• 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 English Language & Literature
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• v.55 no.1
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• pp.61-82
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• 2009

This paper aims to reexamine the issue of racism in Conrad's Heart of Darkness, especially in the light of Chinua Achebe's critique of the novella as a racist text entrenched with European prejudices of Africa and its people in his 1975 speech at the University of Massachusetts titled "An Image of Africa." While the novella's indictment of imperial exploitation has been noted from an early stage of its critical reception, its racism had hardly been discussed until Chinua Achebe posed it. Achebe offers the canonized status of the text as a modernist classic, "the most commonly prescribed novel in twentieth-century literature courses," as one reason for its obvious manifestations of racism being glossed over. One may add that Conrad's militant denunciation of imperialist enterprises as "a sordid farce," his seemingly radical stance against imperialism, serves as ideological constraints upon his readers, blinding them to its immanent racism. A closer look at the novella's attack on imperialism turns out to be contradictory, for it also shows such liberal-humanist ideas as the civilizing mission, the work ethic, and the superiority of civilized man, all of which served to prop up European imperialism at the end of the nineteenth century. This ideological contradiction also accounts for Conrad's racist attitude, which is betrayed in his portrayal of Africans as obscure, primitive. Euro-American imperialism has frequently justified itself by recourse to racism, but racism has not always been allied with imperialism. Some staunch racists such as Robert Knox and Arthur de Gobineau went against imperialism, and Conrad proves one of such cases whose critique of imperialism is voiced in ways that can be characterized as racist.

• Journal of Dairy Science and Biotechnology
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• v.41 no.3
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• pp.113-125
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• 2023

In this study, we explored the synergistic effects of whey protein concentrate (WPC) and soybean protein components after fermentation with lactic acid bacteria isolated from kimchi, and identified several peptides with desirable physiological functions, proteolysis, and immune effects. Antioxidant activity was determined using 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid, 1,1-diphenyl-2-picrylhydrazyl, ferric-reducing antioxidant power, and hydroxyl radical scavenging assays, followed by cross-validation of the four antioxidant activities. These assays revealed that samples with a 8:2 and 9:1 whey to soy ratio possessed higher antioxidant activity than the control samples. Antibacterial potency testing revealed high antibacterial activity in the 9:1 and 8:2 samples. Cytotoxicity testing of samples using 3-(4, 5-dimethyl thiazol-2-yl)-2, 5-diphenyl tetrazolium bromide revealed that only the 10:0, 1:9, and 0:10 samples had <80% viable cells, indicating no significant cytotoxicity. Nitric oxide (NO) assays revealed that NO expression was reduced in 8:2, 5:5, and 0:10 protein ratio fermentations, indicating low inflammatory reaction stimulatory potential. Cytokine expression was confirmed using an enzyme-linked immunosorbent assay kit. The 8:2 sample had the lowest inflammatory cytokine (interleukin [IL]-1α, IL-6, and tumor necrosis factor-α) levels compared with the lipopolysaccharide-treated group. Amino acid profiling of the 8:2 sample identified 17 amino acids. These results suggest that inoculating and fermenting Lactobacillus plantarum DK203 and Lactobacillus paracasei DK209 with an 8:2 mixture of WPC and soybean protein releases bioactive peptides with excellent anti-inflammatory and antioxidant properties, making them suitable for functional food development.

• Journal of Microbiology and Biotechnology
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• v.34 no.7
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• pp.1452-1463
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• 2024

Fungi generate different metabolites some of which are intrinsically bioactive and could therefore serve as templates for drug development. In the current study, six endophytic fungi namely Aspergillus flavus, Aspergillus tubigenesis, Aspergillus oryzae, Penicillium oxalicum, Aspergillus niger, and Aspergillus brasiliensis were isolated and identified from the medicinal plant, Silybum marianum. These endophytic fungi were identified through intra transcribed sequence (ITS) gene sequencing. The bioactive potentials of fungal extracts were investigated using several bioassays such as antibacterial activity by well-diffusion, MIC, MBC, anti-biofilm, antioxidant, and haemolysis. The Pseudomonas aeruginosa PAO1 was used to determine the antibiofilm activity. The ethyl acetate extract of Aspergillus flavus showed strong to moderate efficacy against Staphylococcus aureus, Escherichia coli, P. aeruginosa, and Bacillus spizizenii. Aspergillus flavus and Aspergillus brasiliensis exhibited significant antibiofilm activity with IC₅₀ at 4.02 and 3.63 mg/ml, while A. flavus exhibited maximum antioxidant activity of 50.8%. Based on HPLC, LC-MS, and NMR experiments kojic acid (1) and carbamic acid (methylene-4, 1-phenylene) bis-dimethyl ester (2) were identified from A. flavus. Kojic acid exhibited DPPH free radical scavenging activity with an IC₅₀ value of 99.3 ㎍/ml and moderate activity against ovarian teratocarcinoma (CH1), colon carcinoma (SW480), and non-small cell lung cancer (A549) cell lines. These findings suggest that endophytic fungi are able to produce promising bioactive compounds which deserve further investigation.

