• Genomics & Informatics
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• v.21 no.3
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• pp.41.1-41.11
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• 2023

The Dengue virus M protein is a 75 amino acid polypeptide with two helical transmembranes (TM). The TM domain oligomerizes to form an ion channel, facilitating viral release from the host cells. The M protein has a critical role in the virus entry and life cycle, making it a potent drug target. The oligomerization of the monomeric protein was studied using ab initio modeling and molecular dynamics simulation in an implicit membrane environment. The representative structures obtained showed pentamer as the most stable oligomeric state, resembling an ion channel. Glutamic acid, threonine, serine, tryptophan, alanine, isoleucine form the pore-lining residues of the pentameric channel, conferring an overall negative charge to the channel with approximate length of 51.9 Å. Residue interaction analysis for M protein shows that Ala94, Leu95, Ser112, Glu124, and Phe155 are the central hub residues representing the physicochemical interactions between domains. The virtual screening with 165 different ion channel inhibitors from the ion channel library shows monovalent ion channel blockers, namely lumacaftor, glipizide, gliquidone, glisoxepide, and azelnidipine to be the inhibitors with high docking scores. Understanding the three-dimensional structure of M protein will help design therapeutics and vaccines for Dengue infection.

• Journal of Pharmaceutical Investigation
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• v.41 no.5
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• pp.289-294
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• 2011

A rapid and specific high performance liquid chromatography-tandem mass (LC/MS/MS) method for the analysis of montelukast in human plasma has been developed and validated. After cold acetonitrile-induced precipitation of the plasma samples, montelukast and glipizide (internal standard, IS) were eluted on a reverse-phase $C_{18}$ column by isocratic mobile phase consisted of 10 mM ammonium formate buffer (adjusted to pH 3.5 with formic acid) and acetonitrile (3:97, v/v). Acquisition was performed with multiple reaction monitoring (MRM) mode by monitoring the transitions: m/z 587.2${\rightarrow}$ 423.2 for montelukast and m/z 446.0${\rightarrow}$321.2 for IS. Ranges of concentration for calibration curves (10-1000 ng/mL) showed correlation coefficients ($r^2$) were better than 0.9948. Precision of intra- and inter-day ranged from 3.70 to 11.68% and from 3.04 to 12.95%, accuracy of intra-day and inter-day ranged from 93.34 to 102.75% and from 100.79 to 107.63%, respectively. The described method provides a fast and sensitive analytical tool for determining montelukast levels in plasma, and was successfully applied to a pharmacokinetic study in 16 healthy human subjects after oral administration of 10mg tablet formulation of montelukast sodium under fasting conditions.

• Korean Journal of Clinical Pharmacy
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• v.28 no.3
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• pp.188-193
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• 2018

Background: Previous studies have noted that the simultaneous use of sulfonylureas and antimicrobials, which is common, could increase the risk of hypoglycemia. In particular, an age of 65 years or older is a known risk factor for sulfonylurea-related hypoglycemia in hospitalized patients. Therefore, we performed this study to determine the potential risk of hypoglycemia from the concurrent use of antimicrobials and sulfonylureas. Methods: We performed a cross-sectional study on the National Health Insurance Service-National Sample Cohort from 2013. The eligibility criteria included patients of 65 years of age or older taking a sulfonylurea with 25 different antimicrobials. Different risk ratings of severity in drug-drug interactions (potential DDIs), level X, D, or C in Lexi-$Interact^{TM}$ online, and contraindicated, major, or moderate severity level in $Micromedex^{(R)}$ were included. SAS version 9.4 was used for data analysis. Results: A total of 6,006 elderly patients with 25,613 prescriptions were included. The largest age group was 70 to 74 (32.7%), and 39.7% of patients were men. The mean number of prescriptions was 4.3 per patient. The most frequently used antimicrobials were levofloxacin (6,583, 25.7%), ofloxacin (6,549, 25.6%), fluconazole (4,678, 18.0%), and ciprofloxacin (2,551, 9.8%). Among sulfonylureas, glimepiride was prescribed most frequently, followed by gliclazide, glibenclamide, and glipizide. Conclusion: Of the antimicrobials with a high potential of hypoglycemia, levofloxacin, ofloxacin, fluconazole, and ciprofloxacin were used frequently. Thus, the monitoring of clinically relevant interactions is required for patients concurrently administered sulfonylureas and antimicrobials.

