• Journal of Veterinary Science
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• v.23 no.1
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• pp.4.1-4.15
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• 2022

Background: Flavonoids are natural polyphenols found widely in citrus fruit and peel that possess anti-adipogenic effects. On the other hand, the detailed mechanisms for the antiadipogenic effects of flavonoids are unclear. Objectives: The present study observed the anti-adipogenic effects of five major citrus flavonoids, including hesperidin (HES), narirutin (NAR), nobiletin (NOB), sinensetin (SIN), and tangeretin (TAN), on AMP-activated protein kinase (AMPK) activation in palmitate (PA)-treated HepG2 cells. Methods: The intracellular lipid accumulation and triglyceride (TG) contents were quantified by Oil-red O staining and TG assay, respectively. The glucose uptake was assessed using 2-[N-(7-Nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxy-d-glucose (2-NBDG) assay. The levels of AMPK, acetyl-CoA carboxylase (ACC), and glycogen synthase kinase 3 beta (GSK3β) phosphorylation, and levels of sterol regulatory element-binding protein 2 (SREBP-2) and 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) expression were analyzed by Western blot analysis. The potential interaction between the flavonoids and the γ-subunit of AMPK was investigated by molecular docking analysis. Results: The flavonoid treatment reduced both intracellular lipid accumulation and TG content in PA-treated HepG2 cells significantly. In addition, the flavonoids showed increased 2-NBDG uptake in an insulin-independent manner in PA-treated HepG2 cells. The flavonoids increased the AMPK, ACC, and GSK3β phosphorylation levels and decreased the SREBP-2 and HMGCR expression levels in PA-treated HepG2 cells. Molecular docking analysis showed that the flavonoids bind to the CBS domains in the regulatory γ-subunit of AMPK with high binding affinities and could serve as potential AMPK activators. Conclusion: The overall results suggest that the anti-adipogenic effect of flavonoids on PA-treated HepG2 cells results from the activation of AMPK by flavonoids.

• Bulletin of the Korean Chemical Society
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• v.34 no.4
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• pp.1212-1220
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• 2013

The human coagulation factor XI (FXI) is a serine protease that plays a significant role in blocking of the blood coagulation cascade as an attractive antithrombotic target. Selective inhibition of FXIa (an activated form of factor XI) disrupts the intrinsic coagulation pathway without affecting the extrinsic pathway or other coagulation factors such as FXa, FIIa, FVIIa. Furthermore, targeting the FXIa might significantly reduce the bleeding side effects and improve the safety index. This paper reports on a docking-based three dimensional quantitative structure activity relationship (3D-QSAR) study of the potent FXIa inhibitors, the chloro-phenyl tetrazole scaffold series, using comparative molecular field analysis (CoMFA) and comparative molecular similarity analysis (CoMSIA) methods. Due to the characterization of FXIa binding site, we classified the alignment of the known FXIa inhibitors into two groups according to the docked pose: S1-S2-S4 and S1-S1'-S2'. Consequently, highly predictive 3D-QSAR models of our result will provide insight for designing new potent FXIa inhibitors.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.8
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• pp.4019-4023
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• 2016

Background: Colorectal cancer (CRC) or bowel cancer is one of the most important cancer diseases, needing serious attention. The cell surface receptor gene human epidermal growth factor receptor (EGFR) may have an important role in provoking CRC. In this pharmaceutical era, it is always attempted to identify plant-based drugs for cancer, which will have less side effects for human body, unlike the chemically synthesized marketed drugs having serious side effects. So, in this study the authors tried to assess the activity of two important plant compounds, ferulic acid (FA) and p-coumaric acid (pCA), on CRC. Materials and Methods: FA and pCA were tested for their cytotoxic effects on the human CRC cell line HCT 15 and also checked for the level of gene expression of EGFR by real time PCR analysis. Positive results were confirmed by in silico molecular docking studies using Discovery Studio (DS) 4.0. The drug parallel features of the same compounds were also assessed in silico. Results: Cytotoxicity experiments revealed that both the compounds were efficient in killing CRC cells on a controlled concentration basis. In addition, EGFR expression was down-regulated in the presence of the compounds. Docking studies unveiled that both the compounds were able to inhibit EGFR at its active site. Pharmacokinetic analysis of these compounds opened up their drug like behaviour. Conclusions: The findings of this study emphasize the importance of plant compounds for targeting diseases like CRC.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.13
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• pp.5311-5317
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• 2015

Cigarette smoke derivatives like NNK (4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone) and NNAL (4-(methylnitrosamino)-1-(3-pyridyl)-1-butan-1-ol) are well-known carcinogens. We analyzed the interaction of enzymes involved in the NER (nucleotide excision repair) pathway with ligands (NNK and NNAL). Binding was characterized for the enzymes sharing equivalent or better interaction as compared to +Ve control. The highest obtained docking energy between NNK and enzymes RAD23A, CCNH, CDK7, and CETN2 were -7.13 kcal/mol, -7.27 kcal/mol, -8.05 kcal/mol and -7.58 kcal/mol respectively. Similarly the highest obtained docking energy between NNAL and enzymes RAD23A, CCNH, CDK7, and CETN2 were -7.46 kcal/mol, -7.94 kcal/mol, -7.83 kcal/mol and -7.67 kcal/mol respectively. In order to find out the effect of NNK and NNAL on enzymes involved in the NER pathway applying protein-protein interaction and protein-complex (i.e. enzymes docked with NNK/NNAL) interaction analysis. It was found that carcinogens are well capable to reduce the normal functioning of genes like RAD23A (HR23A), CCNH, CDK7 and CETN2. In silico analysis indicated loss of functions of these genes and their corresponding enzymes, which possibly might be a cause for alteration of DNA repair pathways leading to damage buildup and finally contributing to cancer formation.

