• Nutrition Research and Practice
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• v.17 no.5
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• pp.870-882
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• 2023

BACKGROUND/OBJECTIVES: Obesity is a major risk factor for metabolic syndrome, a global public health problem. Mentha canadensis (MA), a traditional phytomedicine and dietary herb used for centuries, was the focus of this study to investigate its effects on obesity. MATERIALS/METHODS: Thirty-five male C57BL/6J mice were randomly divided into 2 groups and fed either a normal diet (ND, n = 10) or a high-fat diet (HFD, n = 25) for 4 weeks to induce obesity. After the obesity induction period, the HFD-fed mice were randomly separated into 2 groups: one group continued to be fed HFD (n = 15, HFD group), while the other group was fed HFD with 1.5% (w/w) MA ethanol extract (n = 10, MA group) for 13 weeks. RESULTS: The results showed that body and white adipose tissue (WAT) weights were significantly decreased in the MA-supplemented group compared to the HFD group. Additionally, MA supplementation enhanced energy expenditure, leading to improvements in plasma lipids, cytokines, hepatic steatosis, and fecal lipids. Furthermore, MA supplementation regulated lipid-metabolism-related enzyme activity and gene expression, thereby suppressing lipid accumulation in the WAT and liver. CONCLUSIONS: These findings indicate that MA has the potential to improve diet-induced obesity and its associated complications, including adiposity, dyslipidemia, hepatic steatosis, and inflammation.

• Reproductive and Developmental Biology
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• v.33 no.3
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• pp.163-169
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• 2009

Many biological systems are regulated by an intricate set of feedback loops that oscillate with a circadian rhythm of roughly 24 h. This circadian clock mediates an increase in body temperature, heart rate, blood pressure, and cortisol secretion early in the day. Recent studies have shown changes in the amplitude of the circadian clock in the hearts and livers of streptozotocin (STZ)-treated rats. It is therefore important to examine the relationships between circadian clock genes and growth factors and their effects on diabetic phenomena in animal models as well as in human patients. In this study, we sought to determine whether diurnal variation in organ development and the regulation of metabolism, including growth and development during the juvenile period in rats, exists as a mechanism for anticipating and responding to the environment. Also, we examined the relationship between changes in growth factor expression in the liver and clock-controlled protein synthesis and turnover, which are important in cellular growth. Specifically, we assessed the expression patterns of several clock genes, including Per1, Per2, Clock, Bmal1, Cry1 and Cry2 and growth factors such as insulin-like growth factor (IGF)-1 and -2 and transforming growth factor (TGF)-${\beta}1$ in rats with STZ-induced diabetes. Growth factor and clock gene expression in the liver at 1 week post-induction was clearly increased compared to the level in control rats. In contrast, the expression patterns of the genes were similar to those observed after 5 weeks in the STZ-treated rats. The increase in gene expression is likely a compensatory change in response to the obstruction of insulin function during the initial phase of induction. However, as the period of induction was extended, the expression of the compensatory genes decreased to the control level. This is likely the result of decreased insulin secretion due to the destruction of beta cells in the pancreas by STZ.

• Annals of Pediatric Endocrinology and Metabolism
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• v.23 no.4
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• pp.204-209
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• 2018

Purpose: Growth hormone transduction defect (GHTD) is characterized by severe short stature, impaired STAT3 (signal transducer and activator of transcription-3) phosphorylation and overexpression of the cytokine inducible SH2 containing protein (CIS) and p21/CIP1/WAF1. To investigate the role of p21/CIP1/WAF1 in the negative regulation of the growth hormone (GH)/GH receptor and Epidermal Growth Factor (EGF)/EGF Receptor pathways in GHTD. Methods: Fibroblast cultures were developed from gingival biopsies of 1 GHTD patient and 1 control. The protein expression and the cellular localization of p21/CIP1/WAF1 was studied by Western immunoblotting and immunofluorescence, respectively: at the basal state and after induction with $200-{\mu}g/L$ human GH (hGH) (GH200), either with or without siRNA CIS (siCIS); at the basal state and after inductions with $200-{\mu}g/L$ hGH (GH200), $1,000-{\mu}g/L$ hGH (GH1000) or 50-ng/mL EGF. Results: After GH200/siCIS, the protein expression and nuclear localization of p21 were reduced in the patient. After successful induction of GH signaling (control, GH200; patient, GH1000), the protein expression and nuclear localization of p21 were reduced. After induction with EGF, p21 translocated to the cytoplasm in the control, whereas in the GHTD patient it remained located in the nucleus. Conclusion: In the GHTD fibroblasts, when CIS is reduced, either after siCIS or after a higher dose of hGH (GH1000), p21's antiproliferative effect (nuclear localization) is also reduced and GH signaling is activated. There also appears to be a positive relationship between the 2 inhibitors of GH signaling, CIS and p21. Finally, in GHTD, p21 seems to participate in the regulation of both the GH and EGF/EGFR pathways, depending upon its cellular location.

