• The Korea Journal of Herbology
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• v.34 no.4
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• pp.19-25
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• 2019

Objectives : Thymol (2-isopropyl-5-methylphenol), a natural monoterpenoid phenol, is one of the major odorant constituents found in natural essential oils of various herbal plants, such as Thymus quinquecostatus and Thymus vulgaris. Multiple biological activities of thymol, including antioxidative, antimicrobial, and anti-inflammatory effects, have been reported in numerous in vitro studies, and recently it was suggested that thymol may could inhibit oxidization of L-dihydroxyphenylalanine (L-DOPA) to dopaquinone required in melanogenesis pathway, as an antioxidant. Methods : MTT assay was performed to test the cytotoxic effect of thymol in B16F10 cells. Inhibitory effect of thymol to tyrosinase activities were examined using both mushroom tyrosinase and intracellular tyrosinase. Expression level of tyrosinase in B16F10 cells were investigated by western blot analysis. Results : The cell viability was decreased by thymol treatment in dose-dependant manner, leading significant cytotoxicity in 500 and $1000{\mu}M$ thymol-treated groups. In the alpha-melanocyte stimulating hormone (${\alpha}$-MSH)-induced melanogenesis, administration of thymol significantly decreased extracellular (secreted) melanin content in dose-dependent manner. Cellular tyrosinase activity assay and western blot analysis of intracellular tyrosinase showed that thymol has a strong anti-melanogenic effect by inhibition of tyrosinase activity and by decreasing expression of tyrosinase that contribute to melanin synthesis in the B1610 cells. Conclusions : As the first functional study that prove anti-melanogenic effect of thymol and its underlying mechanism in the living cells, our study suggests the applicability of fragrance as the functional materials of cosmetics or health supplement, not as just an additive.

• Journal of Animal Science and Technology
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• v.64 no.2
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• pp.312-329
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• 2022

Feed cost is the main factor affecting the economic benefits of pig industry. Improving the feed efficiency (FE) can reduce the feed cost and improve the economic benefits of pig breeding enterprises. Liver is a complex metabolic organ which affects the distribution of nutrients and regulates the efficiency of energy conversion from nutrients to muscle or fat, thereby affecting feed efficiency. MicroRNAs (miRNAs) are small non-coding RNAs that can regulate feed efficiency through the modulation of gene expression at the post-transcriptional level. In this study, we analyzed miRNA profiling of liver tissues in High-FE and Low-FE pigs for the purpose of identifying key miRNAs related to feed efficiency. A total 212~221 annotated porcine miRNAs and 136~281 novel miRNAs were identified in the pig liver. Among them, 188 annotated miRNAs were co-expressed in High-FE and Low-FE pigs. The 14 miRNAs were significantly differentially expressed (DE) in the livers of high-FE pigs and low-FE pigs, of which 5 were downregulated and 9 were upregulated. Kyoto Encyclopedia of Genes and Genomes analysis of liver DE miRNAs in high-FE pigs and low-FE pigs indicated that the target genes of DE miRNAs were significantly enriched in insulin signaling pathway, Gonadotropin-releasing hormone signaling pathway, and mammalian target of rapamycin signaling pathway. To verify the reliability of sequencing results, 5 DE miRNAs were randomly selected for quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The qRT-PCR results of miRNAs were confirmed to be consistent with sequencing data. DE miRNA data indicated that liver-specific miRNAs synergistically acted with mRNAs to improve feed efficiency. The liver miRNAs expression analysis revealed the metabolic pathways by which the liver miRNAs regulate pig feed efficiency.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2002.11a
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• pp.99-99
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• 2002

The hormone resistin is associated with typeII diabetes mellitus in rodent model. Resistin impairs glucose tolerance and insulin action. A new class of anti-diabetic drugs were called thiazolidinediones (TZDs) downregulates a resistin which is induced during adipocyte differentiation. But the connection between increased adiposity and resistin remains unknown. The objectives of this study was to clone a mouse resistin cDNA and to generate transgenic mice overexpressing mouse resistin gene. The 555 bp of mouse resistin was amplified from mob cDNAS by polymerase chain reaction (PCR) and cloned into pCR$\^$(R)/ 2.1 TOPO T-vector. Mouse resistin mRNA on the basis of Genbank sequence (acession no. AF323080). Then, the PCR product was cloned into pTargeT$\^$TM/ mammalian expression vector that has pCMV promoter and chimeric intron. Restriction enzyme analysis with BamH I and Not I was carried out to determine an orientation of the insert in the vector. The pCMV-mus/resistin gene was prepared from previous recombinant pTargeT$\^$TM/-mus/resistin by digestion of Bgl II, and has used for microinjection into pronuclei of one cell embryos. The microinjected embryos were transfered to pseudopregnant foster-mother. Mouse resistin expression was detected in transgenic F1 mice by Reverse Transcriptase- Polymerase Chain Reaction (RT-PCR). Resistin gene expression mouse has heavier body weight which was measured higher level of plasma glucose than that of normal mouse. And in diet-induced experiments, the abdominal fat pads were isolated from each 24h starvation and re-feeding after fasting group mice that were assessed by RT-PCR analysis. In fasting group mice, resistin expression was higher than that of re-feeding group mice. This result suggests that the resistin gene overexpressing mice may be became to obesity and be useful as an animal disease model to be diabetes mellitus caused by insulin resistance of resistin.

