• Journal of Microbiology and Biotechnology
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• v.12 no.2
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• pp.183-188
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• 2002

The ohmic heating of foods for sterilization provides a shorter come-up time compared to conventional thermal processes. The electric fields as well as the heat generated by ohmic heating facilitate germicidal effects. In the present study, the effect of ohmic heating on the structure and permeability of the cell membrane of yeast cells, Saccharomyces cerevisae, isolated from Takju (a traditional Korean rice-beer), was investigated. The ohmic heating was found to translocate intracellular protein materials out of the cell wall, and the amount of exuded protein increased significantly as the electric field increased from 10 to 20 V/cm. As higher frequencies were applied, more materials were exuded. Compared to conventional heating, more amounts of proteins and nucleic acids were exuded when these cells were treated with ohmic heating. The molecular weights of the major exuded proteins ranged from 14 kDa to 18 kDa, as analyzed by Tricine-SDS PAGE. A TEM study also confirmed the leakage of cellular materials, thus indicating irreversible damage to the cell wall by ohmic heating. It was, therefore, concluded that the electric fields generated by ohmic heating induced electroporation, causing irreversible damage to the yeast cell wall and promoting the translocation of intracellular materials.

• Korean Journal of Medicinal Crop Science
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• v.21 no.1
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• pp.1-6
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• 2013

Buckwheat (Fagopyrum esculentum) has been known for having strong anti-oxidant, anti-mutagenic, and anti-carcinogenic activities. The free radical theory of aging, also known as the oxidative stress theory of aging, claims that cellular oxidative damage accumulated with time is a major causal factor of aging. In the present study, we investigated the effect of buckwheat extracts on resistance to oxidative stress and aging using Caenorhabditis elegans as a model system. Survival under an oxidative-stress condition induced by paraquat increased markedly following 500mg/L buckwheat extracts treatment, suggesting lower cellular oxidative damage by buckwheat extracts. A lifespan assay also revealed that treatment of buckwheat extracts significantly extended both the mean and maximum lifespan in C. elegans. Interestingly, this lifespan-extension by buckwheat extracts was not accompanied by reduced fertility. These findings suggest that buckwheat extracts can confer longevity phenotype to C. elegans through its strong anti-oxidant activity and support the aging theory which emphasizes a pivotal role of oxidative stress during aging.

• Food Science and Biotechnology
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• v.18 no.1
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• pp.167-171
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• 2009

This study examined the antioxidative activity of delphinidin, a kind of anthocyanidin from eggplant. Cellular protective potential from oxidative damage by nitric oxide (NO), superoxide anion ($O_2^-$), and peroxynitrite ($ONOO^-$) using epithelial cell line LLC-PK1 cell as well as in vitro radical scavenging effects were investigated. Delphinidin showed strong in vitro radical scavenging effects against NO, $O_2^-$, and hydroxyl radical (${\cdot}OH$) in dose-dependent manners. In addition, delphinidin increased cell viability in LLC-PK1 cells in a concentration-dependent manner when viability was reduced by $ONOO^-$-induced oxidative damage. To elucidate the protective mechanisms of delphinidin from $ONOO^-$, sodium nitroprusside (SNP), and pyrogallol were also employed to generate NO and $O_2^-$, respectively. The treatment of delphinidin recovered reductions in cell viability caused by SNP and pyrogallol, indicating that delphinidin can attenuate oxidative stress induced by NO and $O_2^-$. The present study suggests that delphinidin is a promising anti oxidative agent.

• Food Science and Biotechnology
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• v.18 no.1
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• pp.207-212
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• 2009

Celandine (Chelidonium majus, family Papaveraceae) is an herb used extensively in traditional Korean medicine. To investigate its antioxidant and antiproliferative activities, the methanolic extract of celandine was introduced. The antioxidant properties of the extract were tested using various in vitro systems, including hydroxyl radical scavenging assay, DNA damage protection assay, 1,1-diphenyll-2-2-pricylhydrazyl (DPPH) free radical scavenging activity, metal chelating activity, and reducing power assay. The extract exhibited stronger antioxidant activity ($IC_{50}=7.92{\mu}g/mL$) against hydroxyl radicals in the Fenton system than butylated hydroxyanisole ($IC_{50}=51.46{\mu}g/mL$) and $\alpha$-tocopherol ($IC_{50}=67.48{\mu}g/mL$). Likewise, damage to the plasmid pBR 322 induced by hydroxyl radicals was found to be protected by the extract at a concentration of $400{\mu}g/mL$. Cellular proliferation and the induction of apoptosis were also examined by a cellular proliferation assay, flow cytometry, and mRNA expression analysis. Taken together, the extract significantly inhibited the growth of HT-29 cells in a concentration- and time-dependent manner, and gradually increased both the proportion of apoptotic cells and the expression of caspase-3. Overall, our research suggests that celandine possesses antioxidant and antiproliferative properties.