• Journal of Microbiology and Biotechnology
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• v.14 no.6
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• pp.1239-1248
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• 2004

The methylotrophic yeast Hansenula polymorpha has been extensively studied as a model organism for methanol metabolism and peroxisome biogenesis. Recently, this yeast has also attracted attention as a promising host organism for recombinant protein production. Here, we describe the fabrication and evaluation of a DNA chip spotted with 382 open reading frames (ORFs) of H. polymorpha. Each ORF was PCR-amplified using gene-specific primer sets, of which the forward primers had 5'-aminolink. The PCR products were printed in duplicate onto the aldehyde-coated slide glasses to link only the coding strands to the surface of the slide via covalent coupling between amine and aldehyde groups. With the partial genome DNA chip, we compared efficiency of direct and indirect cDNA target labeling methods, and found that the indirect method, using fluorescent-labeled dendrimers, generated a higher hybridization signal-to-noise ratio than the direct method, using cDNA targets labeled by incorporation of fluorescence-labeled nucIeotides during reverse transcription. In addition, to assess the quality of this DNA chip, we analyzed the expression profiles of H. polymorpha cells grown on different carbon sources, such as glucose and methanol, and also those of cells treated with the superoxide­generating drug, menadione. The profiles obtained showed a high-level induction of a set of ORFs involved in methanol metabolism and oxidative stress response in the presence of methanol and menadione, respectively. The results demonstrate the sensitivity and reliability of our arrays to analyze global gene expression changes of H. polymorpha under defined environmental conditions.

• Nutrition Research and Practice
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• v.9 no.6
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• pp.599-605
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• 2015

BACKGROUND/OBJECTIVES: Citrus flavonoids have a variety of physiological properties such as anti-oxidant, anti-inflammation, anti-cancer, and anti-obesity. We investigated whether bioconversion of Citrus unshiu with cytolase (CU-C) ameliorates the anti-adipogenic effects by modulation of adipocyte differentiation and lipid metabolism in 3T3-L1 cells. MATERIALS/METHODS: Glycoside forms of Citrus unshiu (CU) were converted into aglycoside forms with cytolase treatment. Cell viability of CU and CU-C was measured at various concentrations in 3T3L-1 cells. The anti-adipogenic and lipolytic effects were examined using Oil red O staining and free glycerol assay, respectively. We performed real time-polymerase chain reaction and western immunoblotting assay to detect mRNA and protein expression of adipogenic transcription factors, respectively. RESULTS: Treatment with cytolase decreased flavanone rutinoside forms (narirutin and hesperidin) and instead, increased flavanone aglycoside forms (naringenin and hesperetin). During adipocyte differentiation, 3T3-L1 cells were treated with CU or CU-C at a dose of 0.5 mg/ml. Adipocyte differentiation was inhibited in CU-C group, but not in CU group. CU-C markedly suppressed the insulin-induced protein expression of CCAAT/enhancer-binding protein ${\alpha}$ ($C/EBP{\alpha}$) and peroxisome proliferator-activated receptor gamma ($PPAR{\gamma}$) as well as the mRNA levels of $CEBP{\alpha}$, $PPAR{\gamma}$, and sterol regulatory element binding protein 1c (SREBP1c). Both CU and CU-C groups significantly increased the adipolytic activity with the higher release of free glycerol than those of control group in differentiated 3T3-L1 adipocytes. CU-C is particularly superior in suppression of adipogenesis, whereas CU-C has similar effect to CU on stimulation of lipolysis. CONCLUSIONS: These results suggest that bioconversion of Citrus unshiu peel extracts with cytolase enhances aglycoside flavonoids and improves the anti-adipogenic metabolism via both inhibition of key adipogenic transcription factors and induction of adipolytic activity.