• Journal of Animal Reproduction and Biotechnology
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• v.38 no.2
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• pp.62-69
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• 2023

Background: Research on the reproductive physiology of Water and Sika deer, an endemic in Korea, still needs to be completed. This study analyzed the ovarian development and morphological characteristics of wild Water deer and Sika deer. Methods: Water deer and Sika deer ovaries were collected from the Korean Peninsula and Russia-Korean Peninsula border during the estrus and pregnancy seasons, respectively. And, morphological and physiological analysis and immunohistochemistry were conducted to confirm the detection of Ca²⁺ and assess the morphological changes in the ovaries. Results: The results of morphological analysis of ovaries during pregnancy and estrus, the development of the corpus luteum and follicles of Water deer showed similar patterns to other mammals. In contrast, the corpus luteum of Sika deer differed in tissue morphology and composition from Water deer. Ca²⁺ related to tissue metabolism was detected in the theca cells zone of Water deer on the estrus and was highly detected in the luteum cells zone during pregnancy. The hormone receptor protein expression patterns were generally higher in the ovaries of Water deer on the estrus and the pregnancy than in Sika deer. The expression of LH receptor was relatively low in the lutein cell zone, unlikely that of Water deer. The expression of VEGF was also different from Water deer, and the response in Sika deer was relatively very low compared to Water deer in expressing all proteins-related development. Conclusions: Therefore, the results of the study were shown that the composition of the corpus luteum of Sika deer is not clear compared to Water deer, and there are many differences in the functional and morphological formation of the corpus luteum.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2023.04a
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• pp.23-23
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• 2023

The Hairy labrador tea (Ledum palustre L. var. diversipilosum Nakai) is a evergreen small shrub, belonging to the Ericaceae and mainly distributed along the alpine areas of Hamgyeong-do in North Korea. Through seed physiological research on North Korean plants, we intend to obtain basic data for the development of mass propagation methods and use them for vegetation restoration. The internal and external morphological characters of the seed were observed using scanning electron microscopy or stereoscopy, and full seeds were selected through X-ray test. Seeds were cultured on a growth condition at 15/6℃ and 25/15℃ to examine the germination response according to temperature, and the number of germinated individuals was examined every 24 hours to calculate germination percentage and mean germination time. Low-temperature treatment (4℃) and hormone treatment (GA3) were performed to investigate the effect of dormancy breaking, and analysis of variance (ANOVA) was performed on the experimental results using SAS 9.4. The seeds of the Hairy labrador tea were elliptical-narrow in shape, and the epidermal cell wall pattern was reticulated. The final germination rate (FGP) was the highest at 58.9% under the condition of low temperature treatment at 25/15℃. The average number of days to germination (MGT) was the highest at 25.1 days without treatment at 15/6℃, and the average of the last germination days was confirmed to be about 13 days. As a result of low temperature treatment, it was confirmed that the final germination rate (FGP) increased by 43.3%. The significance of the final germination rate (FGP) was verified according to the pretreatment at 25/15℃.

• Journal of the Korean Chemical Society
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• v.68 no.4
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• pp.191-198
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• 2024

Endocrine disrupting chemicals (EDCs) are compounds that come from outside the body and disrupt hormone action within the body's endocrine system. Examples include parabens, benzophenones, bisphenols, and phthalates, which are currently used in a wide range of applications. However, continuous exposure to them can have negative effects on glycemic control, reproduction, metabolism, nervous system development, pregnancy, childbirth, and growth. In this study, human samples (urine) were pretreated using liquid-liquid-extraction to determine the exposure level of EDCs and then analyzed effectively and rapidly by UPLC-MS/MS. In this way, the analytical conditions were established and the reliability of the simultaneous analysis method was evaluated through method validation. The results showed that the accuracy ranged from 75.28 to 122.36% and the precision ranged from 2.16 to 22.74%. The analytical method established in this study can be used as a methodology for future studies to evaluate and monitor the exposure of EDCs in human samples.

• Journal of Food Hygiene and Safety
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• v.25 no.3
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• pp.226-231
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• 2010

We aimed at the monitoring medroxyprogesterone acetate (MPA) residue amount in meats and confirmed the safety of its residue in meats. Optimized condition for analytical and instrumental methods was obtained by method validation. The limit of detection (LOD) and limit of quantification (LOQ) were validated at 1.5 and 5.0 ug/kg, respectively. The calibration curve showed good linearity ($r^2$ = 0.9968) within the concentration range of 5.0~50.0 ug/kg. We selected progesterone-d9 for internal standard, The recoveries in fortified meat ranged from 67.5 to 109.56% at the 3 spiking levels. As the regulation of MPA analysis method used by LC-MS/MS on other products have established. We selected 3 species of farm stock products (cattle, pig, chicken) and purchased at the markets of seven major cities. The total 196 of meat including 46 of domestic beef, 43 of import beef, 60 of domestic pork, 12 of import pork and 35 of domestic chicken. No residue of synthetic growth hormones were detected in cattle, pig and chicken samples tested.