• BMB Reports
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• v.29 no.6
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• pp.513-518
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• 1996

A soluble protein from Saccharomyces cerevisiae specifically provides protection against a thiolcontaining oxidation system but not against an oxidation system without thiol. This 25-kDa protein was thus named thiol-dependent protector protein (TPP). The role of TPP in the cellular defense against oxidative stress was investigated in Escherichia coli containing an expression vector with a yeast genomic DNA fragment that encodes TPP (strain YP) and a mutant in which the catalytically essential amino acid in the active site of TPP (Cys-47) has been replaced with alanine by site-directed mutagenesis (strain YPC47A). There was a distinct difference between these two strains in regard to viability, modulation of activities of superoxide dismutase and catalase, and the oxidative damage of DNA upon exposure to menadione. These results suggest that TPP may play a direct role in the cellular defense against oxidative stress by functioning as an antioxidant protein.

• Journal of Microbiology and Biotechnology
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• v.33 no.1
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• pp.135-141
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• 2023

Protection of skin cells from chronic infrared-A (IRA) irradiation is crucial for anti-photoaging of the skin. In this study, we investigated the protective activity of Rg3(S) and Rg3(S)-incorporated anionic soybean lecithin liposomes (Rg3/Lipo) with a size of approximately 150 nm against IRA-induced photodamage in human fibroblasts. The formulated Rg3/Lipo showed increased solubility in aqueous solution up to a concentration of 200 ㎍/ml, compared to free Rg3(S). In addition, Rg3/Lipo exhibited superior colloidal stability in aqueous solutions and biocompatibility for normal human dermal fibroblasts (NHDFs). After repeated IRA irradiation on NHDFs, elevated levels of cellular and mitochondrial reactive oxygen species (ROS) were greatly reduced by Rg3(S) and Rg3/Lipo. In addition, cells treated with Rg3/Lipo exhibited noticeably reduced apoptotic signals following IRA irradiation compared to untreated cells. Thus, considering aqueous solubility and cellular responses, Rg3/Lipo could serve as a promising infrared protector for healthy aging of skin cells.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.129.1-129.1
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• 2003

Alcohol, Helicobacter pylori, stress and NSAIDs-activated neutrophils all produce reactive oxygen species (ROS), which play an important role in gastric mucosal damage. Eupatilin is an active component of Artemisia asiatica possessing cytoprotective effect. The effect of eupatilin on the production of ROS and cellular damage in AGS and ECV304 cells were evaluated to prove the cytoprotective action against the above mentioned gastric mucosal cell damages. (omitted)

• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.2
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• pp.111-120
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• 1991

In order to investigate the cellular peroxidative damage due to heated oil intake and the preventive effect of vitamin E on it rats were fed heated corn oil with acid value of 4.02 at the level of 10 Cal% and three different levels of vitamin E that were 0, 40 and 200 mg/kg diet. Control group was fed fresh corn oil and 40mg/kg diet of vitamin E. After ech feeding period of 0, 3 and 6 weeks, liver superoxide dismutase (SOD), glutathione peroxidase (GPX) activities and microsomal content of vitamin E and lipid peroxide (LPO) were measured as well as cellular morphology was examined. SOD activities and LPO contents were higher, while GPX activities and vitamin e contents were lower in heated oil groups than control group. Electromicroscopic observation revealed the loss of inner mitochondrial membrane and cristae and irregular arrangement of nuclear membrane and chromatin in heated oil groups. As dietary vitamin e level was increased, SOD activity and LPO content were decreased, but GPX activity and vitamin E content in the liver increased and cellular peroxidative damage reduced progressively. This phenomena was more remarkable in 6 weeks of feeding than 3 weeks.

• Preventive Nutrition and Food Science
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• v.10 no.1
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• pp.46-51
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• 2005

The protective effect of Acanthopanax senticosus (AS) extract on alloxan-induced pancreatic β-cell damage was investigated in HIT T-15 cells, a Syrian hamster pancreatic β-cell line. Alloxan caused the pancreatic β-cell damage through the generation of reactive oxygen free radicals, increased DNA fragmentation, and decreased cellular NAD/sup +/ levels. The β-cell damage was significantly prevented by the pretreatment with water soluble extract of AS roots. These results suggest that the protective effect of AS extract, on alloxan-induced β-cell damage, is primarily due to the inhibition of the generation of reactive oxygen free radical species (ROS) by alloxan.

• Molecular & Cellular Toxicology
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• v.1 no.1
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• pp.32-39
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• 2005

Polycyclic aromatic hydrocarbons (PAHs) are an important class of environmentally prevalent xenobiotics that exert complex effects on the biological system and characterized as probably carcinogenic materials. Single cell gel electrophoresis assays were performed in order to evaluate DNA damage occurring in the T-and B lymphocytes, spleens (T/B-cell), bone marrow, and livers of mouse exposed to mixture of PAHs (Benzo(a)pyrene, Benzo(e)pyrene, Fluoranthene, Pyrene) at dose of 400, 800, or 1600 mg/kg body weight for 2 days. DNA damage of the cells purified from mice was increased in dose dependent manner. In the blood cells and organs, DNA damage was also discovered to vary directly with PAHs. Especially T-cells had been damaged more than B-cell. Plasma proteomes were separated by 2-dimensional electrophoresis with pH 4-7 ranges of IPG Dry strips and many proteins showed significant up-and -down expressions with the dose dependent manner. Of these, significant 4 spots were identified using matrix-assisted laser desorption/ionization-time of fight (MALDI-TOF) mass spectrometry. Identified proteins were related to energy metabolism and signal transduction.