• Toxicological Research
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• v.26 no.2
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• pp.83-93
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• 2010

Since it was first observed in late 1970s that human cancers often had decreased manganese superoxide dismutase (MnSOD) protein expression and activity, extensive studies have been conducted to verify the association between MnSOD and cancer. Significance of MnSOD as a primary mitochondrial antioxidant enzyme is unquestionable; results from in vitro, in vivo and epidemiological studies are in harmony. On the contrary, studies regarding roles of MnSOD in cancer often report conflicting results. Although putative mechanisms have been proposed to explain how MnSOD regulates cellular proliferation, these mechanisms are not capitulated in epidemiological studies. This review discusses most recent epidemiological and experimental studies that examined the association between MnSOD and cancer, and describes emerging hypotheses of MnSOD as a mitochondrial redox regulatory enzyme and of how altered mitochondrial redox may affect physiology of normal as well as cancer cells.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.3
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• pp.355-362
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• 2013

This study was performed to assess the antioxidant activities and whitening effects of protopectinase enzymes and mechanical maceration from soybeans on melanin synthesis. The whitening effects of enzyme treatment and mechanical maceration were examined by an in vitro mushroom tyrosinase assay and by assessing markers in B16BL6 melanoma cells. We assessed inhibitory effects on the expression of melanogenic enzymes, including tyrosinase, tyrosinase-related protein 1 (TRP-1), and tyrosinase-related protein 2 (TRP-2) in B16BL6 cells. Inhibitory effects on free radical generation were determined by measuring DPPH and hydroxyl radical scavenging activities. In DPPH radical scavenging activity, enzyme treatment and mechanical maceration had a potent anti-oxidant activity in a dose-dependent manner and significantly inhibited tyrosinase activity in vitro and in B16BL6 melanoma cells. There was also an inhibition in the expression of tyrosinase, TRP-1, and TRP-2 in B16BL6 melanoma cells. Our results show that soybean protopectinase treatment inhibits melanogenesis, with the underlying mechanism possibly due to the inhibition of tyrosinase activity and tyrosinase, TRP-1, and TRP-2 expression. We suggest that soybean protopectinase should be contained as natural active ingredients for antioxidant and whitening cosmetics.

• Journal of Applied Biological Chemistry
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• v.65 no.4
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• pp.299-306
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• 2022

In this study, derivatives of trimethoxybenzene were investigated as inhibitors of melanogenesis. We examined the effects of methyl 3,4,5-trimethoxybenzoate (MTB), ethyl 3,4,5-trimethoxybenzoate (ETB), methyl 3,4,5-trimethoxycinnamate (MTC), and ethyl 3,4,5-trimethoxycinnamate (ETC). First, the inhibitory effects of these agents on melanin production were evaluated using α-melanocyte-stimulating hormone (α-MSH)-stimulated B16F10 melanoma cells. We found that all derivatives decreased α-MSH-induced melanin production in B16F10 melanoma cells; ETC showed a strong inhibitory effect at half of the concentration of the other derivatives. As tyrosinase is considered a key enzyme of melanogenesis, we also examined whether the derivatives inhibited tyrosinase activity. MTC and ETC reduced mushroom tyrosinase activity and expression levels of α-MSH-induced B16F10 cellular tyrosinase protein. Inhibitory effects of all derivatives on α-MSH-induced B16F10 cellular tyrosinase activity were shown in a dose-dependent manner. Additionally, the derivatives were exposed to diphenylpicrylhydrazyl free radical to examine their antioxidant characteristics. All derivatives showed considerable antioxidant activity, which was 2-fold higher than that of arbutin. In conclusion, the trimethoxybenzene derivatives, including MTB, ETB, MTC, and ETC exerted anti-melanogenic and antioxidant effects on α-MSH-stimulated melanogenesis, demonstrating their potential for use as novel hypopigmenting agents and antioxidants.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.4
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• pp.510-517
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• 2016