• Journal of Food Hygiene and Safety
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• v.38 no.3
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• pp.184-191
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• 2023

Nuts are essential components of a healthy diet as they provide nutritional value and bioactive components. Melatonin, is a hormone secreted from the pineal gland of the brain that prevents oxidative damage in various tissues, and also found in plants. This study presents a validation method for extracting and quantitatively analyzing melatonin in nuts, seeds, and beans in Gyeonggi-do; the method utilized chromatographic techniques and optimized extraction procedures, considering the high oil content of nuts. The average content of melatonin in nuts, seeds, and beans was 1200.83 (409.76-2223.56), 934.83 (454.10-1736.60), and 616.46 (494.70-825.12) pg/g, respectively. Melatonin content was higher in the kernel with pellicle than that in the kernel alone in walnuts and chestnuts. Furthermore, the presence of melatonin was lower in newly harvested walnuts, chestnuts, and peanuts than in those stored after being harvested the previous year.

• Development and Reproduction
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• v.6 no.2
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• pp.131-139
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• 2002

Since GnRH and its receptor genes are expressed in the ovary, it has been suggested that ovarian GnRH might be involved in the regulation of ovarian function and the apoptosis of ovarian cells. However, it was not known well on the expression and function of GnRH and its receptor in the corpus luteum. The present study was undertaken to investigate whether GnRH and its receptor are expressed in luteal cells and GnRH has any effect on the apoptosis of luteal cells. Luteal cells obtained from the pregnant rats were cultured and stained for GnRH and its receptor proteins. Cultured luteal cells showed distinct immunoreactivity against both anti-GnRH and anti-GnRH receptor antibodies. In addition, the presence of GnRH receptor protein in cultured cells was confirmed by Western blot analysis. To investigate the effect of GnRH on the apoptosis of luteal cells, luteal cells were cultured in the presence of 10$^{-6}$ M GnRH-agonist(GnRH-Ag) for 3, 8, and 12h. TUNEL assay showed that the number of cells undergoing apoptosis increased 12h after culture(P<0.05). DNA fragmentation analysis confirmed the results such that the cells treated for 12h showed the greatest increase of fragmentation(p<0.05). Further, Western blot analysis of cytochrome c in the mitochondrial and cytoplasmic fractions of the luteal cells showed that GnRH-Ag treatment increased the content of cytochrome c in cytoplasm. These results demonstrate that the luteal cells express GnRH and its receptor and GnRH-Ag treatment induces apoptosis of the luteal cells via mitochondrial release of cytochrome c. The present study suggest that the releasing of cytochrome c from mitochondria might be involved in the luteal cell apoptosis induced by GnRH-Ag.

• Korean Journal of Clinical Pharmacy
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• v.30 no.1
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• pp.1-10
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• 2020

Objective: The aim of the study was to perform a meta-analysis of randomized clinical trials to compare the clinical efficacy and safety between combination of cyclin-dependent kinase (CDK) 4/6 inhibitors with aromatase inhibitors (AIs) and AIs alone in patients with hormone receptor+/human epidermal growth factor receptor type2-(HR+/HER2-) advanced breast cancer. Methods: Published clinical studies were identified through electronic database searches until February 2019. Literature qualities were assessed by the Scottish Intercollegiate Guidelines Network Checklist. Key endpoints of efficacy were progression-free survival (PFS), objective response rate (ORR), and clinical benefit (CB). Endpoints of safety were adverse events (AEs) (neutropenia, leukopenia, any grade 3/4 AEs, and serious AEs) and on-treatment death. Meta-analysis was performed using the RevMan 5.3 software. Results: The selected five studies were evaluated as "good" in quality assessment. Compared to AIs alone, the combination therapy significantly improved PFS (pooled hazard ratio=0.55; 95% confidence interval (CI) 0.49-0.62), ORR (odds ratio=1.78; 95% CI=1.49-2.13), and CB (odds ratio=1.86; 95% CI=1.51-2.28). The prevalence of AEs was significantly higher in the combination group than in the AIs alone group. On-treatment death was greater in the combination group than in the AIs alone group, although insignificant. Conclusion: The combination therapy of CDK4/6 inhibitors with AIs was more effective for the treatment of HR+/HER2- advanced breast cancer, but less safe than AIs alone. The combination therapy should be effectively managed through patient monitoring, and further studies are needed to reduce AEs in the combination therapy of CDK4/6 inhibitors with AIs.