• Title/Summary/Keyword: Enzyme model

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Lamotrigine Decreased Hippocampal Damage and Improved Vascular Risk Markers in a Rat Model of Pentylenetetrazole Induced Kindling Seizure

  • Haggag, Basma S.;Hasanin, Amany H.;Raafat, Mona H.;Kawy, Hala S. Abdel
    • The Korean Journal of Physiology and Pharmacology
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    • v.18 no.3
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    • pp.269-278
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    • 2014
  • Various antiepileptic drugs (AEDs) especially enzyme-inducing AEDs might be associated with increased vascular risk, through impairment of the endogenous antioxidative ability which may trigger oxygen-dependent tissue injury. Lamotrigine (LTG) a non-enzyme-inducing AED has scarce information regarding its effects on oxidative stress. The present study aimed to study the possible modulation of vascular risk factors of epileptogenesis by LTG, in a rat model of kindling seizure induced by pentylenetetrazole (PTZ). Four groups of male Wister rats were used; vehicle control group, PTZ group (alternate day PTZ, 30 mg/kg, i.p), LTG/PTZ group (LTG 20 mg/kg/day p.o and alternate day PTZ) and LTG group. The study period was 5 weeks. Lipoproteins and total homocysteine (tHcy), malondialdehyde (MDA) and reduced glutathione (GSH) were measured. Aortic endothelial function study and histopathological examination of the rats' brains, aortas and coronaries were conducted. Serum total cholesterol (TC), triglyceride (TG) and low-density lipoprotein cholesterol (LDL-C), tHcy, MDA, GSH levels were significantly higher in epileptic rats than normal controls rats. A decrease in HDL-cholesterol with high atherosclerotic index was also demonstrated. The administration of LTG improved the PTZ-kindled seizures. It produced a significant decrease in TC, TG and LDL-cholesterol, MDA, aortic GSH and increase in HDL-cholesterol with no significant effect on serum GSH and tHcy levels. LTG improved endothelium-dependent relaxation, decreased hippocampal neurodegenerative changes and atherosclerotic changes of aortas and coronaries. LTG decreased seizures severity, hippocampal damage and improved vascular risk markers in this rat model of kindling seizures.

Effects of Samiunkyungtang on inflammation and fecal enzymes in ulcerative colitis animal model (궤양성 대장염 동물모델에서 사미연견탕(四味軟堅湯)의 항염증 및 장내세균 효소활성 억제효과)

  • Kim, So-Yeon;Ryu, Bong-Ha;Park, Jae-Woo
    • The Journal of Korean Medicine
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    • v.29 no.3
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    • pp.50-62
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    • 2008
  • Objectives: This study was aimed to find the effect of Samiunkyungtang on inflammation and microflora in an ulcerative colitis animal model. Methods: We established four groups of normal, control, test 1, and test 2 and assigned 6 rats toeach group. The normal group was not treated by any process and fed by normal saline. The control & test groups were provided with 4% dextran sodium sulfate (DSS) treatment for 7 days. Samiunkyungtang extract was orally administered to test groups (test 1=25mg/kg, test 2 100mg/kg) 3 days after DSS treatment for 10 days. After DSS treatment finished, we sacrificed the mice and measured colon length and enzyme activities such as myeloperoxidase (MPO), alkine phosphatase (ALP), ${\beta}$-glucuronidase, ${\beta}$-glucosidase, chondroitinase, and tryptophanase. Results: The colon lengths of test 1 and 2 groups were longer than the control group (p<0.05). Histologically, the crypts and superficial epitheliums of test 1 and 2 groups were regenerated. Goblet cells from all test groups were retrieved. The inflammatory biochemical marker, MPO and ALP activities in all test groups were highly reduced (p<0.01) compared to the control group. The activities of fecal bacterial enzymes in test groups such as ${\beta}$-glucuronidase, ${\beta}$-glucosidase, chondroitinase, and tryptophanase were reduced compared to the control group (p<0.01). Conclusions: As a result of this experiment, Samiunkyungtang is considered to have an inhibitory effect on inflammation and fecal enzyme activity in DSS-induced colitis animal model. Our results indicate that Samiunkyungtang may possess therapeutic effect on the development of DSS-induced colitis.

