• Journal of Applied Biological Chemistry
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• v.65 no.4
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• pp.357-365
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• 2022

We examined the lung anti-fibrotic properties of flavanones and flavones, which are flavonoid compounds, in bleomycin- and TGF-β1-stimulated A549 cells. Taken together, treatment with Bleomycin and TGF-β1 increased intracellular ROS by increasing the expression of various NOX families in A549 cells; further, the increased ROS levels resulted in increased fibrosis markers and induced pulmonary fibrosis. Flavonoid treatment has been demonstrated to alleviate or inhibit pulmonary fibrosis by modulating Smad-dependent and -non-dependent TGF-β mechanisms by modulating intracellular NOX expression.

• Journal of Nutrition and Health
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• v.48 no.6
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• pp.507-518
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• 2015

Purpose: The aim of this study was to examine the association of food security with the total and individual flavonoid intakes among Korean adults. Methods: Study subjects were 13,454 men and 19,563 women aged 19 years and older who participated in the 2007~2012 Korea National Health and Nutrition Examination Survey. Subjects were classified into food-secure and food-insecure groups using the answers to a self-reported question on food sufficiency of subjects' household. The total and individual flavonoid intakes were calculated by linking 24-h dietary recall data of subjects with a flavonoid database. Mean differences in dietary outcomes by food security status, and major food sources of total flavonoids were examined. Results: In this cross-sectional study, 5.8% of male adults and 6.6% of female adults were in food insecure households. Mean daily intakes of total flavonoids, flavonols, flavones, flavanones, flavan-3-ols, isoflavones, and proanthocyanidins were significantly lower in food-insecure groups than food-secure groups among both male and female adults. The differences were maintained in total flavonoids, flavones, flavanones, and flavan-3-ols after adjusting for total energy intake. Mean intakes of fruits and vegetables were significantly lower in food-insecure groups and the total flavonoid intake from fruits and vegetables was also significantly lower in food-insecure groups. The major food sources of total flavonoids were apples (20.7%), mandarines (12.0%), and tofu (11.5%) in the food-secure group, and apples (14.9%), tofu (13.3%), and mandarines (12.6%) in the food-insecure group. Conclusion: This study showed that food insecurity was associated with lower intakes of flavonoids and reduced intakes of fruits and vegetables in a representative Korean population.

• Journal of Nutrition and Health
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• v.48 no.6
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• pp.496-506
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• 2015

Purpose: The purpose of this study was to estimate dietary flavonoids intake of Korean adolescents. Methods: Using data from the 2007-2012 Korean National Health and Nutrition Examination Survey, a total of 3,957 subjects aged 12-18 were included in this study. We estimated individual daily intake of total flavonoid and six flavonoid classes including flavonols, flavones, flavanones, flavan-3-ols, anthocyanidins, and isoflavones by linking food consumption data with the flavonoids in the commonly consumed food database. The distribution of sociodemographic, health-related, and dietary factors according to flavonoids intake was examined. Results: Average dietary flavonoids intake of the study subjects was 195.6 mg/d in girls, and 189.4 mg/d in boys. The highest flavonoids intake group consumed significantly more fiber, vitamin C, legumes, fruits, and vegetables (p < 0.01) and less fat, grains, meats and dairy foods than other lower consumption groups (p < 0.001). Dietary flavonoid intake showed negative correlation with waist circumference and systolic blood pressure (p < 0.05). Conclusion: This study provided basic data for estimation of flavonoids intake of Korean adolescents. Further research will be required for analysis of the association of flavonoids intake and health-related factors such as cardiovascular risk factors.

• Journal of Life Science
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• v.27 no.4
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• pp.476-481
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• 2017

Polyphenols are secondary metabolites produced by higher plants and have been used as antiallergic, anticancer, antihypertensive, antiinflammatory, antimicrobial and antioxidant agents. They are generally divided into flavonoids and non-flavonoids. The antimicrobial activity of flavonoids are stronger than that of non-flavonoids. The skeleton structures of flavonoids possessing antimicrobial activity are chalcone, flavan-3-ol (catechin), flavanone, flavone, flavonol and proanthocyanidin. The flavonols are shown antibacterial activity against several gram-positive bacteria (Actinomyces naeslundii, Lactobacillus acidophilus and Staphylococcus aureus) and gram-negative bacteria (Fusobacterium nucleatum, Porphyromonas gingivalis, Prevotella melaninogenica and Prevotella oralis). Among of non-flavonoids, caffeic acids, ferulic acids and gallic acids showed antimicrobial activity against gram-positive (Listeria monocytogenes and S. aureus) and gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa). These are found to be more efficient against the E. coli, L. monocytogenes, P. aeruginosa and S. aureus than antibiotics such as gentamicin and streptomycin. The kaempferol and quercetin showed synergistic effect with ciprofloxacin and rifampicin against S. aureus and methicillin resistant S. aureus (MRSA). Epigallocatechin gallate (EGCG) acts synergistically with various ${\beta}-lactam$ antibiotics against MRSA. In particular, the epicatechin, epigallocatechin (EGC), EGCG and gallocatechin gallate from Korean green tea has antibacterial activity against MRSA clinical isolates and the combination of tea polyphenols and oxacillin was synergistic for all the clinical MRSA isolates.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.3
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• pp.331-337
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• 2015