• Journal of Life Science
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• v.18 no.11
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• pp.1485-1492
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• 2008

Prostaglandin $A_2$ ($PGA_2$), one of cyclopentenone PGs, induced both apoptosis and heme oxygenase (HO)-1 expression in U2OS cells. $PGA_2$-induced apoptosis was not perturbed by either over-expression or knock-down of HO-1, whereas $H_2O_2$-induced cell death was inversely modulated by the expression level of HO-1. In addition, N-acetyl-L-cysteine (NAC), a thiol antioxidant, blocked both apoptosis and HO-1 expression induced by $PGA_2$. But, non-thiol antioxidants like butylated hydorxyanisole (BHA) and ascorbic acid did not block either apoptosis or HO-1-induction. Taken together, these results suggest that $PGA_2$ induces both apoptosis and HO-1 expression, which are critically related to the thiol- reactivity of $PGA_2$, but not oxidative stress, and HO-1 expression may be independent or functionally located downstream of apoptosis by $PGA_2$ without contribution to apoptosis progression.

• KSBB Journal
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• v.29 no.1
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• pp.58-66
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• 2014

Demand for in vitro pharmacological evaluation and toxicity test using human hepatocytes has been increasing. In USA and Europe, human hepatocytes obtained from donated whole liver unsuitable for transplantation were distributed to researchers and deposited in cell bank facility as cryopreserved vial. In Korea, however, incidence of transplantation- inappropriate whole liver has been quite low and the whole livers almost have so severe liver disease such as fatty or fibrotic liver that cannot meet the demand. In this study we aimed to isolate human hepatocytes from liver resection surgery-originated partial liver, and assure the isolated human hepatocytes and its cryopreserved hepatocytes to be qualified for the in vitro pharmacological evaluation and drug toxicity tests. We compared those with commercially available human hepatocyte, BD $GenTest^{TM}$ by cell morphology, hepatic gene expression, urea synthesis, albumin secretion, ammonia removal, and cytochrome P450 induction activities. Changes in hepatotoxic gene expression after cryopreservation are evaluated with a typical hepatotoxic drug, acetaminophen. Consequently, the fresh hepatocytes from the partial liver and its cryopreserved hepatocytes expressed their intrinsic hepatic functions well and showed equal hepatotoxicity gene expression trend regardless to cryopreservation. Therefore, liver resection surgery-originated partial liver can be used as a useful source of human hepatocytes for various pharmacological and hepatotoxicity test.

• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.6
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• pp.527-537
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• 1991

To evaluate an effect of liver xanthine oxidase on the induction of liver damage, carbon tetrachloride (CCl4) was intraperitoneally injected twice at 0.1ml/100g body weight to the rate fed a low (LP)or high protein diet(HP) while the control group fed LP or HP received only olive oil. The changing rate of liver xanthine oxidas activity was compared with that of a free radical generating enzyme, liver aniline hydroxylase and a scavenging enzyme, glutathions S-transferase activity between the rate fed a LP and those fed HP, and the two groups treated with CCl4. Concomitantly, the degree of liver damage which could be considered as the paramete for CCl4 metabolism in case of CCl4-intoxicated animal was observed in the present experimental conditions and the effect of allopurinol, xanthine oxidase inhibitor, on the CCl4-toxicity of rate liver was alos demostrated. On the other hand, the comparative effect of actinomycin D on the liver and serum xanthine oxidase of CCl4-treated rats fed HP with that of those fed LP and the kinetics of purifed liver enzyme from the liver of CCl4-treated rats fed HP was also compared with that of those fed LP to clarify the differences of xanthine oxidase activity between two groups. The increasing rate of liver weigth/body wt, serum levels of ALT and the decreasing rate of hepatic ALT activity and protein contents to each control group were higher in CCl4-treated rats fed HP than those fed LP. Under the animal models as indentified by the present data herein, the liver xanthine oxidase activity was higher in CCl4-treated rats fed HP than those fed LP, and the control group fed HP also showed the much higher activity xanthine oxidase than that fed LP, whereas there were no differences in the activity of hepatic aniline hydroxylase and glutathions S-transferase between the two group treated with CCl4. Although the hepatic aniline hydroxylase activity was somewhat higher in the rats fed HP than those fed LP, the increasing rate of liver xanthine oxidase to the rats fed LP was higher in those fed HP than that of liver aniline hydroxylase. The degree of liver damage identified such as liver weight and serum ALT activity was less in the CCl4-treated rats pretreated with allopurinol. These results suggest that even a system at which xanthine oxidase acts as well as the drug metabolizing enzyme may influence the acelatin of CCl4 metabolism. In addition, the purified liver xanthine oxidase from CCl4-treated rats fed HP showed decreased Km value when compared to its control group. The Km value of liver xanthine oxidase of CCl4-treated rats fed LP showed a similar Km value with its control group. Furthermore, the decreasing rate of liver and serum xanthine oxidase acitivity in CCl4-treated rats pretreated with actinomycin D to the CCl4-treated rats was higher in rats fed HP than in those fed LP. These results suggest that the inductino of xanthine oxidase in CCl4-treated rats fed HP may be greater than in those fed LP.