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Virtual Screening of Tubercular Acetohydroxy Acid Synthase Inhibitors through Analysis of Structural Models

  • Le, Dung Tien;Lee, Hyun-Sook;Chung, Young-Je;Yoon, Moon-Young;Choi, Jung-Do
    • Bulletin of the Korean Chemical Society
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    • v.28 no.6
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    • pp.947-952
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    • 2007
  • Mycobacterium tuberculosis is a pathogen responsible for 2-3 million deaths every year worldwide. The emergence of drug-resistant and multidrug-resistant tuberculosis has increased the need to identify new antituberculosis targets. Acetohydroxy acid synthase, (AHAS, EC 2.2.1.6), an enzyme involved in branched-chain amino acid synthesis, has recently been identified as a potential anti-tuberculosis target. To assist in the search for new inhibitors and “receptor-based” design of effective inhibitors of tubercular AHAS (TbAHAS), we constructed four different structural models of TbAHAS and used one of the models as a target for virtual screening of potential inhibitors. The quality of each model was assessed stereochemically by PROCHECK and found to be reliable. Up to 89% of the amino acid residues in the structural models were located in the most favored regions of the Ramachandran plot, which indicates that the conformation of each residue in the models is good. In the models, residues at the herbicide-binding site were highly conserved across 39 AHAS sequences. The binding mode of TbAHAS with a sulfonylurea herbicide was characterized by 32 hydrophobic interactions, the majority of which were contributed by residue Trp516. The model based on the highest resolution X-ray structure of yeast AHAS was used as the target for virtual screening of a chemical database containing 8300 molecules with a heterocyclic ring. We developed a short list of molecules that were predicted to bind with high scores to TbAHAS in a conformation similar to that of sulfonylurea derivatives. Five sulfonylurea herbicides that were calculated to efficiently bind TbAHAS were experimentally verified and found to inhibit enzyme activity at micromolar concentrations. The data suggest that this time-saving and costeffective computational approach can be used to discover new TbAHAS inhibitors. The list of chemicals studied in this work is supplied to facilitate independent experimental verification of the computational approach.

Preliminary Study on the Osteoporosis Improvement Effect of Compounds Isolated from Oryza sativa L. root Extract in the Ovariectomized Mouse Model (난소 적출 마우스 모델에서 Oryza sativa L.의 뿌리 추출물에서 분리된 화합물의 골다공증 개선 효과에 관한 예비연구)

  • Seon-Hee Kim;Eun-Yong Choi;Hee-Jin Yang;Jun Sang Bae
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.37 no.2
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    • pp.30-35
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    • 2023
  • Bisphosphonates, estrogen, and calcium supplements are commonly used medications for postmenopausal osteoporosis, but they are associated with various side effects such as vaginal bleeding, deep vein thromembolism, and breast cancer. In this study, we aimed to investigate the potential of a compound isolated from the roots of Oryza sativa L. to improve osteoporosis using an ovariectomized mouse model. We isolated and identified oryzativol A, a lignan compound, through chemical analysis of an ethanol extract using a bioassay-guided fractionation protocol. We also examined the metabolism, clearance, and CYP enzyme activity of oryzativol A, and found that it showed plasma stability of over 80% at all analysis times, and indicating a low likelihood of inactivation or excretion by the CYP3A4 enzyme. Our results showed that the high-dose group of oryzativol A exhibited a significant increase in bone mineral density compared to the control group. Although the ALP concentration did not differ significantly compared to the control group, it showed a tendency to increase in the high-dose group of oryzativol A. Furthermore, the abnormal ratio of serum Ca/P, caused by osteoporosis, was improved to a level closer to that of the normal group as the dosage of oryzativol A increased. Taken together, these findings suggest that oryzativol A is stable in vivo and has potential as a therapeutic agent for osteoporosis, particularly when administered in high doses.

