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O-GlcNAcylation is a nutrient-sensing post-translational modification process. This cycling process involves two primary proteins: the O-linked N-acetylglucosamine transferase (OGT) catalysing the addition, and the glycoside hydrolase OGA (O-GlcNAcase) catalysing the removal of the O-GlCNAc moiety on nucleocytoplasmic proteins. This process is necessary for various critical cellular functions. The O-linked N-acetylglucosamine transferase (OGT) gene produces the OGT protein. Several studies have shown the overexpression of this protein to have biological implications in metabolic diseases like cancer and diabetes mellitus (DM). This study retrieved 159 SNPs with clinical significance from the SNPs database. We probed the functional effects, stability profile, and evolutionary conservation of these to determine their fit for this research. We then identified 7 SNPs (G103R, N196K, Y228H, R250C, G341V, L367F, and C845S) with predicted deleterious effects across the four tools used (PhD-SNPs, SNPs&Go, PROVEAN, and PolyPhen2). Proceeding with this, we used ROBETTA, a homology modelling tool, to model the proteins with these point mutations and carried out a structural bioinformatics method- molecular docking- using the Glide model of the Schrodinger Maestro suite. We used a previously reported inhibitor of OGT, OSMI-1, as the ligand for these mutated protein models. As a result, very good binding affinities and interactions were observed between this ligand and the active site residues within 4Å of OGT. We conclude that these mutation points may be used for further downstream analysis as drug targets for treating diabetes mellitus.
Assuntos
Diabetes Mellitus , Mutação Puntual , Humanos , Simulação de Acoplamento Molecular , Ligantes , Mutação , Diabetes Mellitus/genética , Processamento de Proteína Pós-TraducionalRESUMO
Gγ7 is enriched in striatum and forms a heterotrimeric complex with Gαolf /Gß, which is coupled to D1 receptor (D1R). Here, we attempted to characterize the pathophysiological, neurochemical, and pharmacological features of mice deficient of Gγ7 gene. Gγ7 knockout mice exhibited age-dependent deficiency in rotarod behavior and increased dystonia-like clasping reflex without loss of striatal neurons. The neurochemical basis for the motor manifestations using immunoblot analysis revealed increased levels of D1R, ChAT and NMDA receptor subunits (NR1 and NR2B) concurrent with decreased levels of D2R and Gαolf , possibly because of the secondary changes of decreased Gαolf /Gγ7-mediated D1R transmission. These behavioral and neurochemical changes are closely related to those observed in Huntington's disease (HD) human subjects and HD model mice. Taking advantage of the finding of D2R down-regulation in Gγ7 knockout mice and the dopamine-mediated synergistic relationship in the control of locomotion between D2R-striatopallidal and D1R-stritonigral neurons, we hypothesized that D2-agonist pramipexole would reverse behavioral dyskinesia caused by defective D1R/Gαolf signaling. Indeed, the rotarod deficiency and clasping reflex were reversed by pramipexole treatment under chronic administration. These findings suggest that Gγ7 knockout mice could be a new type of movement disorders, including HD and useful for the evaluation of therapeutic candidates.
Assuntos
Benzotiazóis/uso terapêutico , Agonistas de Dopamina/uso terapêutico , Distonia/tratamento farmacológico , Distonia/metabolismo , Subunidades gama da Proteína de Ligação ao GTP/deficiência , Receptores de Dopamina D2/agonistas , Fatores Etários , Animais , Benzotiazóis/farmacologia , Corpo Estriado/efeitos dos fármacos , Corpo Estriado/metabolismo , Agonistas de Dopamina/farmacologia , Masculino , Camundongos , Camundongos Knockout , Pramipexol , Receptores de Dopamina D2/fisiologiaRESUMO
Objectives: Polycystic ovarian syndrome (PCOS) is an endocrine disorder associated with insulin resistance, hyperandrogenism, and sub-infertility. Virgin coconut oil (VCO) has been reported to have health benefits, such as anti-inflammatory, anti-oxidant, and antiviral properties. This study investigated the effects of dietary VCO supplementation on memory and cognitive impairment in female rats with letrozole induced PCOS. Methods: Thirty female rats were randomly divided into five groups. All rats except controls were treated with letrozole for 21 days to induce PCOS and were subsequently treated for 14 days with 10% VCO, clomiphene (CLO), or VCO + CLO. Three neurobehavioral tests were conducted: elevated plus maze, Y maze, and novel object recognition tests. Results: Our results indicated statistically elevated serum concentrations of sex hormones in rats with PCOS, compared with the control and treated groups. In addition, all treated groups showed significant reversal of the low serum concentrations of catalase and down-regulated gene expression of Nrf2 in the hippocampus seen in the PCOS rats. In addition, gene expression of acetylcholine esterase was up-regulated in PCOS rats, and was statistically reverted in the VCO treated groups. Conclusion: Anxiety-like behavior and impaired short-term memory were observed in PCOS rats; however, VCO supplementation reversed these effects by modulating the gene expression of Nrf2 and AchE.
