• Journal of Nutrition and Health
• /
• v.53 no.2
• /
• pp.121-128
• /
• 2020

Purpose: The Rubus coreanus fruit (RF) is an important traditional medicinal herb having antioxidant, anti-inflammatory, and immunoregulatory properties. These activities are known to change dramatically, depending on maturity of the RF. It is presumed that change of functional components, such as flavonoids, tannins, phenolic acids, triterpenoids and organic acids in RF, affect the various bioactivities. This study aimed to confirm changes in the anti-melanogenic effects of RF based on maturity, and to identify the bioactive compounds responsible. Methods: The cell viability of mature RF (MRF) and immature RF (IRF) extracts was investigated using B16F10 cells. To compare the anti-melanogenic effect of MRF and IRF extracts, we first assessed the melanin content. High-performance liquid chromatography analysis was performed to evaluate changes in the level of ellagic acid according to maturity of the RF. In addition, tyrosinase inhibitory activity of both extracts was examined. Results: MRF and IRF extracts (50-200 ㎍/mL) do not affect the cell viability of B16F10 melanoma cells. IRF extract more effectively inhibited melanin synthesis than MRF extract. The content of ellagic acid in IRF extract was higher than that obtained in MRF extract. Furthermore, greater inhibition of tyrosinase activity was observed after exposure to IRF extract than MRF extract. A positive correlation was determined between ellagic acid content and tyrosinase inhibitory activity, and a negative correlation was obtained between ellagic acid content and melanin content. Taken together, our results indicate that ellagic acid is one of the major bioactive compounds of RF that imparts a whitening effect. Conclusion: Our results indicate that ellagic acid in MRF and IRF extracts affect the anti-melanogenesis effect through inhibition of tyrosinase activity. Therefore, the ellagic acid rich IRF has greater potential for application as a natural and functional cosmetic material.

• Journal of Preventive Medicine and Public Health
• /
• v.28 no.2 s.50
• /
• pp.511-525
• /
• 1995

To elucidate some DNA adducts as a biological marker for workers of chromate pigment, the effects of chromium exposure on the formation of 8-hydroxydeoxyguanosine(8-OH-dG) and sister chromatid exchanges(SCEs) frequency in 38 workers of a pigment plant in Bucheon which utilized lead chromates, were examined. The chromium contents of venous blood and urine were measured as working environmental exposure level. The concentrations of 8-OH-dG in DNA isolated from lymphocytes were determined with high performance liquid chromatography and electrochemical detector and denoted as a molar ratio of 8-OH-dG to deoxyguanosine(dG). The SCEs frequency were analyzed in DNA isolated from lymphocytes. A significant correlation was found between creatinine adjusted urine chromium concentration and the molar ratio of 8-OH-dG to dG(r=0.47, p<0.01). After adjusting the current smoking habit, the correlation coefficient was increased(r=0.62, p<0.05). However, there was no significant correlation between the SCE frequency and chromium exposure. This significant results between molar ratio of 8-OH-dG to dG and chromium exposure are in good agreement with in vitro studies that support the importance of DNA adduct formation for the carcinogenic effect of chromium.

• The Korean Journal of Pesticide Science
• /
• v.19 no.2
• /
• pp.81-87
• /
• 2015

The present study was aimed to predict the pre-harvest residue limits (PHRLs) of pyrimethanil (fungicide) and methoxyfenozide (insecticide) in grape, and to estimate their biological half-lives and residual characteristics. The pesticides were sprayed once on grape in two different fields 10 days before harvest. At the end of 0, 1, 2, 3, 5, 7 and 10 days after application, samples were harvested for further analysis. The residual pesticides were extracted with acetonitrile and partitioned with dichloromethane, and the high-performance liquid chromatography with diode array detector (HPLC/DAD) was employed for the residue analysis. The results obtained in the present study show that the limit of detection of both pesticides were found to be $0.01mg\;kg^{-1}$. The recoveries of these pesticides were ranged between 80.6% and 102.5% with coefficient of variation lower than 10%. The biological half-lives of both pesticides were observed in field 1 and field 2 which shows 7.7 and 7.4 days for pyrimethanil and 5.1 and 6.1 days for methoxyfenozide, respectively. Further, the PHRL of pyrimethanil and methoxyfenozide was found to be $8.90mg\;kg^{-1}$ and $5.51mg\;kg^{-1}$, respectively at 10 days before harvest. Consequently, the present study suggests that the residual amounts of both pesticides will be lower than the maximum residue limits (MRLs) when grape is harvested.

