• Korean Journal of Environmental Biology
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• v.39 no.4
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• pp.452-462
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• 2021

Pretilachlor (PRE) is a common acetanilide herbicide used worldwide. However, its effects on aquatic organisms, particularly marine photosynthetic life, are not sufficiently known. Herein, we evaluated the toxic effects of PRE by physiological and molecular parameters in the photosynthetic dinoflagellate Prorocentrum minimum. The cell density, pigment content, and photosynthetic parameters (F_v/F_m and PI_ABS) were considerably decreased with increased PRE exposure time and doses. In addition, photosynthesis-related genes, PmpsbA, PmpsaA, and PmatpB, were significantly upregulated when exposed to 1.0 mg L^-1 of PRE for 24 h (p<0.001). In 72 h treatment, the relative gene expression was significantly increased (0.1 and 0.5 mg L^-1; p<0.01). In contrast, PmrbcL was decreased or little changed compared to the controls. Reactive oxygen species (ROS) increased after 24 h exposure (p<0.001). However, the transcriptional fold-changes in glutathione S-transferase (GST) were significantly increased (0.5 and 1.0 mg L^-1; p<0.001) at 72 h. These findings suggested that the PmGST might be involved in PRE detoxification in P. minimum. In addition, PRE may affect the photosystem function in phytoplankton similar to other acetanilides, causing severe damage or cell death.

• Journal of Animal Science and Technology
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• v.48 no.4
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• pp.563-574
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• 2006

This study was performed to investigate if high molecular weight(～200kDa) of chitosan can be a potential possibility to replace with the sodium nitrite in low-fat sausages. pH, proximate analysis, Hunter color values, vacuum purge, expressible moisture(EM, %), texture profile analysis(TPA), shelf-life effect were measured. No differences in physico-chemical properties were observed between controls and chitosan treatments(p>0.05). Since Hunter-a-values(redness) were reduced with the addition of chitosan as compared to the sausages containing sodium nitrite and sodium lactate, it could not be replaced by chitosan completely. However, total plate counts(TPC), thiobarbituric acid reactive substance(TBARS), volatile basis nitrogen(VBN) did not differ between chitosan treatments and controls. These results indicated that the addition of chitosan into meat products would be replaced with sodium nitrite partially, but it may not be completely replaced due to the reduced Hunter-a-values. Further research will be continuously performed to screen the natural ingredients which might have a cured pigment in meat products.

• Journal of Environmental Science International
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• v.20 no.12
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• pp.1509-1519
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• 2011

The protective effect of nitric oxide (NO) on the antioxidant system under paraquat(PQ) stress was investigated in leaves of 8-week-old lettuce (Lactuca sativa L.) plants. PQ stress caused a decrease of leaf growth including leaf length, width and weight. Application of NO donor, sodium nitroprusside (SNP), significantly alleviated PQ stress induced growth suppression. SNP permitted the survival of more green leaf tissue preventing chlorophyll content reduction and of higher quantum yield for photosystem II than in non-treated controls under PQ exposure, suggesting that NO has protective effect on chloroplast membrane in lettuce leaves. Flavonoids and anthocyanin were significantly accumulated in the leaves upon PQ exposure. However, the rapid increase of these compounds was alleviated in the SNP treated leaves. PQ treatment resulted in lipid peroxidation and induced accumulation of hydrogen peroxide ($H_2O_2$) in the leaves, while SNP prevented PQ induced increase in malondialdehyde (MDA) and $H_2O_2$. These results demonstrate that SNP serves as an antioxidant agent able to scavenge $H_2O_2$ to protect plant cells from oxidative damage. The activities of two antioxidant enzymes that scavenge reactive oxygen species, superoxide dismutase (SOD) and catalase (CAT) in lettuce leaves in the presence of NO donor under PQ stress were higher than those under PQ stress alone. Application of 2-(4-carboxyphenyl)-4, 4, 5, 5-tetramethylimidazoline-1-oxyl-3-oxide (PTIO), a specific NO scavenger, to the lettuce leaves arrested SNP mediated protective effect on leaf growth, photosynthetic pigment and antioxidant systems. However, PTIO had little effect on lettuce leaves under PQ stress compared with that of PQ stress alone. The obtained data suggest that the damage caused by PQ stress is in part due to increased generation of active oxygen by maintaining increased antioxidant enzyme activities and SNP protects plants from oxidative stress. From these results it is suggested that NO might act as a signal in activating active oxygen scavenging system that protects plants from oxidative damage induced by PQ stress and thus confer PQ tolerance.