This study was conducted to investigate the antioxidant and hepatoprotective effects of eriodictyol compound against hydrogen peroxide-induced oxidative stress in HepG2 cells by measuring expression levels of antioxidant enzymes, liver function index enzyme activities, and inhibitory effects against reactive oxygen species (ROS) production. HepG2 cell viability was assessed using 3-(4,5-dimethyl thiazole-2-yl)-2,5-diphenyl tetrazolium bromide assay. In the concentration range of $10{\sim}50{\mu}g/mL$, eriodictyol displayed over 98% cell viability in HepG2 cells. The effects of increased gene expression on hydrogen peroxide-induced oxidative stress were analyzed by monitoring antioxidant enzyme (superoxide dismutase, SOD; catalase, CAT; glutathione peroxidase, GPx) gene expression levels using real-time PCR. Eriodictyol compound significantly increased gene expression levels of SOD, CAT, and GPx in a dose-dependent manner ($10{\sim}50{\mu}g/mL$). Hepatoprotective effects against hydrogen peroxide-induced oxidative stress were analyzed by monitoring glutamic oxaloacetic transaminase (GOT), lactate dehydrogenase (LDH), and gamma-glutamyl transferase (GGT) activities in HepG2 cell culture medium using a biochemistry analyzer. Eriodictyol compound significantly reduced GOT, LDH, and GGT activities in a dose-dependent manner in HepG2 cells. ROS level in HepG2 cells was analyzed by 2',7'-dichlorofluorescein fluorescence diacetate assay, and eriodictyol compound effectively reduced the intracellular ROS level in HepG2 cells. The results reveal that eriodictyol compound can be useful for development of effective antioxidant and hepatoprotective agents.

• International Journal of Industrial Entomology and Biomaterials
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• v.43 no.2
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• pp.45-51
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• 2021

High blood cholesterol levels and oxidized cholesterol are risk factors for cardiovascular disease, which displays high annual incidence. Although studies on sericulture products, including pupae, silk protein, and blood lymph, as hypocholesterolemic substances have been reported, insufficient research in this field has been focused on silkworm larvae. Six larval extracts (Low temperature distilled water, LW; hot temperature distilled water, HW; and 30-100% ethanol, E30-E100) were prepared, and their effects on cholesterol metabolism were examined. LW most potently reduced the risk of cholesterol-related disorders. Polyphenols were highly represented in LW, corresponding with its increased antioxidant potency. The cholesterol biosynthesis enzyme, 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase (HMGCR) was strongly inhibited by LW. Hepatocytes over-expressed LDL receptor (LDLR) after LW stimulation, promoting cholesterol elimination from plasma. LW also increased ATP binding cassette transporter 1 (ABCA1) gene expression, upregulating HDL biogenesis. In conclusion, LW exhibited strong antioxidant activity, suppressed cholesterol biosynthesis, improved LDL uptake from plasma, and upregulated HDL biosynthesis. In aggregate, these activities could reduce blood cholesterol levels and prevent cardiovascular disease.

• Journal of Microbiology and Biotechnology
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• v.22 no.11
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• pp.1557-1567
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• 2012

Glutathione reductase (GR, E.C. 1.6.4.2) is an important enzyme that reduces glutathione disulfide (GSSG) to a sulfydryl form (GSH) in the presence of an NADPH-dependent system. This is a critical antioxidant mechanism. Owing to the significance of GR, this enzyme has been examined in a number of animals, plants, and microbes. We performed a study to evaluate the molecular properties of GR (OsGR) from rice (Oryza sativa). To determine whether heterologous expression of OsGR can reduce the deleterious effects of unfavorable abiotic conditions, we constructed a transgenic Saccharomyces cerevisiae strain expressing the GR gene cloned into the yeast expression vector p426GPD. OsGR expression was confirmed by a semiquantitative reverse transcriptase polymerase chain reaction (semiquantitative RT-PCR) assay, Western-blotting, and a test for enzyme activity. OsGR expression increased the ability of the yeast cells to adapt and recover from $H_2O_2$-induced oxidative stress and various stimuli including heat shock and exposure to menadione, heavy metals (iron, zinc, copper, and cadmium), sodium dodecyl sulfate (SDS), ethanol, and sulfuric acid. However, augmented OsGR expression did not affect the yeast fermentation capacity owing to reduction of OsGR by multiple factors produced during the fermentation process. These results suggest that ectopic OsGR expression conferred acquired tolerance by improving cellular homeostasis and resistance against different stresses in the genetically modified yeast strain, but did not affect fermentation ability.