• Journal of Food Hygiene and Safety
• /
• v.31 no.2
• /
• pp.94-98
• /
• 2016

This study was conducted to establish the simultaneous analysis method for veterinary drug residues in honey by high performance liquid chromatography tandem mass spectrometry (HPLC/MS/MS). The eleven targeting veterinary drugs with honey test method in Korean Food Standards Codex were divided into Group 1 (streptomycine dihydrostreptomycine, neomycine) and Group 2 (oxytetracycline, enrofloxacin, ciprofloxacin, cymiazole, chloramphenicol, amitraz, coumaphos, fluvalinate) to be analyzed simultaneously. From the results, the retention time (RT) of the targeting drugs was within 15 min, the range of detection limits was 0.0056 to $0.0643{\mu}g/g$ and the range of quantification limits was 0.0169 to $0.1948{\mu}g/g$. The coefficients of determination ($R^2$) for Group 1 ($0.05{\sim}1.0{\mu}g/mL$) and Group 2 ($0.01{\sim}1.0{\mu}g/mL$) were 0.9917~0.9987 and 0.9923~1.000 respectively, and showed the good linearity. The recovery rates for Group 1 (final conc. $0.25{\mu}g/g$) and Group 2 (final conc. $1.0{\mu}g/g$) were 65.1~80.6% and 64.2~90.3% respectively. Also, the analysis results of inter day (n = 3) and intra day (n = 6) RSD (%) for area and retention time showed that the RSD (%) for area and retention time was below 10.92% and 1.57%. Therefore, the simultaneous analysis method of this study is evaluated to be a good test method for veterinary drug residues in honey.

• Korean Journal of Food Science and Technology
• /
• v.36 no.1
• /
• pp.14-18
• /
• 2004

Analysis methods of artificial sweeteners, aspartame, acesulfame potassium, sodium saccharin, and sucralose isolated from foods were developed using high performance liquid chromatography, HPLC conditions for aspartame, acesulfame potassium, and sodium saccharin were: column, Symmetry $C_{18}(3.9mm\;i.d{\times}150mm,\;5{\mu}m)$; mobile phase, 0.05M sodium phosphate monobasic : acetonitrile (9 : 1, pH 3.5, containing 0.01M tetrapropylammonium hydroxide); detector, UV detector at 210 nm. HPLC condition for sucralose were : column, Symmetry $C_{18}(3.9mm\;i.d{\times}150mm,\;5{\mu}m)$; mobile phase, water:methanol (7 : 3); detector, refractive index detection (sensitivity = 16). Recoveries of artificial sweeteners in foods including soft drinks, fruit and vegetable beverages, alcoholic beverages, fermented milk beverages, soybean milk, ice cream, snacks, chewing gums, jam, honey, kimchi salted food, special dietary products, processed fish products, candies, food additive mixtures, chocolate and cocoa were 76.1-101.3%, 82.3-103.2%, 83.1-103.7%, and 80,6-99.5% for aspartame, acesulfame potassium, sodium saccharin, and sucralose, respectively.