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Erectile dysfunction (ED) is a major challenge for men. The drugs for its treatment are associated with side effects. Hence, in phytomedicinal research, where Anonna senegalensis (A. senegalensis) is a candidate with abundant phytochemicals possessing various pharmacological properties, but the sex-enhancing phytochemical is elusive in the literature. This study aimed to understand the molecular interaction of its potent molecule mediating male sexual enhancement. A library of 69 compounds from A. senegalensis was docked against the ED-targeted proteins. Sildenafil citrate was used as the reference standard. Thereafter, the lead compound was screened for drug-likeness by applying the Lipinski rule of 5 (RO5), pharmacokinetic properties, and bioactivity using SwissADME and Molinspiration web servers, respectively. The results show catechin as the lead phytochemical compound with a stronger binding affinity for most of the proteins of ED. Also, catechin demonstrates good compliance with the RO5, great pharmacokinetic profiles, and could be said to be a polypharmacological molecule with good bioactivity scores. The research findings unravel the potential of catechin (a phytochemical belonging to the flavonoids class) from A. senegalensis leaf as a potential male sexual enhancement molecule via its high binding affinity for most erectile dysfunction-targeted proteins. They may require further toxicity and therapeutic evaluations in vivo.
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Catequina , Disfunção Erétil , Humanos , Masculino , Disfunção Erétil/tratamento farmacológico , Catequina/uso terapêutico , Piperazinas/efeitos adversos , Purinas , Citrato de Sildenafila/farmacologia , Citrato de Sildenafila/uso terapêutico , Resultado do TratamentoRESUMO
BACKGROUND: Chronic myelogenous leukaemia (CML) constitutes about 15 % of adult leukaemia and is characterized by the overproduction of immature myeloid cells. METHODS: In this study, a virtual high throughput screening (vHTS) technique was employed to screen a library of phytochemicals of reported plants having anticancer activity. A docking score of -10 kcalmol-1 was used as the cut-off for the selection of phyto-compounds for pharmacophore-based virtual screening. Statistically robust and thoroughly validated QSAR model (R = 0.914, R2 = 0.836, Adjusted R2 = 0.764, LOO-CV= 0.6680) was derived for the inhibition of BCR-ABL kinase domain. RESULTS: The virtual screening, pharmacophore screening, QSAR model and molecular docking techniques applied herein revealed ellagic acid, a polyphenolic compound, as a potential competitive inhibitor of the BCR-ABL kinase domain. Ellagic acid binds to the inactive ABL state and forms similar interactions with key residues within the BCR-ABL Kinase domain as obtained in ponatinib (having inhibitory effects on the ABL thr-315I mutant). It forms hydrogen bond interaction with thr-315 residue (the gatekeeper residue). It is not likely to be prone to the various mutations associated with nilotinib because of its small size. CONCLUSION: The procedure of VHTs, Pharmacophore, QSAR, and molecular docking applied in this study could help in detecting more anti-CML compounds.
