• Preventive Nutrition and Food Science
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• v.8 no.2
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• pp.130-136
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• 2003

The protective effects of onion extract (OE), onion powder extracted in ethanol for 2 days. on carbon tetrachloride ($CCl_4$)-induced hepatotoxicities and the possible mechanisms involved in this protection were investigated in mice. Pretreatment with OE prior to the administration of $CCl_4$ significantly reduced the increase in serum alanine and aspartate aminotransferase activities and hepatic lipid peroxidation in a dose-dependent manner. In addition, pretreatment with OE significantly prevented the depletion of reduced glutathione content in the liver of $CCl_4$-intoxicated mice. $CCl_4$-induced hepatotoxicity was also prevented, as indicated by a liver histopathologic findings. The effects of OE on the cytochrome P450 (P450) 2E1, the major isozyme involved in $CCl_4$ biotransformation were investigated. Treatment of mice with OE resulted in a significant decrease in P450 2E1-dependent p-nitrophenol and aniline hydroxylation in a dose-dependent manner. Consistent with these observations, the P450 2E1 expressions were also decreased, as determined by immunoblot analysis. OE also exhibited antioxidant effects in FeCl$_2$-ascorbate induced lipid peroxidation in rat liver homogenates and in superoxide radical scavenging activity. These results show that the protective effects of OE against the $CCl_4$-induced hepatotoxicity may be due to its ability to block bioactivation of $CCl_4$, mainly tty inhibiting the expression and activities of P450 2E1 and by scavenging free radicals.

• The Journal of Natural Sciences
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• v.14 no.2
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• pp.67-82
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• 2004

A thiol-specific antioxidant protein (TSA or TPx) was purified from Halophilic archeabacteria Halococcus agglomeratus, by DEAE-Cellulose, Phnyl, sepharose, Sephadex G-75, Sephacryl S-100, Sephacryl S-200, and Q-Wepharose FF. This protein exhibited the preventeive effect against the inactivation of glutamine synthehase (GS) activity was support by a thiol-reducing equicalent such as dithiothreitol. TPx activity was maximal at NaCl concentration above 500mM. The molecular mass of the protein was determinated to be 22-kDa by SDS-PAGE. The TPx purified from Halococcus agglomeratus seems to be similar to other TPx family, except for the salt requirement for the maximal antioxidant activity.

• Korean Journal of Plant Resources
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• v.25 no.3
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• pp.349-356
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• 2012

The antioxidant potential and enzyme activities in Salicornia herbacea, Corylopsis coreana, Erythronium japonicum, Phragmites communis, Momordica Charantia, Nelumbo nucifera, Salvia plebeia, Portulaca oleracea, Ficus carica, Citrus junos and Cornus officinalis were determined. Their antioxidant activities were measured using DPPH radical scavenging and nitrite scavenging activity. Enzyme activities in investigated plants were evaluated as superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), and ascorbate peroxidase (APX). The DPPH scavenging rate from 100 to 2500 $mgL^{-1}$ was the highest in the flower of Corylopsis coreana. However, it was not detected in most of the samples at concentration below 100 $mgL^{-1}$. The nitrite scavenging activity according to each kind of resource plants was significantly higher in the stem of Corylopsis coreana and leaf of Nelumbo nucifera. The root extract of Erythronium japonicum had the highest SOD enzyme activity of 94.0% while leaf of Salvia plebeia showed the lowest SOD enzyme activity of 30.4%. The activity of CAT and APX showed higher values in the stem of Corylopsis coreana, root of Erythronium japonicum and root of Phragmites communis in comparison with other plants. The activity of POD showed significantly high values in stem of Corylopsis coreana, Momordica Charantia and pericarp of Citrus junos extracts. The antioxidant enzyme activities differ significantly in different plants. In conclusion, we showed that Corylopsis coreana, Erythronium japonicum Cornus officinalis, and Momordica Charantia had the potent biological activities. Therefore, these plant resources showing antioxidant activity could be good materials for development of source of functional healthy food.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2002.08a
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• pp.64-71
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• 2002

Rice(Oryza stiva L.) is a major cereal food providing nourishment to over half of the world's populations and was considered only as a source of energy. However, The recent many researches have been made to suggest that rice may relate to prevention chronic disease and health-promoting properties such as postprandial glucose response, hypocholesterolemic effect and blood pressure-lowering effect. There has been numerous observation supporting that rice has hypocholesterolemic effect. Rice, rice bran, rice bran oil and unsaponifiable matter of rice bran oil reduced plasma cholesterol in rat, hamster as well as human. Components of rice showing hypocholesterolemic effect include dietary fiber(hemicellulose, phytic acid). protein, ${\gamma}$-oryzanol, $\beta$-sitosterol, and tocotrienols. Crapo et al has been studied that the effect of various of starchy foods on the postprandial blood glucose and insulin responses in healthy and diabetic humans. The results showed that rice had lower blood glucose and insulin responses compared to potato, bread and dextrose. The different physical forms in the same starch also produce the different postprandial glucose and insulin responses. In recent years, several studies have shown that some components of rice have potent antioxidant activity against Fe$^{2+}$ -ascorbate induced lipid peroxidation in rat liver microsomal membranes. Cell culture and animal studies have shown that some components of rice have inhibitory effect on the growth and proliferation of several types of human cancer cell. It was also reported that the methanol extract of brown rice has antimutagenic activity against various mutagens. In addition, the pepsine hydrolysate from rice protein is reported to inhibit angiotensin converting enzyme activity. GABA (${\gamma}$ - aminobutyric acid) and GABA enriched rice germ is also effective for lowering blood pressure and triglyceride levels.s.