• Korean Journal of Food Science and Technology
• /
• v.49 no.6
• /
• pp.668-675
• /
• 2017

To assess the physiological effects of Aruncus dioicus var. kamtschaticus extract on cytoxicity of a neuronal cell line, antioxidant activity, and neuroprotection against intensive glucose-induced oxidative stress were quantitated. Compared to the other fractions, the ethyl acetate fraction of Aruncus dioicus var. kamtschaticus (EFAD) showed the highest total phenolics and flavonoids. The 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) assay and malondialdehyde inhibitory effect test confirmed the superior antioxidant activity of EFAD. Moreover, EFAD also decreased the intracellular ROS level and suppressed neuronal cell death against intensive glucose- or $H_2O_2$-induced oxidative stress. Additionally, assessment of ${\alpha}$-glucosidase and acetylcholinesterase inhibitory activities revealed that EFAD was an effective inhibitor of ${\alpha}$-glucosidase and acetylcholinesterase. Finally, high-performance liquid chromatography analysis identified caffeic acid as the main ingredient of EFAD. Overall, these results suggest that the EFAD is a good natural source of biological compounds that counteract hyperglycemic neuronal defects.

• Clinical and Experimental Pediatrics
• /
• v.46 no.8
• /
• pp.789-794
• /
• 2003

Purpose : We intended to evaluate the effect of hypoxia-ischemia on extracellular striatal monoamine metabolism in neonatal rat brains by in vivo microdialysis. Methods : The right common carotid arteries of five or six-day old rats were surgically ligated, and the probes for microdialysis were inserted into the right striatum with stereotaxic instrument. After stabilization for two hours, artificial cerebrospinal fluid was infused via the probe for microdialysis and samples were collected during hypoxia-ischemia and recovery periods at 20 minute intervals. The concentrations of DA(dopamine), DOPAC(3,4-di-hydroxyphenyl acetic acid), HVA(homovanillic acid), NE(norepinephrine), and 5-HIAA(5-hydroxy indole-acetic acid) were measured by HPLC(high performance liquid chromatography) and the changes were analysed. Results : The striatal levels of dopamine metabolites such as DOPAC and HVA, were significantly decreased during hypoxia-ischemia, and increased to their basal level during reoxygenation(P<0.05). Dopamine mostly increased during hypoxia but statistically not significant(P>0.05). DOPAC showed the most remarkable decrease($23.0{\pm}4.2%$, P<0.05), during hypoxia-ischemia and increase to the basal levels during reoxygenation($120.8{\pm}54.9%$, P<0.05), and HVA showed the same pattern of changes as those of DOPAC during hypoxia-ischemia($35.3{\pm}7.6%$ of basal level, P<0.05) and reoxygenation ($105.8{\pm}32.3%$). However, the level of NE did not show significant changes during hypoxia-ischemia and reoxygenation. The levels of 5-HIAA decreased($74.9{\pm}3.1%$) and increased($118.1{\pm}7.8%$) during hypoxia-ischemia and reoxygenation, respectively(P<0.005). Conclusion : Hypoxia-ischemia had a significant influence on the metabolism of striatal monoamine in neonatal rat brains. These findings suggest that monoamine, especially dopamine, and its metabolites could have a significant role in the pathogenesis of hypoxic-ischemic injury of neonatal rat brains.

• The Korean Journal of Pesticide Science
• /
• v.21 no.1
• /
• pp.68-74
• /
• 2017

An analytical method for detecting metamifop residue in paddy water, soil, and rice with high performance liquid chromatography (HPLC) was developed. Water was extracted with ethyl acetate before analyzing by HPLC. Soil residues were extracted with acetone under acidic condition and after purifying with $Extrelut^{(R)}$ NT, and silica SPE, the residue was analyzed by HPLC. For residue analysis in rice, the procedure involved extraction with acetone, purification with $Extrelut^{(R)}$ NT, partitioning between acetonitrile/hexane, purification with silica SPE cartridge, and analysis by HPLC. The limit of detection (LOD) was 1.0 ng, limit of quantitation (LOQ) was 3.0 ng, and method limit of quantitation (MLOQ) were 0.001 mg/L for paddy water, 0.01 mg/kg for rice and soil, respectively. Standard calibration curve shows linearity from 0.05 mg/kg to 5.0 mg/kg ($R^2=0.9999$). The recoveries in fortified paddy water were $91.3{\pm}3.5%$ (0.01 mg/L level) and $93.2{\pm}6.3%$ (0.05 mg/L level). The recoveries in fortified paddy soils were $92.5{\pm}4.0%$ (0.1 mg/kg level) and $92.7{\pm}4.0%$ (0.5 mg/kg level) in soil A, while, $102.3{\pm}4.4%$ (0.1 mg/kg level) and $98.9{\pm}7.9%$ (0.5 mg/kg level) in soil B, respectively. The recoveries in fortified rice were $93.0{\pm}6.9%$ (0.1 mg/kg level) and $85.0{\pm}3.5%$ (0.5 mg/kg level). This method was proved to be effective and can be used to determine the metamifop residue in paddy water, paddy soil, and rice.

