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1.
Cell Death Discov ; 10(1): 405, 2024 Sep 16.
Artículo en Inglés | MEDLINE | ID: mdl-39284830

RESUMEN

Derangements in protein homeostasis and associated proteotoxicity mark acute, chronic, and drug-induced hepatocellular injury. Metabolic dysfunction-associated proteasomal inhibition and the use of proteasome inhibitors often underlie such pathological hepatic proteotoxicity. In this study, we sought to identify a candidate deubiquitinating enzyme (DUB) responsible for reversing the proteotoxic damage. To this end, we performed a siRNA screening wherein 96 DUBs were individually knocked down in HepG2 cells under proteasomal inhibitor-induced stress for dual readouts, apoptosis, and cell viability. Among the putative hits, we chose JOSD1, a member of the Machado-Josephin family of DUBs that reciprocally increased cell viability and decreased cell death under proteotoxicity. JOSD1-mediated mitigation of proteotoxicity was further validated in primary mouse hepatocytes by gain and loss of function studies. Marked plasma membrane accumulation of monoubiquitinated JOSD1 in proteotoxic conditions is a prerequisite for its protective role, while the enzymatically inactive JOSD1 C36A mutant was conversely polyubiquitinated, does not have membrane localisation and fails to reverse proteotoxicity. Mechanistically, JOSD1 physically interacts with the suppressor of cytokine signalling 1 (SOCS1), deubiquitinates it and enhances its stability under proteotoxic stress. Indeed, SOCS1 expression is necessary and sufficient for the hepatoprotective function of JOSD1 under proteasomal inhibition. In vivo, adenovirus-mediated ectopic expression or depletion of JOSD1 in mice liver respectively protects or aggravates hepatic injury when challenged with proteasome blocker Bortezomib. Our study thus unveils JOSD1 as a potential candidate for ameliorating hepatocellular damage in liver diseases.

2.
J Ethnopharmacol ; 328: 117991, 2024 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-38460574

RESUMEN

ETHNOPHARMACOLOGICAL RELEVANCE: Glinus oppositifolius (L.) Aug. DC. belongs to the family Molluginaceae, an annual prostrate herb traditionally used to treat inflammations, arthritis, malarial, wounds, fevers, diarrhoea, cancer, stomach discomfort, jaundice, and intestinal parasites. However, the anti-arthritic activity of the aerial part has still not been reported. AIM OF THE STUDY: To investigate the antioxidant and anti-arthritic activity of G. oppositifolius in Complete Freund's Adjuvant (CFA) induced rats. MATERIALS AND METHODS: The dried aerial parts of this plant material were defatted with n-hexane and extracted by methanol using a soxhlet apparatus. The in vitro anti-arthritic activity of methanolic extract of G. oppositifolius (MEGO) was evaluated in protein denaturation, membrane stabilization, and inhibition of proteinase assay at 25, 50, 100, 200, and 400 µg/ml concentrations. Female Wistar rats were immunized sub-dermally into the right hind paw with 0.1 ml of CFA. Rats were administered with MEGO at doses of 200 and 400 mg/kg once daily for fourteen days after arthritis induction. Assessment of arthritis was performed by measuring paw diameter, arthritic index, arthritic score, body weight, organ weight, and hematological and biochemical parameters, followed by the analysis of pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNF-α), interleukin 6 (IL-6), interleukin-1-beta (IL-1ß), cyclooxygenase-2 (COX-2), interleukin 13 (IL-13) and interleukin 10 (IL-10) and histopathological study. In vivo antioxidant effect was investigated in enzymatic assays. The presence of phytoconstituents was analyzed by Gas Chromatography-Mass Spectrometry (GC-MS) and Liquid Chromatography-Mass Spectrometry (LC-MS), respectively. In silico molecular docking study of the compounds was carried out against COX-2, IL-1ß, IL-6, and TNF-α using AutoDock 4.2 and BIOVIA-Discovery Studio Visualizer software. RESULTS: MEGO's in vitro anti-arthritic activity showed dose-dependent inhibition of protein denaturation, membrane stabilization, and proteinase inhibition, followed by significant in vivo anti-arthritic activity. The rats treated with MEGO showed tremendous potential in managing arthritis-like symptoms by restoring hematological, biochemical, and histological changes in CFA-induced rats. MEGO (200 and 400 mg/kg) showed a significant alleviation in the levels of hyper expressed inflammatory mediators (TNF-α, IL-1ß, and IL-6) and oxidative stress (SOD, CAT, GSH, and LPO) in CFA-induced rats. Spergulagenin-A as identified by LC-MS analysis, exhibited the highest binding affinity against COX-2 (-8.6), IL-1ß (7.2 kcal/mol), IL-6 (-7.4 kcal/mol), and TNF-α (-6.5 kcal/mol). CONCLUSIONS: Provided with the comprehensive investigation, methanolic extract of G. oppositifolius against arthritic-like condition is a proof of concept that revalidates its ethnic claim. The presence of Spergulagenin-A might be responsible for the anti-arthritic activity.


