an unpredicted sequence of chronic mild stressors for 5 weeks. The behavior of mice were detected by sucrose preference test, forced swim test and tail suspension test. Then concentration of corticosterone in serum was detected by enzyme immunoassay. Results : Nelumbo nucifera leaves extract administration by daily gavage from the 3rd week exhibited an antidepressant-like effect on CMS-induced depression in mice. Nelumbo nucifera leaves extract administration at dose of 200 mg/kg significantly increased the sucrose consumption, and decreased the immobility durations in forced swim test and tail suspension test. Furthermore the corticosterone level decreased than control group. Conclusions : Chronic mild stress can affect mouse behavior and corticosterone level and cause depression. The present experiments not only further confirm the antidepressant-like effects of Nelumbo nucifera leaves extract in the sucrose preference test, forced swimming test and tail suspension test, but also the improving effects of Nelumbo nucifera leaves extract on the depression-like symptoms in the CMS model. Nelumbo nucifera leaves extract has the antagonism on CMS and produce antidepressive effects.