• Food Science and Preservation
• /
• v.23 no.4
• /
• pp.560-567
• /
• 2016

Sensory evaluation, in vitro antioxidant activities and main compounds of coffee water-extract, coffee liqueur (CL) and coffee-ground liqueur (CGL) were investigated to consider their industrialization. Sensory evaluation showed that all groups of CGL without 25% CGL (3 month) were relatively higher than CL groups. Total phenolic compounds and in vitro antioxidant activities such as 1,1-diphenyl-2picryl-hydrazyl (DPPH) radical scavenging activity and ferric reducing/antioxidant power (FRAP) were also performed. The group of 35% CGL had higher total phenolic compounds than others, and the result of DPPH radical scavenging activity was similar to that of total phenolic compounds. In addition, 35% CGL is comparable to the FRAP of coffee water extract (CE). Qualitative and quantitative analysis using high-performance liquid chromatography (HPLC) were performed, and chlorogenic acid as a ployphenolic compound and caffeine as a nonpolyphenolic compound were detected in all samples. Moreover, the HPLC analysis showed that CGLs contain a larger amounts of chlorogenic acid (difference of 0.3~10.5%) and also greater amounts of caffeine (difference of 10.0~18.2%) more then CE. Consequently, these results suggest that coffee-ground as coffee by-products could be used as commercially available food substances because of its physiological molecules remained.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.46 no.2
• /
• pp.210-219
• /
• 2017

This study aimed to establish an optimal extraction process and high-performance liquid chromatography (HPLC)-photodiode array (PDA) analytical method for determination of marker compounds, dihydrokaempferol (DHK) and 3-O-methylquercetin (3-MeQ), as a part of materials standardization for the development of health functional foods from stems of Opuntia ficus-indica var. saboten (OFS). The quantitative determination method of marker compounds was optimized by HPLC analysis, and the correlation coefficient for the calibration curve showed very good linearity. The HPLC-PDA method was applied successfully to quantification of marker compounds in OFS after validation of the method in terms of linearity, accuracy, and precision. Ethanolic extracts from stems of O. ficus-indica var. saboten (OFSEs) were evaluated by reflux extraction at 70 and $80^{\circ}C$ with 50, 70, and 80% ethanol for 3, 4, 5, and 6 h. Among OFSEs, OFS70E at $80^{\circ}C$ showed the highest contents of DHK and 3-MeQ of $26.42{\pm}0.65$ and $3.88{\pm}0.29mg/OFS100g$, respectively. Furthermore, OFSEs were determined for their antioxidant activities by measuring 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and lipid peroxidation (LPO) inhibitory activities in rat liver homogenate. OFS70E at $70^{\circ}C$ showed the most potent antioxidant activities with $IC_{50}$ values of $1.19{\pm}0.11$ and $0.89{\pm}0.09mg/mL$ in the DPPH radical scavenging and LPO inhibitory assays, respectively. To identify active components of OFS, various chromatographic separation of OFS70E led to isolation of 11 flavonoids: dihydrokaempferol, dihydroquercetin, 3-O-methylquercetin, quercetin, isorhamnetin 3-O-glucoside, isorhamnetin 3-O-galactoside, narcissin, kaempferol 7-O-glucoside, quercetin 3-O-galactoside, isorhamnetin, and kaempferol 3-O-rutinoside. The results suggest that standardization of DHK in OFSEs using HPLC-PDA analysis would be an acceptable method for the development of health functional foods.