• Animal cells and systems
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• v.1 no.1
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• pp.81-86
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• 1997

We studied the mechanism of arachidonic acid on the secretion of a neurotransmitter in rat pheochromocytoma PC12 cells. Arachidonic acid inhibited the 70 mM $K^+$-induced secretion of norepinephrine. Arachidonic acid also inhibited the 70 mM $K^+$-induced $Ca^{2+}$ mobilization which is due to the opening of the voltage-sensitive $Ca^{2+}$ channels (VSCC). Both the half maximal inhibitory concentration ($IC_{50}$) of the norepinephrine secretion and VSCC coincided at 30 uM. The major oxidized metabolites of arachidonic acid, prostaglandins did not mimic the inhibitory effect of arachidonic acid. Nordihydroguaiaretic acid (NDGA) and indomethacin which are inhibitors of lipoxygenase and cyclooxygenase, respectively, did not block the inhibitory effect of arachidonic acid. The results suggest that arachidonic acid serves as a signal itself, not in the form of metabolites. The pretreatment of various $K^+$ channel blockers such as 4-aminopyridine, tetraethylarnmonium, glipizide, or glibenclamide also did not show any effect on the inhibitory effect of arachidonic acid. Through these results we suggest that arachidonic acid regulates VSCC directly and affects the secretion of neurotransmitters.

• The Korean Journal of Physiology and Pharmacology
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• v.19 no.3
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• pp.197-202
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• 2015

Sulfonylureas are widely used as an antidiabetic drug. In the present study, the effects of sulfonylurea administered supraspinally on immobilization stress-induced blood glucose level were studied in ICR mice. Mice were once enforced into immobilization stress for 30 min and returned to the cage. The blood glucose level was measured 30, 60, and 120 min after immobilization stress initiation. We found that intracerebroventricular (i.c.v.) injection with $30{\mu}g$ of glyburide, glipizide, glimepiride or tolazamide attenuated the increased blood glucose level induced by immobilization stress. Immobilization stress causes an elevation of the blood corticosterone and insulin levels. Sulfonylureas pretreated i.c.v. caused a further elevation of the blood corticosterone level when mice were forced into the stress. In addition, sulfonylureas pretreated i.c.v. alone caused an elevation of the plasma insulin level. Furthermore, immobilization stress-induced insulin level was reduced by i.c.v. pretreated sulfonylureas. Our results suggest that lowering effect of sulfonylureas administered supraspinally against immobilization stress-induced increase of the blood glucose level appears to be primarily mediated via elevation of the plasma insulin level.

• YAKHAK HOEJI
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• v.52 no.5
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• pp.345-354
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• 2008

This study was designed to investigate the anti-diabetic effect and mechanism of Korean red ginseng extract through transcriptomics in C57BL/KsJ db/db mice. The db/db mice were randomly divided into six groups: diabetic control group (DC), red ginseng extract low dose group (RGL, 100 mg/kg), red ginseng extract high dose group (RGH, 200 mg/kg), metformin group (MET, 300 mg/kg), glipizide group (GPZ, 15 mg/kg) and pioglitazone group (PIO, 30 mg/kg), and treated with drugs once per day for 10 weeks. At the end of treatment, we measured blood glucose, insulin, hemoglobin A1c (HbA1c), triglyceride (TG), adiponectin, leptin, non-esterified fatty acid (NEFA). RGL-treated group lowered the blood glucose and HbA1c levels by 19.6% and 11.4% compared to those in diabetic control group. In addition, plasma adiponectin and leptin levels in RGL-treated groups were increased by 20% and 12%, respectively, compared to those in diabetic control. Morphological analyses of liver, pancreas and epidydimal adipose tissue were done by hematoxylin-eosin staining, and pancreatic islet insulin and glucagon levels were detected by double-immunofluorescence staining. RGL-treated group revealed higher insulin contents and lower glucagon contents compared to diabetic control. To elucidate an action mechanism of Korean red ginseng, DNA microarray analyses were performed in liver and fat tissues, and western blot and RT-PCR were conducted in liver for validation. According to hierarchical clustering and principal component analysis of gene expression Korean red ginseng treated groups were close to metformin treated group. In summary, Korean red ginseng lowered the blood glucose level through protecting destruction of islet cells and shifting glucose metabolism from hepatic glucose production to glucose utilization and improving insulin sensitivity through enhancing plasma adiponectin and leptin levels.