• Food Science of Animal Resources
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• v.37 no.3
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• pp.418-428
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• 2017

In this study, the effects of pre-converted nitrite from Swiss chard powder (PS) on the color stability and shelf-life of cooked pork patties during refrigerated storage for 28 d were investigated. Nitrite was added at a concentration of approximately 120 ppm. Five treatments were formulated as follows: Control (120 ppm nitrite), T1 (2% PS), T2 (2% pre-converted nitrite from celery powder; PC), T3 (1% PS + 60 ppm nitrite), and NC (nitrite-free). The T1 and T3 samples had higher nitrosoheme pigment contents, which were associated with the redness of the samples (p<0.05). T1 resulted in the highest redness value (p<0.05). The redness and yellowness of the cooked pork patties increased with increasing PS levels. The pH of the samples subjected to all treatments decreased with progress of the storage period (p<0.05). The pH of the T1 and T3 samples treated with PS was lower (p<0.05) than that obtained with other treatments, as PS has a lower pH value. The treatments in which PS was added were most effective for reducing the level of thiobarbituric acid reactive substances (TBARS) and the residual nitrite content relative to the control. T1 resulted in the highest flavor, off-flavor, and overall acceptability scores during storage (p<0.05). The total viable bacterial count for all treatments was below 1 Log CFU/g, and E. coli and coliform bacteria were not detected during storage. Therefore, these results suggested that pre-converted nitrite from Swiss chard powder is a potential replacement for nitrite in meat products.

• Journal of Animal Science and Technology
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• v.55 no.6
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• pp.531-537
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• 2013

Vitamin E has been applied as a dietary supplement or post mortem to meat cuts to preserve meat quality and extend shelf life. This study was conducted to determine the effects of supplementation of the diet of Hanwoo steers with Economas $E^{(R)}$, a less expensive alternative to vitamin E, on meat quality preservation. To accomplish this, 36 Hanwoo steers were randomly allotted into three treatment groups ; no additive (control), Economas $E^{(R)}$(T1) and vitamin E (T2). Vitamin E and Economas $E^{(R)}$ were included in the diets at 500 mg/head and 200 mg/head, respectively, for 5 months. Evaluation of carcass performance parameters immediately after slaughter revealed no treatment effects (P>0.05). Samples collected from the loin area and stored at $4^{\circ}C$ for up to 9 days showed that T1 and T2 preserved pigment and lipid stability as indicated by significantly (P<0.05) higher CIE $L^*$ and lower CIE $a^*$ and CIE $b^*$ values and a less rapid increase in thiobarbituric acid reactive substance (TBARS) relative to the control. However, treatments had no effect (P>0.05) on cholesterol and fatty acid content in meat. Based on these findings, Economas $E^{(R)}$ provided at 200 mg/head is as effective as vitamin E applied at 500 mg/head at preserving Hanwoo meat quality over a 9 day storage period at $4^{\circ}C$.