• Korean Journal of Pharmacognosy
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• v.49 no.3
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• pp.240-245
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• 2018

The fruits of Eleutherococcus sessiliflorus (Rupr. & Maxim.) S. Y. Hu (Araliaceae), as edible fruits, were traditionally used for ingredients of wine or tea in Eastern Asia. In addition to, the fruits of E. sessiliflorus were known for having antioxidant and anti-inflammatory effects. Recently, we investigated that the ethanolic extracts of E. sessiliflorus fruits (DHP1501) have effects on hypertension via vasorelaxation and decrease of blood pressure. In the present study, we investigated that the gene and protein expression levels of endothelial nitric oxide synthase (eNOS) was increased by treatment of DHP1501 in HUVECs. Moreover, we confirmed the angiotensin converting enzyme inhibitory activity of DHP1501 through in vitro tasks. Therefore, DHP1501 could be a candidate of functional food for alleviating hypertension.

• Food Science and Preservation
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• v.13 no.4
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• pp.495-500
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• 2006

In order to investigate whether antioxidant biomaterials inhibits IL-4 and/or IL-13 expression in vitro and in vivo, we carried out antioxidant assays by enzyme or cell-based assays with Helianthus annuus extract. Antioxidant assays include DPPH, FRAP, hydroxyl radical assays. Helianthus annuus extract exhibited SOD scavenging activity, and had different patterns by each solvent extracted reaction. DW extract inhibited oxidative stress by $H_2O_2$ that induced apoptosis. We measured $CD4^+$ cell and IL-/13 cytokine expression in a classical mouse animal model. The result show that Helianthus annuus extract showed strung inhibition of immune response in the lung. These result suggest that Helianthus annuus extract can reduce inflammation induced by n mouse asthma model.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.11
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• pp.1293-1299
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• 2017

Obesity contributes to the development of diseases, such as type II diabetes, hypertension, coronary heart disease, and cancer. In addition, oxidative stress caused by reactive oxygen species (ROS) is recognized widely as a contributing factor in the development of chronic diseases. This study was examined the antioxidant and anti-adipogenic activities of epigallocatechin-3-gallate (EGCG) in 3T3-L1 preadipocytes. 3T3-L1 cells were differentiated with or without EGCG for 6 days. The production of glutathione (GSH) and the activities of the antioxidant enzymes, such as glutathione reductase (GR), glutathione peroxidase (GPx), catalase (CAT), and superoxide dismutase (SOD) were measured. EGCG inhibited significantly the lipid accumulation and the expression of adipogenic specific proteins including CCAAT/enhancer binding protein ${\alpha}$ and adipocyte fatty acid binding protein. The production of intracellular ROS was decreased significantly by EGCG in 3T3-L1 cells. EGCG increased the GSH production and the activities of GPx, GR, CAT, and SOD. Moreover, EGCG increased the protein expression of glutamate-cysteine ligase and heme oxygenase-1 in 3T3-L1 cells. These results suggest that EGCG increased the activity and expression of antioxidant enzymes and suppressed the lipid accumulation in 3T3-L1 cells. Therefore, the use of phytochemicals that can maintain the GSH redox balance in adipose tissue could be promising for reducing obesity.

• Toxicological Research
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• v.30 no.4
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• pp.283-289
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• 2014

Tea flavonoids and polyphenols are well known for their extraordinary antioxidant activity which is considered important for anti-aging processes in animals. This study evaluated the anti-wrinkle effects of three different kinds of tea (Camellia sinensis) water extracts (CSWEs) including green, white, and black teas using a photoaged hairless mouse model. Data showed that the CSWE-treatment greatly improved skin conditions of mice suffering from UVB-induced photoaging, based on the parameters including the skin erythema index, moisture capacity, and transepidermal water loss. In addition, the wrinkle measurement and image analysis of skin replicas indicated that CSWEs remarkably inhibited wrinkle formation. In histological examination, the CSWE-treated mice exhibited diminished epidermal thickness and increased collagen and elastic fiber content, key signatures for skin restoration. Furthermore, the reduced expression of MMP-3, a collagen-degradative enzyme, was observed in the skin of CSWE-treated animals. Interestingly, comparative data between green, white, and black tea indicated that the anti-wrinkle activity of white tea and black tea is equally greater than that of green tea. Taken together, these data clearly demonstrated that CSWEs could be used as an effective anti-wrinkle agent in photoaged animal skin, implying their extended uses in therapeutics.