• Korean Journal of Acupuncture
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• v.17 no.1
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• pp.179-190
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• 2000

This study was undertaken to determine whether Juglandis semen extract solution (JLS solution) exerts protective effect against oxidant-induced inhibition of glutamate uptake by synaptosomes. Synaptosome was prepared from rabbit brain cortex. Glutamate uptake increased by incubation time during 10 minutes, which was significantly inhibited by 1mM t-buthylhydroperoxide(t-BHP). JLS solution prevented t-BHP-induced inhibition of glutamate uptake in a dose-dependent manner. t-BHP reduced glutamate uptake in dose-dependent fashion, which was significantly prevented by 2% JLS solution. t-BHP(1mM) and $ascorbate/Fe^{2+}(50/1{\mu}M)$ increased lipid peroxidation in synaptosomes by 5-fold, and it was significantly prevented by 2% JLS solution. $HgCl_2(0.1mM)$ inhibited glutamate uptake and increased lipid peroxidation. These changes were prevented by 2% JLS solution. Synaptosomal Na-K-ATPase activity was inhibited by t-BHP(1mM) and $H_2O_2(50mM)$, which was prevented by 2% JLS solution. The results indicate that JLS solution prevents oxidant-induced inhibition of glutamate by synaptosomes, and this may result from inhibition of lipid peroxidation induced by oxidants.

• Preventive Nutrition and Food Science
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• v.3 no.1
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• pp.1-9
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• 1998

Studies were performed to 1) investigate if ferric iron bound in complex with iron-solubilizing meat components is absorbable, 2) compare the relative iron-solubilizing capaicty of meats, and 3) investigate the physicochemical and compositional characteristics if meat meat has iron-solubilizing components . Iron-solubilizing components of beef were isolate from pH 2 HCL homogenates into dialysis bags(MWCO of 6-8K). Radiolabelled iron complexes were then generated using ferric iron and the isolated low-molecular-weight components(ILC) from undigested beef or ascrobate. The bioavailabilities of radioiron in these complexes or as ferric iron were measured as radioiron absorption into the blood one hour after injection into ligated duodenal lops of rats. Iron absorptions were ferrous -ascorbate complexes(18.8$\pm$2.2%)> ferric-ILC complexes(4.9$\pm$0.6%)>ferric iron (23.2$\pm$0.3%)(p<0.05). ILC from 0.1g of beef, pork, chicken, fish , or egg white were added to 400$\mu$g ferric iron in pH 2 HCL, the pH raised to 7,2, and soluble iron determined in the supernatant after centrifugation at 2,500g for 10 min. Iron solubilizing capabilities of ILC were pork (99.9$\pm$0.1%)>beef(93.6$\pm$3.5%)> chicken (75.8$\pm$1.8%) > fish(64.6%$\pm$3.6%)>egg white(50.9$\pm$0.9%)(p<0.05). The compositional and physico-chemical characteristics of the ILC from the above dietary protein sources were investigated.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.5
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• pp.529-534
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• 2009

Physiological activities of mistletoe extracts were examined. Total polyphenol contents, electro-donating ability, SOD-like activity, nitrite-scavenging ability and tyrosinase of mistletoe extracted with water, 50%, and 100% ethanol were determined. Total polyphenol contents of powder extracts were higher than slice extracts. EDAs showed over 90% at powder extracts. Especially mistletoe extracts with 50% ethanol were higher than water extracts. SOD-like activities of water, 50% and 100% ethanol extracts of all samples were $23.71{\sim}33.4%$ lower than those of 1.0% and 0.1% L-ascorbate solutions. Nitrite-scavenging activities at pH 1.2 were the most effective in water, 50% and 100% ethanol extracts. The results will be useful for understanding the physiolosical activities of mistletoe extracts.