• Radiation Oncology Journal
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• v.22 no.4
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• pp.298-306
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• 2004

Purpose: The purpose of this study was to identify Radiosensitivity of proteins in tissues with different radiosensitivity. Materials and Methods: C3H/HeJ mice were exposed to 10 Gy. The mice were sacrifiud 8 hrs after radiation. Their spleen and liver tissues were collected and analyzed histologicaly for apoptosis. The expressions of radiosusceptibillty protein were analyzed by 2-dimensional electrophoresis and matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Resilts: The Peak of apoptosis levels were $35.3{\pm}1.7{\%}$ in spleen and $0.6{\pm}0.2{\%}$ in liver at 8 hrs after radiation. Liver, radioresistant tissues, showed that the levels of ROS metabolism related to proteins such as cytochromm c, glutathione S transferase, NADH dehydrogenase, riken cDNA and peroxiredoxin Vl increased after radiation. The expression of cytochrome c increased significantly in spleen and liver tissues after radiation. In spleen, radiosensitivity tissue, the identified proteins showed a significantly quantitative alteration following radiation. It was categorized as signal transduction, apoptosis, cytokine, Ca signal related protein, stress-related protein, cytoskeletal regulation, ROS metabolism, and others. Conclusion: Differences of radiation-induced apoptosis by tissues specifted were coupled with the induction of related radiosensitivity and radioresistant proteins. The result suggests that apoptosis relate protein and redox proteins play important roles in this radiosusceptibility.

• Horticultural Science & Technology
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• v.19 no.1
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• pp.17-21
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• 2001

To develop a selection system for regenerating plants from transformed tissues, effects of four antibiotics (kanamycin, hygromycin, carbenicillin, cefotaxime) and herbicide (phosphinotricin) on shoot regeneration from cotyledon and hypocotyl explants of Chinese cabbage (Brassica campestris L. ssp. pekinensis) were studied. For cotyledon, shoot induction was not significantly affected by kanamycin at $1mg{\cdot}L^{-1}$, but the number of shoots formed was significantly reduced at $2mg{\cdot}L^{-1}$, and no shoots were regenerated from any explants at $6mg{\cdot}L^{-1}$ or higher. Hypocotyl explants showed similar result as cotyledon. Kanamycin at $7mg{\cdot}L^{-1}$ may be adequate for selecting Chinese cabbage transformants. Hygromycin at $4mg{\cdot}L^{-1}$ or higher completely inhibited the growth and shoot regeneration of Chinese cabbage explants. Therefore, resistance gene to hygromycin may also be used as a selective marker for Chinese cabbage transformation. Carbenicillin and cefotaxime, the cephalosporin type of antibiotics, had little effect on shoot regeneration of Chinese cabbage explants. Since carbenicillin and cefotaxime have low toxicity to Chinese cabbage, they are suitable for use in tissue culture to eliminate Agrobacterium in transformation experiments after co-cultivation. Shoot regeneration from cotyledon and hypocotyl explants was significantly reduced in presence of $1mg{\cdot}L^{-1}$ phosphinotricin (PPT) and completely inhibited by $2mg{\cdot}L^{-1}$ or higher. PPT, same as antibiotics, may also be used to select transformed cells. Since Chinese cabbage is known to be recalcitrant to in vitro shoot regeneration compared to other Brassica species, even though lower levels of selectable markers result in more transformants but simultaneously allow more untransformed escapes to develop, lower levels of antibiotics and herbicides could be successfully used as a selectable marker to reduce selection pressure.