• Food Science and Preservation
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• v.15 no.5
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• pp.743-748
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• 2008

Amyloid $\beta$ peptide ($A{\beta}$) is known to increase oxidative stress in nerve cells, leading to apoptosis that is characterized by free radical formation and lipid peroxidation. Neurodegenerative diseases such as Alzheimer's disease (AD) are characterized by large deposits of $A{\beta}$ in the brain. In our study, neuronal protective effects of green tea, along with water activity (0.813), and leaf storage periods (fresh leaf, or leaf stored for up to 4 weeks) were investigated. We measured protective effects against $A{\beta}$-induced cytotoxicity in neuron-like PC12 cells. Powdered green tea was extracted with distilled water at $70^{\circ}C$ for 5 min, and this extract was freeze-dried and stored at $-20^{\circ}C$ until use. In cell viability assays using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), the fresh extract, and that obtained after 1 week of leaf storage, showed the best protective effects against $A{\beta}$-induced neurotoxicity. As oxidative stress causes membrane breakdown, the protective effect of green tea extracts was investigated using lactate dehydrogenase (LDH) and trypan blue exclusion assays. LDH release into the medium was inhibited (by 20-25%) in all tests. In addition, all green tea extracts (fresh, or stored before extraction for up to 4 weeks) showed better cell protective effects ($93.3{\pm}1.8-96.2{\pm}2.4$) than did vitamin C ($91.0{\pm}1.6$), used as a positive control. The results suggest that effectiveness of green tea extracts falls with prolonged leaf storage.

• Korean Journal of Poultry Science
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• v.46 no.3
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• pp.161-171
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• 2019

Four-week-old male Korean native chicks (KNC) were assigned to 3 groups with 6 replicates (8 birds/replicate) in each group: a basal diet (CON, 100 ppm of Zn), basal diet fortified with 50 ppm of Zn with zinc oxide (ZnO), or basal diet fortified with 50 ppm of Zn with Zn-methionine (ZnM). Immediately after a 4-week-feeding trial, 6 birds per group were used to evaluate the effects of zinc supplements on antioxidant indicators and the mRNA expression of zinc transport genes. The nitrogen components, lipid peroxidation, and total antioxidant status in blood were not influenced by Zn fortified diets. However, the ZnM group showed a significant (P<0.05) increase in uric acid levels than those in the ZnO group. In the small intestine, superoxide dismutase (SOD) and glutathione peroxidase (GPX) activities, and malondialdehyde (MDA) level were unaffected by zinc supplements. The activity of glutathione S-transferase (GST) was significantly (P<0.05) enhanced by Zn-methionine supplementation. In the liver, the activity of GST was significantly (P<0.05) increased by Zn-methionine supplement without affecting SOD, GPX, and MDA levels. With respect to the mRNA expression of zinc transport genes, the ZnM group displayed a strong tendency for increases in intestinal ZnT-1 (P=0.09) and ZnT-5 (P=0.06) levels, compared to those in the CON group. Moreover, the ZnM group showed a tendency (P=0.10) for up-regulation of hepatic metallothionein mRNA as compared with the CON group. In conclusion, the Zn-fortified diet with 50 ppm of Zn-methionine helped to improve GST activity and Zn transport gene expression in the small intestine or liver of KNC.

• Journal of Life Science
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• v.29 no.2
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• pp.173-180
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• 2019

Amyloid ${\beta}$-protein ($A{\beta}$) is the principal component of senile plaques characteristic of Alzheimer's disease (AD) and elicits a toxic effect on neurons in vitro and in vivo. Many environmental factors, including antioxidants and proteoglycans, modify $A{\beta}$ toxicity. It is worthwhile to isolate novel natural compounds that could prove therapeutic for patients with AD without causing detrimental side effects. In this study, we investigated the in vitro neuroprotective effects of the ethyl acetate fraction of methanol extract of Ophiophogon japonicas (OJEA fraction). We used an MTT reduction assay to detect protective effects of the OJEA fraction on $A{\beta}_{25-35}$-induced cytotoxicity to PC12 cells. We also used a cell-based ${\beta}$-secretase assay system to investigate the inhibitory effect of the OJEA fraction on ${\beta}$-secretase activity. In addition, we performed an in vitro lipid peroxidation assay to evaluate the protective effect of the OJEA fraction against oxidative stress induced by $A{\beta}_{25-35}$ in PC12 cells. The OJEA fraction had strong protective effects against $A{\beta}_{25-35}$-induced cytotoxicity to PC12 cells and was strongly inhibitory to ${\beta}$-secretase activity, which resulted in the attenuation of $A{\beta}$ generation. In addition, the OJEA fraction significantly decreased malondialdehyde (MDA) content, which is induced by the exposure of PC12 cells to $A{\beta}_{25-35}$. Our results suggested that the OJEA fraction contained active compounds exhibiting a neuroprotective effect on $A{\beta}$ toxicity.