Assuntos
Proteínas de Fusão bcr-abl , Leucemia Mielogênica Crônica BCR-ABL Positiva , Trifosfato de Adenosina , Adulto , Resistencia a Medicamentos Antineoplásicos/genética , Ácido Elágico/farmacologia , Ensaios de Triagem em Larga Escala , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Simulação de Acoplamento Molecular , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , Relação Quantitativa Estrutura-AtividadeRESUMO
OBJECTIVES: Inhibition of HMG-CoA (3-hydroxy-3-methylglutaryl coenzyme A) reductase, the rate rate-determining enzyme for the biogenesis of cholesterol is known to show antineoplastic effects. Therefore, this study investigates the in-silico HMG-CoA reductase (HMGCR)-inhibitory and in-vivo anti-lipidaemic/anticancer effects of carotenoids from Spondias mombin. METHODS: Carotenoids from S. mombin leaves were characterized with the aid of liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS). The characterized phytochemicals were obtained from PubChem. They were docked into the orthosteric site of human HMGCR (Protein Data Bank code 1HW8) using AutoDock 4.0 suites. DMBA (7,12-dimethylbenz[a]anthracene) model of breast cancer was treated with the carotenoids extract from S. mombin (100 mg/kg and 200 mg/kg doses) to assess its anti-lipidaemic cum anticancer effects. KEY FINDINGS: Carotenoids from S. mombin; beta-carotene-15,15'-epoxide, astaxanthin and 7,7',8,8'-tetrahydro-ß-ß-carotene demonstrate HMGCR inhibition. They form hydrophobic interactions with key residues within the catalytic domain of HMGCR. The carotenoids extract exhibits anti-lipidaemic/anticancer effects, lowering serum triglyceride, LDL and cholesterol concentration. It increases HDL concentration and downregulates the expression of HMGR, AFP, CEACAM-3, BRCA-1 and HIF-1 mRNAs. CONCLUSION: Carotenoids from S. mombin demonstrate HMG-CoA reductase (HMGCR) inhibition, anti-lipidaemic, and anticancer effects. The inhibition of HMGCR by the carotenoids extract further poses it as a potential anti-hypercholesterolaemia compounds.
Assuntos
Anacardiaceae/química , Antineoplásicos Fitogênicos/farmacologia , Neoplasias da Mama/metabolismo , Carotenoides/farmacologia , Hidroximetilglutaril-CoA Redutases/metabolismo , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Hipolipemiantes/farmacologia , Acil Coenzima A/metabolismo , Animais , Anticolesterolemiantes/análise , Anticolesterolemiantes/farmacologia , Antineoplásicos Fitogênicos/análise , Antineoplásicos Fitogênicos/uso terapêutico , Mama/efeitos dos fármacos , Mama/metabolismo , Neoplasias da Mama/induzido quimicamente , Neoplasias da Mama/tratamento farmacológico , Carotenoides/análise , Regulação para Baixo , Feminino , Humanos , Hipercolesterolemia/sangue , Hipercolesterolemia/tratamento farmacológico , Hipercolesterolemia/metabolismo , Hiperlipidemias/sangue , Hiperlipidemias/tratamento farmacológico , Hiperlipidemias/metabolismo , Hipolipemiantes/análise , Hipolipemiantes/uso terapêutico , Lipídeos/sangue , Simulação de Acoplamento Molecular , Fitoterapia , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Ratos Wistar , Xantofilas/análise , Xantofilas/farmacologia , beta Caroteno/análise , beta Caroteno/farmacologiaRESUMO
Human epidermal growth factor 2 (HER2) is overexpressed in about 20% of breast cancer and is associated with a poor prognosis. We report in this study that carotenoid-enriched fractions from Spondias mombin demonstrate HER2 ATP kinase domain inhibition. HER2 breast carcinoma was modeled in female Wistar rats and authenticated via immunohistochemical studies. Inhibition of HER2 ATP kinase domain by the carotenoid-enriched fractions was investigated by molecular docking, atomistic simulation, and the expression of HER2 mRNA in HER2-positive breast carcinoma model in female Wistar rats. The therapeutic efficacy of the treatments (carotenoid-rich fractions) was determined by biochemical, tumor volume, and histopathological analysis. Immunohistochemical analysis revealed 7,12-dimethylbenz[a]anthracene (DMBA)-induced HER2-positive breast carcinoma. Phytoconstituents of the carotenoid-enriched fractions astaxanthin, 7,7',8,8'-tetrahydro-ß,ß-carotene, beta-carotene-15,15'-epoxide, and lapatinib (standard drug) demonstrate inhibition of HER2 with docking scores of -3.0, -8.5, -11.5, and -10.6 kcal/mol, respectively; and during atomistic simulation, the compounds ruptured the canonical active-state K753/E770 salt-bridge interaction. The treatment similarly downregulated HER2 mRNA expression significantly at p < 0.05. It also upregulated the expression of p53 and p27 mRNAs significantly at p < 0.05 and reduced creatinine and urea concentrations in the serum at p < 0.05. The tumor volume was also significantly reduced when compared with that of the untreated group. Carotenoid-enriched fractions from S. mombin demonstrate anti-HER2 positive breast carcinoma potentials via HER2 ATP kinase domain inhibition.