• Food Science of Animal Resources
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• v.40 no.5
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• pp.831-843
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• 2020

This study investigated the potential for using vegetable powders as a natural replacement for sodium nitrite and their effects on the physicochemical characteristics of alternatively cured pork products. We analyzed pork products subjected to four treatments: control (0.015% sodium nitrite), Chinese cabbabe powder (CCP) treatment (0.4% Chinese cabbage powder), radish powder (RP) treatment (0.4% radish powder), and spinach powder (SP) treatment (0.4% spinach powder). Among the vegetable powders prepared in this study, SP had the highest (p<0.05) nitrate content, while CCP had the lowest (p<0.05). The cooking yields from these treatments were not significantly different from each other. However, the products with vegetable powders had higher (p<0.05) pH and thiobarbituric acid reactive substances values than the control. Pork products with vegetable powders also showed lower CIE L^⁎ values and higher CIE b^⁎ values than the nitrite-added control. RP treatment had similar (p>0.05) CIE a^⁎ values to the control, while SP treatment had the lowest (p<0.05) CIE a^⁎ values. The residual nitrite content was lower (p<0.05) in the vegetable powder added pork products than in the control, although nitrosyl hemochrome and total pigment contents in the CCP and RP treatments were similar (p>0.05) to those in the control. The control, CCP, and RP treatments showed curing efficiencies greater than 80%, indicating that CCP and RP would be promising potential replacements for sodium nitrite. The results of this study suggest that RP may be a suitable natural replacement for sodium nitrite to produce alternatively cured meat products, compared to other leafy vegetable powders.

• Journal of Ginseng Research
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• v.47 no.1
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• pp.65-73
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• 2023

Background: Age-related macular degeneration (AMD) is a significant visual disease that induces impaired vision and irreversible blindness in the elderly. However, the effects of ginseng berry extract (GBE) on the retina have not been studied. Therefore, this study aimed to investigate the protective effects of GBE on blue light (BL)-induced retinal damage and elucidate its underlying mechanisms in human retinal pigment epithelial cells (ARPE-19 cells) and Balb/c retina. Methods: To investigate the effects and underlying mechanisms of GBE on retinal damage in vitro, we performed cell viability assay, pre-and post-treatment of sample, reactive oxygen species (ROS) assay, quantitative real-time PCR (qRT-PCR), and western immunoblotting using A2E-laden ARPE-19 cells with BL exposure. In addition, Balb/c mice were irradiated with BL to induce retinal degeneration and orally administrated with GBE (50, 100, 200 mg/kg). Using the harvested retina, we performed histological analysis (thickness of retinal layers), qRT-PCR, and western immunoblotting to elucidate the effects and mechanisms of GBE against retinal damage in vivo. Results: GBE significantly inhibited BL-induced cell damage in ARPE-19 cells by activating the SIRT1/PGC-1α pathway, regulating NF-kB translocation, caspase 3 activation, PARP cleavage, expressions of apoptosis-related factors (BAX/BCL-2, LC3-II, and p62), and ROS production. Furthermore, GBE prevented BL-induced retinal degeneration by restoring the thickness of retinal layers and suppressed inflammation and apoptosis via regulation of NF-kB and SIRT1/PGC-1α pathway, cleavage of caspase 3 and PARP, and expressions of apoptosis-related factors in vivo. Conclusions: GBE could be a potential agent to prevent dry AMD and progression to wet AMD.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.69 no.1
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• pp.1-14
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• 2024