• Journal of Korean Society of Forest Science
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• v.100 no.3
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• pp.408-416
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• 2011

Leaf and bulb of wild garlic (Allium victorials var. platyphyllum) from Ulleung Island and Gangneung region were extracted with water and 70% ethanol and investigated on its antioxidative activity. Total polyphenol content of Ulleung island wild garlic was higher than that of Gangneung region. Total polyphenol content in bulb was high compared to content of the leaves, and 70% ethanol extract of Ulleung Island leaf was high in 72.50 mg/g. Flavonoid content in leaf was higher than that of bulb, 70% ethanol extract of Ulleung Island leaf was high in 73.30 mg/g. Electron donating activity of 70% ethanol extract from Ulleung island and water extracts (55.13%) from Gangneung were higher than those of other extracts. Bulb extracts on electron donating activity were higher than those of the leaf extracts. SOD like activity of extracts was high in 70% ethanol extract of wild gallic leaf cultivated at Gangneung. Hydroxy radical scavenging activity of wild gallic was high in leaf extracts compared to activity of bulb extracts. Hydroxy radical scavenging activity (58.85%) of Ulleung island wild gallic leaf extracts was higher than that of the wild gallic leaves of Gangneung. Lipid peroxidation inhibitory activity was both high in water and 70% ethanol leaf extracts of Ulleung island and Gangneung region, especially, 70% ethanol extract of leaves from Ulleung island was the highest 73.33%. These results suggest that extracts from wild garlic could be used as an antioxidative functional food source.

• Korean Journal of Poultry Science
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• v.48 no.1
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• pp.31-39
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• 2021

We aimed to investigate the age-dependent development of digestive organs, intestinal enzymes, and hepatic antioxidant defense system in White Leghorn chicks aged 0, 3, 7, 14, and 21 days. Body weight (BW) did not significantly change between days 0 and 7 but significantly increased (P<0.05) after day 7. The relative liver weight (g/100 g of BW) was significantly lower at day 0 than at the other ages but markedly increased at days 3 and 7 (P<0.05). The relative pancreatic weight changed similar to the change in liver weight, with the maximum development at 7 days (P<0.05). The relative intestinal and mucosal tissue weights increased rapidly after hatching (P<0.05), with the maximum growth at 7 days. Furthermore, maltase and sucrase activities were significantly higher at day 3 than at day 0 (P<0.05). Leucine aminopeptidase activity was high at day 0 and remained constant as age increased. Superoxide dismutase and glutathione S-transferase activities in the liver were the lowest at day 0 but significantly increased after 7 days (P<0.05). Glutathione peroxidase activity increased significantly after day 14 compared with that at days 0 and 7 (P<0.05). Lipid peroxidation was not affected by age. In conclusion, the digestive organ weights and hydrolase activity of chicks increased rapidly during the first 3 or 7 days post-hatching. Hepatic antioxidant enzyme activity increased simultaneously with the increase in digestive organ weights, after 7 days.

• Journal of Life Science
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• v.33 no.11
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• pp.923-935
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• 2023

Rubus crataegifolius (RC), Ulmus macrocarpa (UM), and Gardenia jasminoides (GJ) are well-known folk medicines in Asia used to treat various gastrointestinal disturbances. The present study evaluated the gastroprotective effect of LS-RUG-com, a mixture of commercially prepared powders of RC, UM, and GJ with a ratio of 3:1:2(w/w/w) against HCl/ethanol-induced gastritis, indomethacin-induced ulcers, and esophageal reflux-induced esophageal mucosal damage and Helicobacter pylori infections. In addition, TNF-α and IL-1β expressions were also determined and measured in esophageal tissue. As to HCl/ethanol-induced gastritis, the LS-RUG-com treatment at a dose of 150 mg/kg showed a remarkable anti-gastritis effect. Regarding indomethacin-induced gastric ulcers, the LS-RUG-com treatment had a significant anti-gastric ulcer effect. Furthermore, in the gastroesophageal reflux disease (GERD) model experiment, the LS-RUG-com treatment resulted in the histological recovery of stomach damage and mucosal injuries. Furthermore, the LS-RUG-com treatment led to an increase in gastric content pH, an increase in mucus protection, and a decrease in gastric pepsin output with a significant decrease in TNF-α and IL-1β. As to the Helicobacter pylori infected animal model, LS-RUG-com had a notable inhibitory effect on Helicobacter growth. The use of RC, UM, or GJ in isolation or the LS-RUG-com treatment as whole had good effects in terms of anti-oxidation, anti-neutralization, gastric acid secretion inhibition, and anti-lipid peroxidation, which supported the use of natural products as systemic gastric protective agents. Our results suggest that the LS-RUG-com might be a significant systemic gastroprotective agent that could be utilized for the treatment and/or protection from gastric disturbances and related damage.