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Vascular endothelial growth factor (VEGF) and its receptor-2 (VEGFR-2) mediated tumorigenesis, metastasis, and angiogenesis are the cause of the increased levels of mortality associated with breast cancer and other forms of cancer. Inhibition of VEGF and VEGFR-2 provides a great therapeutic option in the management of cancer. This study employed VEGFR-2 kinase domain inhibition as an anti-angiogenic scaffold and further validate the anti-angiogenic effects of the lead phytochemicals, carotenoids from Spondias mombin in 7, 12-Dimethylbenz[a]anthracene (DMBA) model of breast carcinoma in Wistar rats. Phytochemicals characterized from 6 reported anti-cancer plants were screened against the VEGFR-2 kinase domain. The lead phytochemicals, carotenoids from Spondias mombin were isolated and subjected to Liquid Chromatography-Electrospray Ionization-Mass Spectrometry (LC-ESI-MS) for characterization. The anti-angiogenic potentials of the carotenoid isolates were validated in the DMBA model of breast carcinoma in female Wistar rats through assessment of the expression of anti-angiogenic related mRNAs, histopathological analysis, and molecular docking. Treatment with carotenoid isolates (100 mg/kg and 200 mg/kg) significantly (p < 0.05) downregulated the expression of VEGF, VEGFR, Epidermal Growth Factor Receptor (EGFR), Hypoxia-Inducible Factor-1(HIF-1), and Matrix Metalloproteinase-2 (MMP-2) mRNAs in the mammary tumours, while the expression of Chromodomain Helicase DNA-Binding Protein-1 (CHD-1) mRNA was significantly (p < 0.05) upregulated. DMBA induced comedo and invasive ductal subtypes of breast carcinoma. The binding of astaxanthin, 7,7',8,8'-tetrahydro-ß,ß-carotene, and beta-carotene-15,15'-epoxide to the ATP binding site led to the DFG-out conformation with binding energies of -8.2 kcal/mol, -10.3 kcal/mol, and -10.5 kcal/mol respectively. Carotenoid isolates demonstrated anti-angiogenic and anti-proliferating potentials via VEGFR-2 kinase domain inhibition.
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Breast cancer is the most prevalent cancer in women. X-linked inhibitor of apoptosis protein (XIAP) that is constantly overexpressed in cancer is a promising therapeutic target in cancer treatments. The mechanisms of the anticancer effects of carotenoid isolates of Spondias mombim in DMBA-induced breast cancer in Wistar rats through XIAP antagonism were investigated in the present study. Carotenoids isolated from the leaves of Spondias mombim were subjected to Liquid Chromatography/Mass Spectrometry (LC/MS) and Electrospray Ionization (ESI) for characterization. The characterized carotenoid isolates were docked against XIAP BIR2 domain and XIAP BIR3 domain. The anticancer effects of the carotenoid isolates of Spondias mombim in DMBA-induced breast cancer in Wistar rats were also investigated through the expression of XIAP, COX-2, TNF, BCl-2 mRNAs by qRT-PCR and biochemical parameters of catalase, lipid peroxidation, LDH, ALP, and ALT. These show the carotenoid isolates demonstrate anticancer effects by antagonism of XIAP, proapoptotic, and anti-inflammatory properties. PRACTICAL APPLICATIONS: The present study showed that carotenoids (astaxanthin, ß-carotene-15,15'-epoxide, and 7,7',8,8'-tetrahydro-ß, ß-carotene) isolated from the leaves of Spondias mombim are proapoptotic, it further gives credence to the chemopreventive abilities of carotenoids. This study validated XIAP as a druggable target in cancer treatment and hence more phytochemicals should be screened against it, for possible lead compounds of plant origin. Cancer cells often explore XIAP for antiapoptotic and resistance tendencies, hence, ß-carotene-15,15'-epoxide and 7,7',8,8'-tetrahydro-ß, ß-carotene (XIAP antagonists) are promising drug candidates that can withstand resistant and prone cancer cells to apoptotic cell death. There is a need to synthesize ß-carotene-15,15'-epoxide and 7,7',8,8'-tetrahydro-ß for further investigation in clinical studies.