Therapeutic effects of paeoniflorin on irritable bowel syndrome in rats

  • Lei Wang;Jinyan Lei;Zeyu Zhao;Jianwei Jia;Li Wang
    • Journal of Veterinary Science
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    • v.24 no.3
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    • pp.23.1-23.16
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    • 2023
  • Background: Irritable bowel syndrome (IBS) is a functional bowel disorder (FBD). Objectives: To assess the therapeutic effects of paeoniflorin (PF) on IBS in rats. Method: Sixty male Sprague-Dawley rats were randomly divided into normal, model, positive drug, low-dose PF, medium-dose PF and high-dose PF groups (n = 10). After gavage for 2 consecutive weeks, the effect of PF on abdominal pain symptoms was assessed based on the abdominal withdrawal reflex (AWR) score, fecal water content and pathological changes in colon tissues. D-lactate, interleukin-1β (IL-1β), transforming growth factor-β (TGF-β) and tumor necrosis factor-α (TNF-α) were detected by enzyme-linked immunosorbent assay, and phosphorylated nuclear factor kappa B (p-NF-κB) p65 was detected by Western blotting. The abundance and diversity changes of intestinal flora were explored using 16S ribosomal RNA sequencing. Result: In PF groups, the mucosal morphology of colon tissues was intact, and the glands were arranged neatly and structured clearly, without obvious inflammatory cell infiltration. Compared with the model group, PF groups had significantly elevated pain threshold, and mRNA and protein levels of zonula occludens-1 (ZO-1) and occludin, decreased AWR score at 20 mmHg pressure, fecal water content, mRNA levels of IL-1β, TGF-β, and TNF-α, protein level of p-NF-κB p65 and level of serum D-lactate, and reduced levels of serum IL-1β, TGF-β, and TNF-α (p < 0.05, p < 0.01). PF groups had higher abundance of Lactobacillus, Akkermansia, Alistipes, and Bacteroides, but lower abundance of Desulfovibrio, Parasutterella, and Enterococcus than those of the model group. Conclusions: PF exerts therapeutic effects on IBS in rats probably by regulating the intestinal flora, and then up-regulating the expressions of ZO-1 and occludin in colon tissue while down-regulating the levels of IL-1β, TGF-β, TNF-α, D-lactate and p-NF-κB p65.

Study of the Effect and Underlying Mechanism of Enzyme-Treated Garlic Extract on a Lipopolysaccharide-Induced Acute Colitis Model (효소처리를 이용한 마늘 추출물이 Lipopolysaccharide 유발 급성 장염 모델에 미치는 효과 및 기전 연구)

  • Min Ju Kim;Mi-Rae Shin;Hak Joo Choi;Seong-Soo Roh
    • The Journal of Internal Korean Medicine
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    • v.44 no.6
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    • pp.1243-1255
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    • 2023
  • Objective: This study aims to explore the pharmacological effects and mechanisms of enzyme (Viscozyme)-treated garlic extract (EG) in an animal model of acute enteritis induced by lipopolysaccharide (LPS). Methods: The experiment included four subgroups: normal, control, EG200 (treated with 200 mg/kg EG), and EG400 (treated with 400 mg/kg EG). Drug administration lasted 3 days, followed by the induction of acute enteritis in all groups (except normal) through the intraperitoneal administration of 20 mg/kg of LPS 1 h after the last oral dose. Autopsy was conducted 24 h later to collect serum and colon tissue. Serum was analyzed for reactive oxygen species (ROS) and C-reactive protein (CRP), while Western blotting was performed on the colon tissue. Results: After analyzing the ROS and CRP levels in serum, the EG treatment group exhibited a significant decrease compared with the control group. The EG treatment group exhibited a significant decrease in the activation of the mitogen-activated protein kinases (MAPKs)/nuclear factor-kappa B p65 (NF-κB) pathway compared with the control group. EG administration significantly regulated apoptosis-related factors, including B-cell lymphoma-2 (Bcl-2), Bcl-2-associated X, cysteine aspartyl-specific protease-3, and cytochrome C. Conclusions: EG treatment in mice with LPS-induced acute colitis reduced the ROS and CRP levels, suppressed the MAPKs/NF-κB pathway in the colon, and effectively alleviated acute enteritis by modulating apoptosis-related factors. Based on these findings, EG emerges as a promising candidate for the prevention and treatment of acute colitis, showing its potential therapeutic efficacy in this experimental model.

Hologram Based QSAR Analysis of Xanthine Oxidase Inhibitors

  • Sathya., B
    • Journal of Integrative Natural Science
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    • v.10 no.4
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    • pp.202-208
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    • 2017
  • Xanthine Oxidase is an enzyme, which oxidizes hypoxanthine to xanthine, and xanthine to uric acid. It is widely distributed throughout various organs including the liver, gut, lungs, kidney, heart, brain and plasma. It is involved in gout pathogenesis. Hence, in the present study, Hologram based Quantitative Structure Activity Relationship Study was performed on a series of Xanthine Oxidase antagonist named 2-(indol-5-yl) thiazole derivatives. The best HQSAR model was obtained using Atoms, Bonds, Connection, Hydrogen, Chirality and Donor Acceptor as fragment distinction parameter using hologram length 71 and 4 components with fragment size of minimum 2 and maximum 5. Significant cross-validated correlation coefficient ($q^2$= 0.563) and non cross-validated correlation coefficients ($r^2$= 0.967) were obtained. The model was then used to evaluate the six external test compounds and its $r^2{_{pred}}$ was found to be 0.798. Contribution map show that presence of propyl ring in indole thiazole makes big contributions for improving the biological activities of the compounds. We hope that our HQSAR model and analysis will be helpful for future design of xanthine oxidase antagonists.