Asunto(s)
Artritis Experimental , Molluginaceae , Ratas , Animales , Factor de Necrosis Tumoral alfa , Extractos Vegetales/farmacología , Extractos Vegetales/uso terapéutico , Interleucina-6 , Antiinflamatorios/farmacología , Antiinflamatorios/uso terapéutico , Ratas Wistar , Ciclooxigenasa 2 , Simulación del Acoplamiento Molecular , Quimiometría , Artritis Experimental/inducido químicamente , Artritis Experimental/tratamiento farmacológico , Metanol/química , Antioxidantes/uso terapéutico , Interleucina-13 , Péptido Hidrolasas , Componentes Aéreos de las Plantas
3.
Cell Rep ; 42(6): 112543, 2023 06 27.
Artículo en Inglés | MEDLINE | ID: mdl-37224016

RESUMEN

Gonadotropes in the anterior pituitary gland are essential for fertility and provide a functional link between the brain and the gonads. To trigger ovulation, gonadotrope cells release massive amounts of luteinizing hormone (LH). The mechanism underlying this remains unclear. Here, we utilize a mouse model expressing a genetically encoded Ca2+ indicator exclusively in gonadotropes to dissect this mechanism in intact pituitaries. We demonstrate that female gonadotropes exclusively exhibit a state of hyperexcitability during the LH surge, resulting in spontaneous [Ca2+]i transients in these cells, which persist in the absence of any in vivo hormonal signals. L-type Ca2+ channels and transient receptor potential channel A1 (TRPA1) together with intracellular reactive oxygen species (ROS) levels ensure this state of hyperexcitability. Consistent with this, virus-assisted triple knockout of Trpa1 and L-type Ca2+ subunits in gonadotropes leads to vaginal closure in cycling females. Our data provide insight into molecular mechanisms required for ovulation and reproductive success in mammals.


Asunto(s)
Gonadotrofos , Adenohipófisis , Ratones , Animales , Femenino , Hormona Luteinizante , Hipófisis , Ovulación , Mamíferos
4.
Methods Mol Biol ; 2455: 255-265, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35213000

RESUMEN

Activation of the inflammasome in hepatocytes and the liver-resident macrophages is associated with drug-induced hepatotoxicity and a plethora of metabolic diseases including nonalcoholic steatohepatitis (NASH). Initiation of this innate immune response requires two concomitant signals resulting in the formation of a molecular assembly that post-transcriptionally maturates a specific set of cytokines. While signal 1 results from the engagement and activation of pattern recognition receptors, signal 2 can be induced by diverse stimuli including adenosine triphosphate (ATP). Among various modules, NOD-like receptor 3 (NLRP3) inflammasome activation followed by caspase-1-dependent proIL-1ß maturation has been observed in both preclinical models and NASH patients suggesting the crucial importance of inflammasome activation in NAFLD progression. The protocol reported here depicts an ex vivo method for investigating the role of inflammasome activation in macrophages and its impact on hepatocytes. We first described a rapid protocol for the isolation of primary Kupffer cells (KC) and hepatocytes from the murine liver. Next, to investigate the crosstalks between KCs and hepatocytes in the context of inflammasome activation, isolated KCs were activated with lipopolysaccharide (LPS), alone or in tandem with ATP, which resulted in inflammasome activation in KCs evident by abundant IL-1ß secretion. Isolated primary hepatocytes were treated with conditioned medium (CM) from activated KCs to investigate the effect of inflammasome activation by various readouts. Moreover, this model also enabled us to investigate the role of specific cytokines by neutralizing them in the CM of inflammasome-activated KC. This precise ex vivo method provides a comprehensive protocol for investigating hepatocellular inflammasome activation.