• Korean Journal of Agricultural Science
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• v.50 no.2
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• pp.323-336
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• 2023

As a byproduct obtained from cheese manufacture, whey protein was developed as a functional food that contains multi-functional proteins. In this study, the biochemical activity of fermented milk prepared by fortifying whey protein with excellent physiological activity was investigated. Immunoglobulin (IgG) content was higher in 10% fortified whey protein fermented milk than in the control. The viable cell counts were 20% higher in the fermented milk with 10% fortified whey protein than in the control group. The antibacterial effect of 10% fortified whey protein fermented milk compared to the control group was shown to be effective against four pathogenic microorganisms, Escherichia coli (KCTC1039), Pseudomonas aeruginosa 530, Salmonela Typhimurium (KCTC3216), and Staphylococcus aureus (KCTC1621). The antioxidant effect by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities wasincreased two-fold in 10% fortified whey protein fermented milk compared to the control. The 10% fortified whey protein fermented milk inhibited the expression of the inflammatory cytokines (interleukin [IL]-6, tumor necrosis factor [TNF]-α, and induced nitric oxide synthase [iNOS]) in a concentration-dependent manner. In a piglets feeding test, the weight gain with 10% fortified whey protein fermented milk was increased by 18% compared to the control group, and no diarrhea symptoms appeared. Our results clearly demonstrated that 10% fortified whey protein fermented milk could be a useful functional ingredient for improving health.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.5
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• pp.642-650
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• 2016

Cynanchi wilfordii Radix (CW) and Perilla sikokiana (PS) were extracted under different conditions to study their antioxidant, anti-diabetic, and anti-obesity activities. Their potentials as functional food ingredients were investigated. The highest total phenol contents were $15.74{\pm}0.69mg/g$ for CW100 [100% fermented ethanol (FE) extract from CW] and $39.37{\pm}3.46mg/g$ for PS50 (50% FE extract from PS). When extracts were processed at 1 mg/mL, DPPH radical scavenging activities were $79.79{\pm}0.79%$ and $82.69{\pm}1.07%$, respectively, at CW100 and PS50. ABTS radical scavenging activities were $80.20{\pm}2.86%$ and $75.00{\pm}1.78%$, respectively, at CW100 and PS50. However, ferric reducing antioxidant power activities at 1 mg/mL were higher than 80% for PS under all extraction conditions. The highest ${\alpha}$-amylase inhibitory activities were $51.56{\pm}0.56{\sim}59.2{\pm}1.13%$ at CW50 and $46.70{\pm}0.32{\sim}66.17{\pm}0.55%$ at PS0. Cell differentiation inhibitory effects in 3T3-L1 adipocytes were $29.49{\pm}2.98%$ at CW100 and $23.31{\pm}0.61%$ at PS50. The inhibitory effect of the CW100-PS50 mixture was $43.03{\pm}1.63%$, which was significantly higher than those of individual extracts.

• Korean Journal of Food Science and Technology
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• v.39 no.2
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• pp.209-216
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• 2007

The present study investigated anti-oxidative and anti-inflammatory activity of glycoprotein isolated from Morus Indica Linne (MIL glycoprotein). We found that MIL glycoprotein has a molecular weight of 32 kD and consists of carbohydrate (40.03%) and protein (59.97%), and that it has a strong scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl radical $({\cdot}OH)$, and superoxide anion $(O_2{\cdot}\;^-)$ radicals. In addition, MIL glycoprotein had a stable character and an optimal DPPH radical scavenging activity in the alkaline and neutral pH solution, and up to at 105. However, the results indicated that it has a minimal scavenging activity in the metal ionic solution ($Ca^{2+}$, $Mn^{2+}$, and $Mg^{2+}$) in the presence of EDTA. In addition, we further investigated whether MIL glycoprotein scavenges oxygen radicals and blocks inflammation-related signals in the bisphenol A (BPA)-stimulated Raw 264.7 cells. The results in this study showed that it has a character to scavenge the productions of reactive oxygen species (ROS) and nitric oxide (NO) dose-dependently. Also it blocked the activities of inflammation-related signals such as nuclear factor-kappa B ($NF-{\kappa}B$) and inducible nitric oxide synthase (iNOS). For example, it had an inhibitory effect on the activation of $NF-{\kappa}B$ (p50) and iNOS proteins at 200 ${\mu}g/mL$ MIL glycoprotein. Here, we speculate that MIL glycoprotein is one of natural antioxidants and of modulators of the BPA-induced inflammation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.1
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• pp.44-51
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• 2016