Topomer CoMFA Analysis of Xanthine Oxidase inhibitors

  • Santhosh Kumar, N
    • Journal of Integrative Natural Science
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    • v.10 no.4
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    • pp.192-196
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    • 2017
  • Xanthine Oxidase is an enzyme, which oxidizes hypoxanthine to xanthine, and xanthine to uric acid. It is widely distributed throughout various organs including the liver, gut, lungs, kidney, heart, brain and plasma. It is involved in gout pathogenesis. Hence, in the present study, topomer based Comparative Molecular Field Analysis (topomer CoMFA) was performed on a series of Xanthine oxidase antagonist named 2-(indol-5-yl) thiazole derivatives. The best topomer CoMFA model was obtained with significant cross-validated correlation coefficient ($q^2$ = 0.572) and non cross-validated correlation coefficients ($r^2$ = 0.937). The model was evaluated with six external test compounds and its $r^2{_{pred}}$ was found to be 0.553. The steric and electrostatic contribution map show that presence of bulky and electropositive group in indole thiazole ring is necessary for improving the biological activities of the compounds. The generated topomer CoMFA model could be helpful for future design of novel and structurally related xanthine oxidase antagonists.

A Model for the Active Site of Cyclooxygenase (사이클로옥시게나제의 작용부위 모델)

  • Kim, Yang-Bae;Chung, Uoo-Tae;Park, Il-Yeong
    • Journal of Pharmaceutical Investigation
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    • v.26 no.3
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    • pp.155-168
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    • 1996
  • The active site of cyclooxygenase was modeled by complementary receptor-cavity mapping procedure using 3D structures of the non-steroidal antiinflammatory drugs (NSAIDs). A total of 50 NSAIDs were chosen as data ligands which compete the same site on the enzyme. Partial atomic charges were estimated, and the energetic differences for various conformations were calculated so as to meet the need for a most efficient overlapping of the probably-equivalent functional groups of the ligand molecules. The structure activity relationships of the NSAIDs, if available, were fully considered throughout the modeling. The overall shape of the model obtained is similar to a boot-without-bottom. Most of inner surface of the cavity appeared as hydrophobic; two polar counterparts except the carboxyl-binding position were found. By this model, some clear explanations could be given on the experimental observations which were not satisfiably understood yet.

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Effect of Lipoxygenase on the Oxidation of Rainbow Trout Lipid in Model system (모델시스템에 있어서 무지개 송어 지방질의 산화에 대한 Lipoxygenase의 영향)

  • 김혜경;엄수현;최홍식
    • Journal of Life Science
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    • v.5 no.2
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    • pp.70-75
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    • 1995
  • The effect of lipoxygenase (LOX) on the oxidation and co-oxidation of lipid fraction was studied in the model system of rainbow trout. For the reaction in model system 1 g of lipid fraction and 50mL of enzyme extract(LOX, 140 unit in 50mL phosphate buffer solution at pH 7, 4)), which were obtained from rainbow trout, were homoginized in the presence of Tween 20 and kept at 23$\circ$C for 3 days. The activity of LOX was decreased to 43% of initial level during the reaction in the model system. The initial composition of rainbow trout lipid was showed to be consisted of trigliceride(TG;82%) and free fatty acid(FFA;0.1%), while this converted to 59% of TG and 20% of FIFA, respectively after reaction in model system. Change of fatty acid composition was also observed and the content of linoleic acid, one of the major fatte acids, was decreased to 13% from 54% in the content of total fatty acids after reaction. The carotenoids in rainbow trout were composed of 0.4% $\alpha$-carotene, 1.6% $\beta$ -carotene, 80% canthaxanthin, 7% lutein and 11% zeaxanthin, thus the canthaxanthin was the major component. This canthaxanthin was the most degraded carotenoid by lipoxygenase catalyzed co-oxidation during the reaction. On the other hand the tocopherol isomers found in the rainbow trout were $\alpha$ and $\beta$ -tocopherol, and $\alpha$-tocopherol had a higher degradation rate by the lipoxygenase catalyzed co-oxidation than of $\beta$-tocopherol in the reaction of model system.

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