Asunto(s)
Inflamasomas , Enfermedad del Hígado Graso no Alcohólico , Animales , Humanos , Inflamasomas/metabolismo , Interleucina-1beta/metabolismo , Macrófagos del Hígado/metabolismo , Lipopolisacáridos/metabolismo , Lipopolisacáridos/farmacología , Hígado/metabolismo , Ratones , Ratones Endogámicos C57BL , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Enfermedad del Hígado Graso no Alcohólico/metabolismo
5.
Indian J Otolaryngol Head Neck Surg ; 73(4): 467-473, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34692459

RESUMEN

Allergic rhinitis (AR) is one of the most common types of allergy worldwide. It has significant negative impact on the quality of life (QOL). One of the available causal treatments of AR is allergen specific immunotherapy which remains effective even after the end of treatment course, unlike symptomatic drugs. AR patients aged above five years, allergic to unavoidable allergen like house dust, mite etc., and refractory to maximal pharmacotherapy were included in present study. Patients allergic to avoidable allergen, taking beta-blocker medication, having other immunological disease, and who were pregnant, breast-feeding or lost to follow up, were excluded from the study. All patients included in the study underwent sublingual immunotherapy (SLIT). The impact of treatment is measured by calculating the difference between SNOT-20 score before and after treatment (which is 6 months interval). Total 30 patients were studied. Paired-t test calculated value of cumulative score and nasal symptom score are 7.853 and 6.85 respectively. Both are greater than table value of 2.46. So paired-t test shows that SLIT is very much effective in treatment of AR. The present study re-establish the fact that SLIT not only reduces AR symptoms, it also improves the QOL. It has very good patient compliance with minimal side effects.

6.
Biochem J ; 478(17): 3297-3317, 2021 09 17.
Artículo en Inglés | MEDLINE | ID: mdl-34409981

RESUMEN

Alzheimer's Disease (AD) and Type 2 Diabetes (T2D) share a common hallmark of insulin resistance. Reportedly, two non-canonical Receptor Tyrosine Kinases (RTKs), ALK and RYK, both targets of the same micro RNA miR-1271, exhibit significant and consistent functional down-regulation in post-mortem AD and T2D tissues. Incidentally, both have Grb2 as a common downstream adapter and NOX4 as a common ROS producing factor. Here we show that Grb2 and NOX4 play critical roles in reducing the severity of both the diseases. The study demonstrates that the abundance of Grb2 in degenerative conditions, in conjunction with NOX4, reverse cytoskeletal degradation by counterbalancing the network of small GTPases. PAX4, a transcription factor for both Grb2 and NOX4, emerges as the key link between the common pathways of AD and T2D. Down-regulation of both ALK and RYK through miR-1271, elevates the PAX4 level by reducing its suppressor ARX via Wnt/ß-Catenin signaling. For the first time, this study brings together RTKs beyond Insulin Receptor (IR) family, transcription factor PAX4 and both AD and T2D pathologies on a common regulatory platform.