Citrus and its peels, which are by-products from juice and/or jam processing, have long been used in Asian folk medicine. Citrus peels show an abundant variety of flavanones, and these flavanones have glycone and aglycone forms. Aglycones are more potent than glycones with a variety of physiological functions since aglycone absorption is more efficient than glycones. Bioconversion with cytolase converted narirutin and naringin into naringenin and hesperidin into hesperetin. Therefore, this study aimed to investigate the anti-oxidant and anti-inflammatory effects of bioconversion of Citrus unshiu (CU) peel extracts with cytolase (CU-C) in RAW264.7 cells. HPLC chromatograms showed that CU and CU-C had 23.42% and 29.39% total flavonoids, respectively. There was substantial bioconversion of narirutin to naringenin and of hesperidin to hesperetin. All citrus peel extracts showed DPPH scavenging activities in a dose-dependent manner, and CU-C was more potent than intact CU. RAW264.7 cells were pre-treated with $0{\sim}500{\mu}g/mL$ of citrus peel extracts for 4 h and then stimulated by $1{\mu}g/mL$ of lipopolysaccharide (LPS) for 8 h. All citrus peel extracts showed decreased mRNA levels and protein expression of LPS-induced inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in a dose-dependent manner. Especially, CU-C markedly inhibited mRNA and protein expression of iNOS and COX-2 compared to intact citrus peel extracts. All citrus peel extracts showed decreased NO production by iNOS activity. This result suggests that bioconversion of citrus peel extracts with cytolase may provide potent functional food materials for prevention of chronic diseases attributable to oxidation and inflammation by boosting the anti-inflammatory effects of citrus peels.

• Journal of Nutrition and Health
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• v.50 no.4
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• pp.391-401
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• 2017

Purpose: The purpose of this study was to estimate the dietary flavonoid intakes of Korean adults according to socioeconomic status. Methods: Using data from the 2007~2012 Korea National Health and Nutrition Examination Survey, a total of 31,112 subjects aged over 19 years were included in this study. We estimated individuals' daily intakes of total flavonoids and seven flavonoid subclasses, including flavonols, flavones, flavanones, flavan-3-ols, anthocyanins, proanthocyanidin, and isoflavones,by linking food consumption data with the flavonoids database for commonly consumed Korean foods. We compared intakes of flavonoids according to the levels of household income and education. Results: Average dietary flavonoid intakes of the study subjects were 321.8 mg/d in men and 308.3 mg/d in women. Daily flavonoid intakes were positively associated with household income level (p < 0.0001) and education level (p < 0.0001). The subjects in the highest household income and highest education level group (OR 0.37, 95% CI 0.30~0.45, p < 0.0001 in men, OR 0.50, 95% CI 0.41~0.60, p < 0.0001 in women) had a lower likelihood of having low total flavonoid intake (less than 25 percentile) compared to the lowest household income and lowest education level group. The food group that contributed to total flavonoid intake with the biggest difference between the lowest and highest groups for both household income level and education level was beverages. Conclusion: This study shows that socioeconomic status was positively associated with flavonoid intake in a representative Korean population. Further research is needed to analyze the association of flavonoid intake with health outcomes according to socioeconomic status such as household income and education level.

• Journal of Nutrition and Health
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• v.50 no.3
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• pp.246-256
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• 2017

Purpose: This study aimed to investigate the association of total dietary antioxidant capacity (TAC) with oxidative stress and metabolic markers among patients with metabolic syndrome according to gender. Methods: A total of 346 subjects aged 30~59 years with two or more risk factors of metabolic syndrome were recruited from a general hospital near Seoul in South Korea between 2010 and 2012 based on data from the medical checkup. Biochemical indices for oxidative stress and metabolic markers were measured. Food consumption data from 3-day food records were linked with the antioxidant capacity database for commonly consumed Korean foods to estimate individual's TAC. Results: Average dietary TAC of the study subjects was 132.0 mg VCE/d/1,000 kcal in men and 196.4 mg VCE/d/1,000 kcal in women. Levels of ${\gamma}$-glutamyltransferase (GGT), systolic blood pressure, diastolic blood pressure, and blood triglycerides were reduced significantly according to increasing TAC in men, but there was no significant trend in women. Intakes of total flavonoids and carotenoids were significantly negatively correlated with GGT (p < 0.05) and d-ROMs (p < 0.01) in men, whereas those of ${\alpha}$-tocopherol (p < 0.05) and ${\gamma}$-tocopherol (p < 0.05) were positively correlated with biological antioxidant potential (BAP) in women. The odds ratio of high oxidative stress indices and abnormal metabolic markers according to TAC level were not significant in either men or women. Conclusion: The results show that dietary TAC was partially associated with oxidative stress and metabolic markers among patients with metabolic syndrome. Further research is required for elucidating the association between dietary TAC and incidence of metabolic syndrome and chronic diseases within a large population in prospective studies.