The aim of the study was to investigate the antioxidant content and activities of ethanol extract of the edible flower Dianthus chinensis L. (DCE) as well as its inhibitory activities against nitric oxide (NO) production in macrophages and growth and adhesion of human cancer cells. The total polyphenol, flavonoid, and carotenoid levels of DCE were 19.0 mg gallic acid equivalent/g, 65.7 mg quercetin equivalent/g, and $95.0{\mu}g/g$, respectively. The 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity and ferric reducing antioxidant power of DCE at a concentration of $1,000{\mu}g/mL$ were 44% and 51%, respectively. In lipopolysaccharide-treated RAW 264.7 macrophages, treatment with DCE at concentrations of 500 and $1,000{\mu}g/mL$ resulted in significantly reduced NO levels (to 7~23% of the control). In H1299 human lung carcinoma cells and HCT116 human colorectal carcinoma cells, treatment with DCE at concentrations of 250, 500, and $1,000{\mu}g/mL$ resulted in dose-dependent growth inhibition. DCE was also effective in inhibiting adhesion of both H1299 cells (to 55% of the control at concentration of $1,000{\mu}g/mL$) and HCT116 (to 26~40% of the control at concentrations of 250, 500, and $1,000{\mu}g/mL$). These results suggest that DCE exerts antioxidant, anti-inflammatory, and anti-cancer activities in vitro.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.12
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• pp.1691-1698
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• 2009

The purpose of this study was to investigate the antioxidative and antiallergic effects of persimmon leaf extract. Antioxidative and anti-inflammatory effects of the crude persimmon leaf extract (PLE) and the partially purified persimmon leaf extract (PPLE) were determined in in vitro assays by using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and superoxide anion radicals, and 5-lipoxygenase (5-LO) and cyclooxygenase (COX). Total phenols and total flavonoid levels of PLE and PPLE were $230.0{\pm}19.6$ mg/g and $475.5{\pm}38.7$ mg/g, and $34.8{\pm}6.5$ mg/g and $78.8{\pm}3.6$ mg/g, respectively. DPPH and superoxide radical-scavenging activities ($SC_{50}$) of the PLE and PPLE were $23.8{\pm}3.2$ ppm and $10.0{\pm}1.3$ ppm, and $47.6{\pm}3.4$ ppm and $22.4{\pm}3.3$ ppm, respectively. Inhibitory activities ($IC_{50}$) of PLE and PPLE against 5-LO, COX-1 and COX-2 were $77.1{\pm}11.7$, $38.6{\pm}7.0$ ppm, $47.4{\pm}7.7$, $25.3{\pm}6.3$ ppm, and $129.5{\pm}5.5$, $84.5{\pm}2.3$ ppm, respectively. Moreover, two extracts inhibited dose-dependently NO production in LPS-stimulated RAW 264.7 cells, and also effectively inhibited the cutaneous anaphylaxis reaction activated by anti-dinitrophenyl IgE antibody in mice. These results suggest that PLE and PPLE may be useful for phytochemical materials for prevention and treatment of radical-mediated pathological and allergy diseases.

• Journal of the East Asian Society of Dietary Life
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• v.25 no.1
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• pp.183-192
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• 2015

This study aimed to produce fermented extracts with sugar made from lotus root (LR) and Platycodon grandiflorum (PG), using lactic acid fermentation, and confirmed their physiological and anti-oxidative activities as basic data for manufacturing functional drinks through sensory tests. For the final sugar concentrations, PG showed $48.1^{\circ}brix$ and LR showed $52.0^{\circ}brix$. Sugar concentrations during lactic acid fermentation following dilution of sugar to $12^{\circ}brix$, ranged from $11.5{\sim}12.1^{\circ}brix$ for PG and $11.9{\sim}12.4^{\circ}C$ for LR. During lactic acid fermentation, lactic acid bacteria numbers tended to decrease in both fermented LR and PG extracts with sugar as the fermentation period increased. For DPPH radical scavenging ability, LR was three times higher in control without lactic acid fermentation while PG showed significant increases in L. acidophilus (77%), L. brevis (90%), and L. delbrueckii (177%) during lactic acid fermentation. For total polyphenol content, LR showed a higher concentration than PG, and except for fermented L. delbrueckii extract showing similarity with the control, contents of fermented extracts decreased. In the case of PG, CUPRAC, increased significantly in L. brevis, whereas FRAP, increased significantly in L. delbrueckii with lactic acid fermentation. For reducing power, except for fermentation with L. brevis, all PG showed lower reducing power activities. In the sensory test of fermented LR and PG extracts with sugar, both fermented extracts showed better results with L. brevis or L. delbrueckii than control or those with L. acidophilus in every item. Based on these results, it is highly possible to develop fermented extract drinks with sugar using LR or PG. In particular, lactic acid bacteria such as L. delbrueckii and L. brevis showed generally higher activities with potential as a functional drink.