Asunto(s)
Enfermedad de Alzheimer/metabolismo , Quinasa de Linfoma Anaplásico/metabolismo , Citoesqueleto/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Regulación hacia Abajo , Proteínas de Homeodominio/metabolismo , MicroARNs/metabolismo , Factores de Transcripción Paired Box/metabolismo , Proteínas Tirosina Quinasas Receptoras/metabolismo , Vía de Señalización Wnt/genética , Adulto , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/patología , Quinasa de Linfoma Anaplásico/genética , Animales , Encéfalo/metabolismo , Encéfalo/patología , Proteínas del Citoesqueleto/metabolismo , Diabetes Mellitus Tipo 2/patología , Modelos Animales de Enfermedad , Femenino , Células Hep G2 , Proteínas de Homeodominio/genética , Humanos , Hígado/metabolismo , Hígado/patología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Persona de Mediana Edad , Factores de Transcripción Paired Box/genética , Proteínas Tirosina Quinasas Receptoras/genética , Transfección
7.
STAR Protoc ; 2(4): 101027, 2021 12 17.
Artículo en Inglés | MEDLINE | ID: mdl-34977673

RESUMEN

Here, we describe a robust protocol using mouse models to screen potential insulin-stabilizers and insulin moieties. We have generated a mouse model of amyloidoma, found in diabetic patients undergoing insulin therapy. This model can be used to screen potential insulin stabilizers and insulin moieties to prevent amyloidoma formation. This protocol can further be used for the preclinical validation of therapeutically relevant insulin stabilizers and formulations. The protocol highlights all the critical steps for generating amyloidoma in a preclinical model. For complete details on the use and execution of this profile, please refer to Mukherjee et al. (2021).


Asunto(s)
Amiloide , Amiloidosis , Modelos Animales de Enfermedad , Evaluación Preclínica de Medicamentos/métodos , Amiloide/química , Amiloide/efectos de los fármacos , Amiloide/metabolismo , Amiloidosis/metabolismo , Amiloidosis/patología , Animales , Insulina/química , Insulina/metabolismo , Masculino , Ratones , Ratones Endogámicos BALB C
8.
Artif Organs ; 44(11): E494-E508, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32410232

RESUMEN

Cartilage is avascular with limited to no regenerative capacity, so its loss could be a challenge for reconstructive surgery. Current treatment options for damaged cartilage are also limited. In this aspect there is a tremendous need to develop an ideal cartilage-mimicking biomaterial that could repair maxillofacial defects. Considering this fact in this study we have prepared twelve silicone-based materials (using Silicone 40, 60, and 80) reinforced with hydroxyapatite, tri-calcium phosphate, and titanium dioxide which itself has proven their efficacy in several studies and able to complement the shortcomings of using silicones. Among the mechanical properties (Young's modulus, tensile strength, percent elongation, and hardness), hardness of Silicone-40 showed similarities with goat ear (P > .05). Silicone peaks have been detected in FTIR. Both AFM morphology and SEM images of the samples confirmed more roughed surfaces. All the materials were nonhemolytic in hemocompatibility tests, but among the twelve materials S2, S3, S5, and S6 showed the least hemolysis. For all tested bacterial strains, adherence was lower on each material than that grown on the plain industrial silicone material which was used as a positive control. S2, S3, S5, and S6 samples were selected as the best based on mechanical characterizations, surface characterizations, in vitro hemocompatibility tests and bacterial adherence activity. So, outcomes of this present study would be promising when developing ideal cartilage-mimicking biocomposites and their emerging applications to treat maxillofacial defects due to cartilage damage.


Asunto(s)
Materiales Biocompatibles/química , Materiales Biomiméticos/química , Cartílago/química , Siliconas/química , Fosfatos de Calcio/química , Durapatita/química , Dureza , Humanos , Ensayo de Materiales , Resistencia a la Tracción , Titanio/química
9.
J Comput Aided Mol Des ; 34(8): 915-927, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-32270361