• Journal of Acupuncture Research
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• v.25 no.2
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• pp.11-26
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• 2008

목적 : 홍삼약침(藥鍼)이 고혈당 및 지질대사장애에 미치는 개선효과와 그 기전을 조사하고자 한다. 방법 : 홍삼약침(藥鍼)의 anti-diabetic 활성과 그 기전을 C57BL/KsJ db/db mice를 이용하여 관찰하였다. 실험 동물은 대조군(DC), 홍삼약침(藥鍼)군(RGL, RGH) 및 양성대조군(MET, GPZ, PIO)의 6군으로 나누었다. 홍삼약침(藥鍼)군은 $0.2m{\ell}$의 홍삼약침멸(藥鍼滅)을 각각 100mg/kg(RGL) 및 200mg/kg(RGH)씩 인체의 간유(肝兪)($BL_{18}$)에 상응하는 혈위에 1일 1회 10주간 좌우 혈을 번갈아가며 약침 시술하였다. 양성대조군은 metformin 300mg/kg(MET), glipizide 15mg/kg(GPZ) 및 pioglitazone 30mg/kg(PIO)을 각각 1일 1회 10주간 경구투여 하였다. 체중과 혈당은 매주 측정하였다. 실험 10주 후에는 혈액채취로 혈중 glucose, 당화혈색소(HbAlc), insulin, 중성지방(TG), adiponectin, leptin, non-esterified fatty acid(NEFA)를 측정 하였고, 간 조직을 채취하여 조직학적 검사 및 gene expression 분석을 시행하였다. 결과 : 홍삼약침(藥鍼)(RGL, RGH)은 10주 동안 C57BL/KsJ db/db mice의 체중을 증가시키는 부작용은 나타나지 않았다. 홍삼약침(藥鍼)군(RGL, RGH)의 사료섭취량은 대조군과 비슷하였으나 음수량은 증가하였다. 홍삼약침(藥鍼)(RGL, RGH)은 대조군에 비하여 각각 19.8% 및 18.3% 혈당을 낮추었고, 홍삼약침(藥鍼)(RGL)은 insulin resistance를 27.7% 감소시켰으며, 경구내당능 검사의 혈중 glucose에서는 대조군에 비해 홍삼약침(藥鍼)군(RGL, RGH)과 양성대조군(MET, GPZ, PIO)에서 각각 19.8%, 18.3%, 67.7%, 52.3% 및 56.9% 감소시켰다. 당화혈색소(HbAlc)는 홍삼약침(藥鍼)(RGL, RGH), MET, GPZ 및 PIO군에서 대조군에 비하여 각각 11.0%, 6.4%, 18.9%, 16.1% 및 27.9% 감소시켰으며, 혈중 glucose감소와 유사한 경향을 나타내었다. 홍삼약침(藥鍼)(RGL)은 대조군에 비해 TG와 NEFA를 각각 18.8% 및 16.8% 감소시켰고, adiponectin과 leptin을 각각 20.6% 및 12.1% 증가시켰다. 홍삼약침(藥鍼)(RGL, RGH)은 중성지방의 침착으로 인한 간의 질량비 증가를 억제하지 못하였으나, 지방구를 감소시겼음을 관찰할 수 있었다. Microarray 분석에서는 홍삼약침(藥鍼)(RGL, RGH)이 간에서 glycolysis, gluconeogenesis 및 fatty acid beta-oxidation과 관련된 유전자 발현에 영향을 미치는 것으로 나타나 양성대조군 metformin과 유사한 기전을 나타내었다. 요약 : 홍삼약침(藥鍼)은 T2DM동물모델(C57BL/KsJ db/db mice)에서 항당뇨 및 지질대사 개선활성이 있었다. 홍삼약침(藥鍼)은 C57BL/KsJ db/db mice의 간조직에서 lipogenesis억제 및 fatty acid beta-oxidation활성을 통해 혈당 이용을 높이고, insulin sensitivity를 향상시켰다. 또한 유전자 발현분석을 통해 그 기전이 metformin과 유사함을 확인할 수 있었으므로 향후 홍삼약침(藥鍼)의 새로운 약침 기술 개발 근거가 될 수 있을 것으로 사료된다.