High soil salinity is the most severe threat to global rice production as it causes a significant decline in rice yield. Here, we investigated the effects of various plant extracts on rice plant stress associated with high salinity. Additionally, we examined various physiological and biochemical parameters such as growth, photosynthetic activity, chlorophyll content, and lipid peroxidation - in rice plants after treatment with selected plant extracts under salt stress conditions. Of the 11 extracts tested, four - soybean leaf, soybean stem, moringa (Moringa oleifera), and Undaria pinnatifida extracts - were found to effectively reduce salt stress. A reduction of only 3-23% in shoot fresh weight was observed in rice plants under salt stress that were treated with these extracts, compared to the 43% reduction observed in plants that were exposed to stress but not given plant extract treatments (control plants). The effectiveness varied with the concentration of the plant extracts. Water content was higher in rice plants treated with the extracts than in the control plants after 6 d of salt stress, but not after 4 d of salt stress. Although photosynthetic efficiency (Fv/Fm), electron transport rate (ETR), and the content of pigments (chlorophyll and carotenoid) varied based on the types and levels of stress and the extracts that the rice plants were treated with, generally, photosynthetic efficiency and pigment content were higher in the treated rice compared to control plants. Reactive oxygen species (ROS), such as superoxide radicals, hydrogen peroxide (H₂O₂), and malondialdehyde (MDA), increased as the duration of stress increased. ROS and MDA levels were lower in the treated rice than in the control plants. Proline and soluble sugar accumulation also increased with the duration of the stress period. However, proline and soluble sugar accumulation were lower in the treated rice than in the control plants. Generally, the values of all the parameters investigated in this study were similar, regardless of the plant extract used to treat the rice plants. Thus, the extracts found to be effective can be used to alleviate the adverse effects of stress on rice crops associated with high-salinity soils.

• Journal of Life Science
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• v.29 no.11
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• pp.1273-1280
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• 2019

Age-related macular degeneration (AMD) is one of the leading causes of blindness in the elderly population, and damage to retinal pigment epithelial (RPE) cells due to oxidative stress contributes to the development of AMD. Glycyrrhiza uralensis Fischer is one of the most widely used herbal medicines for the treatment of various diseases in Asian countries. Although recent studies indicated that treatment with G. uralensis can protect cells from oxidative stress, its mechanisms in RPE cells remain unknown. We evaluated the effect of a G. uralensis ethanol extract (GU) on $H_2O_2$-induced oxidative injury in ARPE-19 RPE cells. The GU pretreatment attenuated reactive oxygen species (ROS) generation induced by $H_2O_2$, which was associated with induced expression of nuclear factor erythroid-derived-2-like 2 (Nrf2) and heme oxygenase-1 (HO-1). GU also suppressed $H_2O_2$-induced DNA damage and mitochondrial dysfunction. The inhibitory effect of GU on $H_2O_2$-induced apoptosis was associated with the protection of caspase-3 activation. Overall, GU appeared to protect RPE cells from oxidative injury by inhibiting DNA damage and reducing apoptosis. Further studies are needed to determine the regulation of Nrf2-mediated HO-1 expression, but our results suggest the possibility of using GU to reduce the risk of AMD.

• Journal of Life Science
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• v.31 no.2
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• pp.126-136
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• 2021

Oxidative stress causes injury to and degeneration of retinal pigment epithelial (RPE) cells. It is involved in several retinal disorders and leads to vision loss. In the present study, we investigated the effect of 14 kinds of natural compounds and two kinds of synthetic compounds on oxidative stress-induced cellular damage in human PRE cell lines (ARPE-19). From among them, we selected five kinds of compounds, including auranofin, FK-509, hemistepsin A, honokiol, and spermidine, which have inhibitory effects against hydrogen peroxide (H2O2)-mediated cytotoxicity. In addition, we found that four kinds of compounds (excluding auranofin) have protective effects on H2O2-induced mitochondrial dysfunction. Furthermore, the expression of phosphorylation of histone H2AX, a sensitive marker of DNA damage, was markedly up-regulated by H2O2, whereas it was notably down-regulated by FK-506, honokiol, and spermidine treatment. Meanwhile, five kinds of candidate compounds had no effect on H2O2-induced intracellular reactive oxygen species (ROS) levels, suggesting that the five candidate compounds have protective effects on oxidative stress-induced cellular damage through the ROS-independent pathway. Taken together, according to the results of H2O2-mediated cellular damage―such as cytotoxicity, apoptosis, mitochondrial dysfunction, and DNA damage―spermidine and FK-506 are the natural and synthetic compounds with the most protective effects against oxidative stress in RPE. Although further studies on the identification of the mechanism responsible are required, the results of the present study suggest the possibility of using spermidine and FK-506 to suppress the risk of retinal disorders.