RESUMEN

Insulin aggregation is the leading cause of considerable reduction in the amount of active drug molecules in liquid formulations manufactured for diabetes management. Phenolic compounds, such as phenol and m-cresol, are routinely used to stabilize insulin in a hexameric form during its commercial preparation. However, long term usage of commercial insulin results in various adverse secondary responses, for which toxicity of the phenolic excipients is primarily responsible. In this study we aimed to find out a nontoxic insulin stabilizer. To that end, we have selected resveratrol, a natural polyphenol, as a prospective nontoxic insulin stabilizer because of its structural similarity with commercially used phenolic compounds. Atomic force microscopy visualization of resveratrol-treated human insulin revealed that resveratrol has a unique ability to arrest hINS in a soluble oligomeric form having discrete spherical morphology. Most importantly, resveratrol-treated insulin is nontoxic for HepG2 cells and it effectively maintains low blood glucose in a mouse model. Cryo-electron microscopy revealed 3D morphology of resveratrol-stabilized insulin that strikingly resembles crystal structures of insulin hexamer formulated with m-cresol. Significantly, we found that, in a condition inductive to amyloid fibrillation at physiological pH, resveratrol is capable of stabilizing insulin more efficiently than m-cresol. Thus, this study describes resveratrol as an effective nontoxic natural molecule that can be used for stabilizing insulin in a bioactive oligomeric form during its commercial formulation.


Asunto(s)
Excipientes/química , Insulina/química , Insulina/farmacocinética , Resveratrol/química , Animales , Rastreo Diferencial de Calorimetría , Microscopía por Crioelectrón , Liberación de Fármacos , Estabilidad de Medicamentos , Dispersión Dinámica de Luz , Células Hep G2 , Humanos , Masculino , Ratones Endogámicos BALB C , Simulación del Acoplamiento Molecular , Estabilidad Proteica
10.
Colloids Surf B Biointerfaces ; 172: 555-564, 2018 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-30218981

RESUMEN

Mucoadhesive type ocular film has been prepared for studying the anti-inflammatory potential of amlodipine (AML) on carrageenan-induced rabbit model and the effect of sulphobutyl-ether-beta-cyclodextrin on corneal permeation was tested. Hydroxypropyl methylcellulose (HPMC) ocular film was prepared after complexation of amlodipine with ß-cyclodextrin, (BCD), hydroxypropyl ß-cyclodextrin (HPCD), and sulfobutylether ß-cyclodextrin (SBCD). The film without cyclodextrin showed a maximum swelling, and erosion to the highest extent. Both drug release and permeation were highly diffusion controlled and highest improvement was observed with SBCD due to increased dissolution, compared to other formulations with or without cyclodextrin. Highest binding energy and highest extent of amorphization were noticed in the SBCD film formulation. Improved amlodipine release in-vitro and ocular permeation were found by the HPMC film formulation after complexation of the drug with cyclodextrins wherein SBCD exhibited both to the highest extent. Binary and ternary systems molecular docking studies confirmed the lowest energy of binding between amlodipine and BCD compared to HBCD and SBCD. Signs of acute inflammation were mitigated within 2 h of film application in the cul-de-sac. Presence of sulphobutyl-ether ß-cyclodextrin in the amlodipine-HPMC film can improve ocular permeation significantly and could be utilized as mucoadhesive type formulation for anti-inflammatory activity.


Asunto(s)
Amlodipino/farmacología , Antiinflamatorios/farmacología , Ojo/efectos de los fármacos , Simulación del Acoplamiento Molecular , Moco/química , beta-Ciclodextrinas/química , Adhesividad , Amlodipino/química , Animales , Antiinflamatorios/química , Rastreo Diferencial de Calorimetría , Masculino , Permeabilidad , Conejos , Ovinos , Espectroscopía Infrarroja por Transformada de Fourier , Difracción de Rayos X
11.
J Clin Diagn Res ; 11(5): CC11-CC13, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-28658755