• Korean Journal of Poultry Science
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• v.51 no.2
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• pp.107-116
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• 2024

The study was conducted to examine age-related development of digestive organs, intestinal microvilli hydrolase, and hepatic antioxidant enzyme in Korean native chicks (KNC) aged from 0-d to 28-d of post-hatching. Body weight did not significantly increase from 0-d to 3-d-old, but after that remarkably increased from 3-d to 28-d-old (P<0.05). The relative weight (g/100 g of BW) of the proventriculus, gizzard, and liver was significantly higher at 3- and 7-d-old chicks than that of the other ages. The relative weight of the intestine, mucosal tissues, and pancreas was markedly developed at the ages of 3-, 14-, and (or) 21-d-old chicks (P<0.05). In the small intestine, the specific activities of maltase and sucrose were significantly higher at 14-d-old compared with the other ages (P<0.05). Leucine aminopeptidase activity showed a constant level from 0- to 28-d-old without significance. The specific activity of alkaline phosphatase was significantly higher at 0-d-old compared with the other ages (P<0.05). In the liver, the specific activities of superoxide dismutase, glutathione peroxidase, and glutathione S-transferase were shown to be lowest at 0-d-old, but they continued to increase as the age increased. The lipid peroxidation was significantly high at the age of 21-d (P<0.05), after that its level decreased at 28-d old. In conclusion, the KNC rapidly developed digestive organs and intestinal microvilli hydrolase activity from 3- to 14-d-old after hatching. Hepatic antioxidant enzyme activity continued to increase as the age increased after hatching, resulting in 28-d-old chicks showing the highest antioxidant enzyme activity in the KNC.

• The Korean Journal of Pharmacology
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• v.32 no.3
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• pp.407-416
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• 1996

The reactive intermediates formed during the metabolism of therapeutic agents, toxicants and carcinogens by cytochromes P450 are frequently capable of covalently binding to tissue macromolecules and causing tissue damage. It has been shown that YH439, a congener of malotilate, is effective in suppressing hepatic P450 2E1 expression. The present study was designed to further establish the mechanistic basis of YH439 protection against toxicant by assessing its effects against chemical-mediated potentiated hepatotoxicity. Retinoyl palmitate (Vit-A) pretreatment of rats for 7 days substantially enhanced carbon tetrachloride hepatotoxicity, as supported by an ${\sim}5-fold$ increase in serum alanine aminotransferase (ALT) activity, as compared to $CCl_4$ treatment alone. The elevation of ALT activity due to Vit-A was completely blocked by the treatment of $GdCl_3$ a selective inhibitor of Kupffer cell activity. Concomitant pretreatment of rats with both YH439 and Vit-A resulted in a 94% decrease in Vit-A-potentiated $CCl_4$ hepatotoxicity. YH439 was also effective against propyl sulfide-potentiated $CCl_4-induced$ hepatotoxicity. Whereas propyl sulfide (50 mg/kg, 7d) enhanced $CCl_4-induced$ hepatotoxicity by >5-fold, relative to $CCl_4$ treatment alone, concomitant treatment of animals with both propyl sulfide and YH439 at the doses of 100 and 200 mg/kg prevented propyl sulfide-potentiated $CCl_4$ hepatotoxicity by 35% and 90%, respectively. Allyl sulfide, a suppressant of hepatic P450 2E1 expression, completely blocked the propyl sulfide-enhanced hepatotoxicity, indicating that propyl sulfide potentiation of $CCl_4$ hepatotoxicity was highly associated with the expression of P450 2E1 and that YH439 blocked the propyl sulfide-enhanced hepatotoxicity through modulation of P450 2E1 levels. Propyl sulfide- and $CCl_4-induced$ stimulation of lipid peroxidation was also suppressed by YH439 in a dose-related manner, as supported by decreases in malonedialdehyde production. The role of P450 2E1 induction in the potentiation of $CCl_4$ toxicity and the effects of YH439 were further evaluated using pyridine as a P450 2E1 inducer. Pyridine pretreatment substantially enhanced the $CCl_4$ hepatotoicity by 23-fold, relative to $CCl_4$ alone. YH439, however, failed to reduce the pyridine-potentiated toxicity, suggesting that the other form(s) of cytochroms P450 inducible by pyridine, but not suppressible by YH439 treatment, may play a role in potentiating $CCl_4-induced$ hepatotoxicity. YH439 was capable of blocking cadmium chloride-induced liver toxicity in mice. These results demonstrated that YH439 efficiently blocks Vit-A-enhanced hepatotoxiciy through Kupffer cell inactivation and that the suppression of P450 2E1 expression by YH439 is highly associated with blocking of propyl sulfide-mediated hepatotoxicity.