Assuntos
Anacardiaceae , Neoplasias , Animais , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêutico , Carotenoides , Ratos , Ratos Wistar , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X/genéticaRESUMO
The anti-obesity and erythropoietic effects of crude ethanolic extracts of Garcinia cambogia (bitter kola) seeds on Wistar rats (Rattus norvegicus) were investigated. The rats were divided into three dosage groups: A (0 mg/kg of body weight), B (200 mg/kg) and C (400 mg/kg). Weight changes, plasma lipoprotein levels and the lipid profile of the liver, gastrointestinal system and adipose tissue were monitored as indices for anti-obesity, while the RBC (red blood cell) count (assessed by using a haemocytometer) was monitored as a measure of erythropoiesis. The extract was administered by gavage for 5 weeks. The results for each test group was compared statistically with those for the control (P<0.05). Analysis of the results showed a significant increase in RBC counts in both test groups and a decrease in weights of experimental animals. There was a dose-dependent decrease in the plasma level of very-low-density lipoprotein and a dose-dependent increase in the level of chylomicrons. There was a slight, but significant, decrease in the level of high-density lipoprotein and a significant increase in the level of LDL (low-density lipoprotein). There was significant dose-dependent decrease in the TAG (triacylglycerol) pool of adipose tissue and the liver of the test groups, but a significant increase in the TAG pool of the gastrointestinal system. The increase in the TAG pool of the gastrointestinal system is possibly compensatory. The results therefore confirm that ethanolic extracts of G. cambogia seeds have both haematologically enhancing and anti-obesity effects. The decrease in the high-density-lipoprotein level and an increase in the LDL level may play an important role in cardiovascular disease.
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Eritropoese/efeitos dos fármacos , Garcinia cambogia/química , Obesidade/tratamento farmacológico , Extratos Vegetais/farmacologia , Animais , Relação Dose-Resposta a Droga , Lipídeos/sangue , Masculino , Extratos Vegetais/uso terapêutico , Ratos , Ratos WistarRESUMO
There has been a sharp rise in the global prevalence of diabetes, obesity, and their comorbid conditions within the last decade prompting significant research into possible causes and cure via therapeutic intervention and lifestyle adjustments. Here, the molecular bases of antidiabetic plants used in the prehistorical treatment of diabetes and obesity are reviewed with particular focus on saponin as the phytotherapeutic principle. Until recently, the phytotherapeutic potentials of saponins have been masked in the heterogeneity of phytochemicals co-extractable during traditional preparations. With improved technique of purification and cutting edge biological assay methods, saponins have emerged as a regulator of primary biofuel availability through direct interaction with energy metabolism, cell signaling, and gene expression. Specific cases of lipoprotein lipase/peroxisome proliferator-activated receptor (PPAR)-gamma/phosphatidylinositide 3-kinase (PI-3-K)/protein kinase B (Akt) activation, adiponectin gene upregulation, fatty acid binding protein 4 repression (FABP4), and glucose transporter type 4 (Glut4) membrane exocytosis have been documented which provide molecular basis for hypocholesterolemic, hypoglycemic, and anti-obesity manifestations observed in experimental animals following saponin treatment. Although intensified research is required to characterize the pharmacophoric features in saponins exhibiting these interactions, however, this preliminary lead is valuable if the world will be free of diabetes, obesity, hypertension, hyperlipidemia, and atherosclerosis in no distant future.
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Biocombustíveis , Diabetes Mellitus/terapia , Saponinas/uso terapêutico , Glucose/metabolismo , Humanos , Plantas Medicinais/química , Saponinas/farmacologiaRESUMO
Herein, we investigated the role of periaqueductal gray (PAG)-resident microglia in the development of morphine tolerance and its underlying mechanisms. We showed that clodronate and minocycline known as microglia inhibitors reversed morphine tolerance, providing proof that microglia activation has key role in the development of morphine tolerance. The microglia-mediated anti-opioid mechanism occurs via sequential BDNF release and NMDA expression. Experimental evidence is provided here as conditional bdnf knockout mice (bdnfâ»/â») failed to develop tolerance following Cre-recombinase adenovirus treatment. Increased BDNF expression followed microglia activation in acute minocycline treatment reversible manner. Following BDNF release, NR2A subunit of NMDA receptor was upregulated in anti-BDNF reversible manner showing the contribution of BDNF signaling in the control of NMDA receptor expression following chronic morphine treatment. Our data provide compelling evidence that microglia activation and BDNF release are key regulators in opioid tolerance mechanism via glutaminergic synapse plasticity.