RESUMEN

INTRODUCTION: Smoking is established as the most important causative factor responsible for Chronic Obstructive Pulmonary Disease (COPD). Occurrence of allergy in COPD patients causes acute exacerbation of this disease, but role of allergy is not established in aetiopathogenesis of COPD. AIM: The present study was aimed at evaluation of occurrence of COPD in patients having symptoms suggestive of respiratory allergy. MATERIALS AND METHODS: An observational cross-sectional study was conducted to evaluate occurrence of COPD in patients having respiratory allergic symptoms by routine spirometric screening. Five hundred and fifty urban patients aged 18-60 years (both gender) ailing from chronic respiratory symptoms like cough, wheeze and Shortness Of Breath (SOB), who were referred from OPDs of RGKMCH, Kolkata, were included in this study. After obtaining detailed clinical profile, patients were divided into two groups: subjects having additional clinical symptoms suggestive of respiratory allergy (n=260) like nasal catarrh, nasal stuffiness and sneezing and subjects with no symptoms suggestive of respiratory allergy (n=290). Thereafter, routine spirometry was carried out following recommendations of ATS/ERS (2005). Patients were then categorized based on FVC, FEV1, FEV1/FVC, FEF25-75 and PEFR percent predicted values. RESULTS: Study revealed that 18.97% of non-allergic population was suffering from COPD whereas only 7.69% of allergic subjects had COPD. This difference was statistically highly significant (p=0.0001). Although there was no significant difference in prevalence of respiratory symptoms between these two groups. CONCLUSION: Present study concludes that patients with respiratory allergy may have coexistent COPD but occurrence of COPD is much less than that in patients with no respiratory allergy.

12.
Antioxid Redox Signal ; 27(16): 1269-1280, 2017 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-28264587

RESUMEN

AIMS: Synaptic deficits are known to underlie the cognitive dysfunction seen in Alzheimer's disease (AD). Generation of reactive oxygen species (ROS) by ß-amyloid has also been implicated in AD pathogenesis. However, it is unclear whether ROS contributes to synaptic dysfunction seen in AD pathogenesis and, therefore, we examined whether altered redox signaling could contribute to synaptic deficits in AD. RESULTS: Activity dependent but not basal translation was impaired in synaptoneurosomes from 1-month old presymptomatic APPSwe/PS1ΔE9 (APP/PS1) mice, and this deficit was sustained till middle age (MA, 9-10 months). ROS generation leads to oxidative modification of Akt1 in the synapse and consequent reduction in Akt1-mechanistic target of rapamycin (mTOR) signaling, leading to deficiency in activity-dependent protein translation. Moreover, we found a similar loss of activity-dependent protein translation in synaptoneurosomes from postmortem AD brains. INNOVATION: Loss of activity-dependent protein translation occurs presymptomatically early in the pathogenesis of AD. This is caused by ROS-mediated loss of pAkt1, leading to reduced synaptic Akt1-mTOR signaling and is rescued by overexpression of Akt1. ROS-mediated damage is restricted to the synaptosomes, indicating selectivity. CONCLUSIONS: We demonstrate that ROS-mediated oxidative modification of Akt1 contributes to synaptic dysfunction in AD, seen as loss of activity-dependent protein translation that is essential for synaptic plasticity and maintenance. Therapeutic strategies promoting Akt1-mTOR signaling at synapses may provide novel target(s) for disease-modifying therapy in AD. Antioxid. Redox Signal. 27, 1269-1280.


Asunto(s)
Enfermedad de Alzheimer/metabolismo , Biosíntesis de Proteínas , Proteínas Proto-Oncogénicas c-akt/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Sinapsis/metabolismo , Animales , Encéfalo/metabolismo , Modelos Animales de Enfermedad , Ratones , Plasticidad Neuronal , Transducción de Señal , Serina-Treonina Quinasas TOR/metabolismo
13.
Acta Pol Pharm ; 74(1): 137-145, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-29474770

RESUMEN

A series of 2-oxindole derivatives were synthesized and evaluated for cytotoxic activity against different human and murine cancer cell lines and cancer chemopreventive activity. Among the tested compounds VS-06, 08, 12 and 17 displayed cytotoxic activity in the range of 5.0 to 8.5 pM against human T-lymphocyte cells (CEM). Results showed that molecules with electron withdrawing substituent at 4 position of N-phenylacetamide group exhibited an increase in activity against the human tumor cell line CEM. The cancer chemo- preventive effect of VS-01 (IC50 = 451 nM) displayed equipotent activity in comparison to standard oleanolic acid (IC50 = 449 nM).