• Natural Product Sciences
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• v.27 no.2
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• pp.99-114
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• 2021

Type 2 diabetes mellitus (T2DM) and its complications are important noncommunicable diseases with high mortality rates. Protein tyrosine phosphatase 1B (PTP1B) and aldose reductase inhibitors are recently approached and advanced for T2DM and its complications therapy. Matricaria chamomilla L. is acknowledged as a worldwide medicinal herb that has many beneficial health effects as well as antidiabetic effects. Our research was designed to determine the most potential antidiabetic phytochemicals from M. chamomilla employing in silico study. 142 phytochemicals were obtained from the databases. The first screening employed iGEMdock and Swiss ADME, involving 93 phytochemicals. Finally, 30 best phytochemicals were docked. Molecular docking and visualization analysis were performed using Avogadro, AutoDock 4.2., and Biovia Discovery Studio 2016. Molecular docking results demonstrate that ligand-protein interaction's binding affinities were -5.16 to -7.54 kcal/mol and -5.30 to -12.10 kcal/mol for PTP1B and aldose reductase protein targets respectively. In silico results demonstrate that M. chamomilla has potential antidiabetic phytochemical compounds for T2DM and its complications. We recommended anthecotulide, quercetin, chlorogenic acid, luteolin, and catechin as antidiabetic agents due to their binding affinities against both PTP1B and aldose reductase protein. Those phytochemicals' significant efficacy and potential as antidiabetic must be investigated in further advanced research.

• Journal of Veterinary Science
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• v.22 no.6
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• pp.92.1-92.12
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• 2021

Background: Naringin and its aglycone naringenin are citrus-derived flavonoids with several pharmacological effects. On the other hand, the mechanism for the anti-diabetic effects of naringenin and naringin are controversial and remain to be clarified further. Objective: This study examined the relationship between glucose uptake and AMP-activated protein kinase (AMPK) phosphorylation by naringenin and naringin in high glucose-treated HepG2 cells. Methods: Glucose uptake was measured using the 2-NBDG fluorescent D-glucose analog. The phosphorylation levels of AMPK and GSK3β (Glycogen synthase kinase 3 beta) were observed by Western blotting. Molecular docking analysis was performed to evaluate the binding affinity of naringenin and naringin to the γ-subunit of AMPK. Results: The treatment with naringenin and naringin stimulated glucose uptake regardless of insulin stimulation in high glucose-treated HepG2 cells. Both flavonoids increased glucose uptake by promoting the phosphorylation of AMPK at Thr172 and increased the phosphorylation of GSK3β. Molecular docking analysis showed that both naringenin and naringin bind to the γ-subunit of AMPK with high binding affinities. In particular, naringin showed higher binding affinity than the true modulator, AMP with all three CBS domains (CBS1, 3, and 4) in the γ-subunit of AMPK. Therefore, both naringenin and naringin could be positive modulators of AMPK activation, which enhance glucose uptake regardless of insulin stimulation in high glucose-treated HepG2 cells. Conclusions: The increased phosphorylation of AMPK at Thr172 by naringenin and naringin might enhance glucose uptake regardless of insulin stimulation in high glucose treated HepG2 cells.

• Journal of Integrative Natural Science
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• v.10 no.2
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• pp.74-77
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• 2017

Bradykinin receptor B2 (B2R) is a GPCR protein which binds with the inflammatory mediator hormone bradkynin. Kallidin, a decapeptide, also signals through this receptor. B2R is crucial in the cross-talk between renin-angiotensin system (RAS) and the kinin-kallikrein system (KKS) and in many processes including vasodilation, edema, smooth muscle spasm and pain fiber stimulation. Thus the structural study of the receptor becomes important. We have predicted the peptide structures of Bradykinin and Kallidin from their amino acid sequences and the structures were docked with the receptor structure. The results obtained from protein-protein docking could be helpful in studying the B2R structural features and in the pathophysiology in various diseases related to it.

• Journal of Integrative Natural Science
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• v.10 no.3
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• pp.125-130
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• 2017

Glucagon like pepide-2, one of the GLPs, is involved in various metabolic functions in the gastrointestinal tract. It plays a major role in the regulation of mucosal epithelium and the intestinal crypt cell proliferation. Because of their therapeutic importance towards the diseases in the gastrointestinal tract, it becomes necessary to study their interaction with its receptor, GLP-2R. In this study, we have developed protein-protein docking complexes of GLP-2 - GLP-2 receptor. Homology models of GLP-2 are developed, and a reliable model out of the predicted models was selected after model validation. The model was bound with the receptor, to study the important interactions of the complex. This study could be useful in developing novel and potent drugs for the diseases related with GLP-2.

• Journal of Integrative Natural Science
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• v.5 no.1
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• pp.18-21
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• 2012

The resistance of tumour cells against cytotoxic drug is significant limitation in successful chemotherapeutic treatment of cancer. To date, no crystal structure is available for human P-gp. We developed homology model for human P-gp NBD2 by using coordinates of transporter associated protein (TAP1). Docking study was performed for 8-geranyl-chrysin (Flavonoids) inhibitor in the NBD2 model. Ligand-protein interactions were determined which indicates that the 8-geranyl chrysin shares two overlapping sites in the cytosolic domains of P-gp, the ATP site and a hydrophobic steroid-binding site.