• Restorative Dentistry and Endodontics
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• v.42 no.3
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• pp.188-199
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• 2017

Objectives: This in vitro study evaluated the effect of dentin biomodifiers on the immediate and long-term bond strengths of a simplified etch and rinse adhesive to dentin. Materials and Methods: Flat coronal dentin surfaces were prepared in 120 extracted human molars. Teeth were randomly divided into 5 groups (n = 24) according to 5 different surface pre-treatments: No pre-treatment (control); 1M carbodiimide (EDC); 0.1% epigallocatechin-3-gallate (EGCG); 2% minocycline (MI); 10% sodium ascorbate (SA). After surface pre-treatment, adhesive (Adper Single Bond 2 [SB], 3M ESPE) was applied. Composite was applied into transparent plastic tubes (2.5 mm in diameter), which was placed over the bonded dentin surface. From each group, 10 samples were subjected to shear bond strength (SBS) evaluation at 24 hours (immediate) and remaining 10 samples were tested after 6 months (delayed). Additionally, 4 samples per group were subjected to scanning electron microscopic analysis for observation of resin-dentin interface. The data were statistically analysed with Shaperio-Wilk W test, 2-way analysis of variance (ANOVA), and post hoc Tukey's test. Results: At 24 hours, SBS of all surface pre-treatment groups were comparable with the control group, with significant differences found between EDC and SA groups only (p = 0.009). After 6 months storage, EDC, EGCG, and MI pre-treatments preserved the resindentin bond strength with no significant fall. Conclusions: Dentin pre-treatment with all the dentin biomodifiers except SA resulted in significant preservation of resin-dentin bond over 6 months storage period, without negatively affecting the immediate bond strength of the etch and rinse adhesive tested.

• International Journal of Industrial Entomology and Biomaterials
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• v.12 no.1
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• pp.21-28
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• 2006

Peroxidase activity was measured in brown leaf spot pathogen (Myrothecium roridum) inoculated potted mulberry (Morus alba) during pre-symptomatic to various symptom development stages and compared with corresponding healthy leaf tissues. The enzyme showed a pH optimum of 7.0 and the activity was linearly increased up to 15 min of incubation. The peroxidase had a broad substrate specificity and the rates of oxidation were in the rank of pyrogallol> guaiacol> ascorbate at pH 7.0. Catechol at 10 mM inhibited 89% of guaiacol-peroxidase and 76% pyrogallol-peroxidase activities, indicated higher non-specific peroxidation in pyrogallol dependent assay system in mulberry than guaiacol. The optimum requirement for the guaiacol dependent assay was 0.2 ml (${\approx}40-60{\mu}g$ equivalent of protein) of crude enzyme source. Excepting the 8th leaf from the apex, the peroxidase activity did not vary appreciably in different leaf positions. In pre-symptomatic phases, an initial (1 to 5 min) rise of peroxidase activity was noticed in inoculated leaves, and then maintained a plateau up to 300 min. In contrary, non-infected tissue showed a slightly increased trend of enzyme level up to 420 min. In infected tissue, a sharp transient increase (3.1 fold) of peroxidase activity appeared between 300 - 420 min post infections. Afterwards, significantly different but steady maintenance of enzyme levels were observed in two treatments. On the other hand, during symptom development, a sharp increase in peroxidase activity was noticed up to 4th grade of lesion appearance (25.1 % to 50% of leaf area infection), and then declined slightly. However, in non-infected but same age healthy leaves, such huge fluctuations of enzyme level did not apparent. A high positive correlation $(R^2=0.92)$ between peroxidase activity and leaf spot development grades was also marked. The result implies that pre-symptomatic burst (between 1 - 5 and 300 - 420 min) and subsequent increased trend of guaiacol peroxidase activity may require for the symptomatic manifestation of Myrothecium leaf spot in mulberry.

• Journal of Plant Biotechnology
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• v.37 no.4
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• pp.529-538
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• 2010

Proline accumulates in plants under environmental stresses including saline stress and alkaline stress. Here, we investigated the responses to two different stresses, saline stress (200 mM NaCl) and alkaline stress (100 mM $Na_2CO_3$) in two Leymus chinensis (Trin.) genotypes, LcWT07 and LcJS0107, and effects of exogenous proline on the activities of antioxidant enzymes. Both saline stress and alkaline stress significantly induced the accumulation of proline in leaves of the two genotypes after 96 h, and alkaline stress caused a transient and significant increase in LcJS0107 plants at 6 h. A reduction in the activities of catalase (CAT, EC 1.11.1.6) and ascorbate peroxidase (APX, EC 1.11.1.11), but not in the activity of superoxide dismutase (SOD, EC 1.15.1.1), was detected in plants exposed to saline and alkaline stresses. Remarkable decrease in relative water contents (RWC) was found in 144 h stressed plants. However, lipid peroxidation estimated by malonyldialdehyde (MDA) content in leaves remained relatively stable. With the addition of exogenous proline, it did not cause changes of proline levels in two genotypes, but combined with saline or alkaline stress, the exogenous application of proline significantly induced proline accumulation after even short treatment periods. Combined with salt stress, the exogenous application also increased the activities of CAT and APX. These results indicated that exogenous proline not only increases proline levels in vivo as a osmotic adjustment under stress, but mitigates the detrimental effects of saline and alkaline stresses by increasing the activities of antioxidant enzymes.