Asunto(s)
Anticarcinógenos/síntesis química , Antineoplásicos/síntesis química , Animales , Anticarcinógenos/farmacología , Antineoplásicos/farmacología , Línea Celular Tumoral , Humanos , Relación Estructura-Actividad
14.
Chempluschem ; 81(1): 100-107, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31968740

RESUMEN

A facile method for the synthesis of highly fluorescent manganese-doped zinc sulfide (ZnS:Mn) nanocrystals covalently functionalized with polyethylene glycol conjugated graphene oxide (GO-PEG) for drug delivery and cell labeling is reported. First, covalently functionalized GO with PEG-bis(amine) to enhance the solubility and biocompatibility in water and physiological buffers. Second, glutathione (GSH)-coated ZnS:Mn-doped nanocrystals were covalently grafted onto GO-PEG. An acid-amidation process was employed to obtain GO-PEG/ZnS:Mn nanocomposites, which were characterized by UV/Vis, photoluminescence, and Fourier transform infrared spectroscopies, and transmission electron microscopy. Finally, the anticancer drug doxorubicin (DOX) was noncovalently loaded onto these GO-PEG/ZnS:Mn composite particles. High drug entrapment efficiency (100 % due to more GO surface available for binding), slow in vitro release of drug (ca. 40 % at acidic pH), better HeLa cancer cell killing efficiency (ca. 85 %), and cell labeling capability are the important traits of these DOX-loaded nanocomposites. It is believed these novel fluorescent [GO-PEG/ZnS:Mn]-DOX composite particles have great potential as theranostic agents in cancer diagnosis and therapy.

15.
Phys Chem Chem Phys ; 17(29): 19139-48, 2015 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-26136209

RESUMEN

Non-native and denatured states of proteins have received increasing attention because of their relevance to issues such as protein folding and stability. In this context, the pathway of polypeptide collapse and random coil formation in a denatured protein is a subject of much interest. Most proteins so far studied have shown monotonic expansion of their hydrodynamic radius (RH) in the presence of increasing concentration of chaotropes. We have studied GdnHCl-induced folding transitions and conformational states of a multi-domain protein, bovine gamma globulin, using fluorescence, circular dichroism and fluorescence correlation spectroscopy (FCS). FCS measurements showed that for gamma globulin, contrary to the observed trend, RH decreases with increasing GdnHCl concentration up to 3 M. At higher GdnHCl concentration, RH starts to increase but exhibits complicated behavior in the form of two sharp maxima at 4 M and 7 M. Further experiments suggest that the maximum at 4 M GdnHCl arises due to electrostatic interaction, whereas the one at 7 M GdnHCl corresponds to the usual expanded conformation due to denaturation. Beyond 7 M GdnHCl, RH decreases drastically and is shown to result from fragmentation of the protein caused by rupture of disulphide bonds by the high GdnHCl concentration. Our results demonstrate the capability of FCS in revealing intricate details of the unfolding trajectory that eludes conventional ensemble techniques such as fluorescence and CD.


Asunto(s)
gammaglobulinas/química , Animales , Bovinos , Dicroismo Circular , Espectrometría de Fluorescencia
16.
Pharmacogn Rev ; 4(7): 95-105, 2010 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22228948

RESUMEN

The medicinal plants are widely used by the traditional medicinal practitioners for curing various diseases in their day to day practice. In traditional system of medicine, different parts (leaves, stem, flower, root, seeds and even whole plant) of Ocimum sanctum Linn. have been recommended for the treatment of bronchitis, malaria, diarrhea, dysentery, skin disease, arthritis, eye diseases, insect bites and so on. The O. sanctum L. has also been suggested to possess anti-fertility, anticancer, antidiabetic, antifungal, antimicrobial, cardioprotective, analgesic, antispasmodic and adaptogenic actions. Eugenol (1-hydroxy-2-methoxy-4-allylbenzene), the active constituents present in O. sanctum L. have been found to be largely responsible for the therapeutic potentials. The pharmacological studies reported in the present review confirm the therapeutic value of O. sanctum L. The results of the above studies support the use of this plant for human and animal disease therapy and reinforce the importance of the ethno-botanical approach as a potential source of bioactive substances.

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