• Proceedings of the Ginseng society Conference
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• 2007.12a
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• pp.57-58
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• 2007

Purpose: Ginseng is a well-known medical plant used in traditional Oriental medicine. Korean red ginseng (KRG) has been known to have potent biological activities such as radical scavenging, vasodilating, anti-tumor and anti-diabetic activities. However, the mechanism of the beneficial effects of KRG on diabetes is yet to be elucidated. The present study was designed to investigate the anti-diabetic effect and mechanism of KRG extract in C57BL/KsJ db/db mice. Methods: The db/db mice were randomly divided into six groups: diabetic control group (DC), red ginseng extract low dose group (RGL, 100 mg/kg), red ginseng extract high dose group (RGH, 200 mg/kg), metformin group (MET, 300 mg/kg), glipizide group (GPZ, 15 mg/kg) and pioglitazone group (PIO, 30 mg/kg), and treated with drugs once per day for 10 weeks. During the experiment, body weight and blood glucose levels were measured once every week. At the end of treatment, we measured Hemoglobin A1c (HbA1c), blood glucose, insulin, triglyceride (TG), adiponectin, leptin, non-esterified fatty acid (NEFA). Morphological analyses of liver, pancreas and white adipose tissue were done by histological observation through hematoxylin-eosin staining. Pancreatic islet insulin and glucagon levels were detected by double-immunofluorescence staining. To elucidate an action of mechanism of KRG, DNA microarray analyses were performed, and western blot and RT-PCR were conducted for validation. Results: Compared to the DC group mice, body weight gain of PIO treated group mice showed 15.2% increase, but the other group mice did not showed significant differences. Compared to the DC group, fasting blood glucose levels were decreased by 19.8% in RGL, 18.3% in RGH, 67.7% in MET, 52.3% in GPZ, 56.9% in PIO-treated group. With decreased plasma glucose levels, the insulin resistance index of the RGL-treated group was reduced by 27.7% compared to the DC group. Insulin resistance values for positive drugs were all markedly decreased by 80.8%, 41.1% and 68.9%, compared to that of DC group. HbA1c levels in RGL, RGH, MET, GPZ and PIO-treated groups were also decreased by 11.0%, 6.4%, 18.9%, 16.1% and 27.9% compared to that of DC group, and these figure revealed a similar trend shown in plasma glucose levels. Plasma TG and NEFA levels were decreased by 18.8% and 16.8%, respectively, and plasma adiponectin and leptin levels were increased by 20.6% and 12.1%, respectively, in the RGL-treated group compared to those in DC group. Histological analysis of the liver of mice treated with KRG revealed a significantly decreased number of lipid droplets compared to the DC group. The control mice exhibited definitive loss and degeneration of islet, whereas mice treated with KRG preserved islet architecture. Compared to the DC group mice, KRG resulted in significant reduction of adipocytes. From the pancreatic islet double-immunofluorescence staining, we observed KRG has increased insulin production, but decreased glucagon production. KRG treatment resulted in stimulation of AMP-activated protein kinase (AMPK) phosphorylation in the db/db mice liver. To elucidate mechanism of action of KRG extract, microarray analysis was conducted in the liver tissue of mice treated with KRG extract, and results suggest that red ginseng affects on hepatic expression of genes responsible for glycolysis, gluconeogenesis and fatty acid oxidation. In summary, multiple administration of KRG showed the hypoglycemic activity and improved glucose tolerance. In addition, KRG increased glucose utilization and improved insulin sensitivity through inhibition of lipogenesis and activation of fatty acid $\beta$-oxidation in the liver tissue. In view of our present data, we may suggest that KRG could provide a solid basis for the development of new anti-diabetic drug.