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1.
Mol Cell Endocrinol ; 570: 111932, 2023 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-37080378

RESUMO

OBJECTIVE: Glucagon receptor (GCGR) antagonism elicits antihyperglycemic effects in rodents and humans. The present study investigates whether the well characterised peptide-based GCGR antagonist, desHis1Pro4Glu9-glucagon (Lys12PAL), alters alpha-cell turnover or identity in mice. METHODS: Multiple low-dose streptozotocin (STZ) treated (50 mg/kg bw, 5 days) transgenic GluCreERT2;ROSA26-eYFP mice were employed. STZ mice received twice daily administration of saline vehicle or desHis1Pro4Glu9-glucagon (Lys12PAL), at low- or high-dose (25 and 100 nmol/kg, respectively) for 11 days. RESULTS: No GCGR antagonist induced changes in food or fluid intake, body weight or glucose homeostasis were observed. As expected, STZ dramatically reduced (P < 0.001) islet numbers and increased (P < 0.01) alpha-to beta-cell ratio, which was linked to elevated (P < 0.05) levels of beta-cell apoptosis. Whilst treatment with desHis1Pro4Glu9-glucagon (Lys12PAL) decreased (P < 0.05-P < 0.001) alpha- and beta-cell areas, it also helped restore the classic rodent islet alpha-cell mantle in STZ mice. Interestingly, low-dose desHis1Pro4Glu9-glucagon (Lys12PAL) increased (P < 0.05) alpha-cell apoptosis rates whilst high dose decreased (p < 0.05) this parameter. This difference reflects substantially increased (P < 0.001) alpha-to beta-cell transdifferentiation following high dose desHis1Pro4Glu9-glucagon (Lys12PAL) treatment, which was not fully manifest with low-dose therapy. CONCLUSIONS: Taken together, the present study indicates that peptidic GCGR antagonists can positively influence alpha-cell turnover and lineage in identity in multiple low-dose STZ mice, but that such effects are dose-related.


Assuntos
Insulina , Receptores de Glucagon , Humanos , Camundongos , Animais , Hiperplasia , Glucagon/farmacologia , Glicemia
2.
J Endocrinol ; 259(2)2023 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-37650517

RESUMO

The present study examines differences in metabolic and pancreatic islet adaptative responses following streptozotocin (STZ) and hydrocortisone (HC) administration in male and female transgenic GluCreERT2/Rosa26-eYFP mice. Mice received five daily doses of STZ (50 mg/kg, i.p.) or 10 daily doses of HC (70 mg/kg, i.p.), with parameters assessed on day 11. STZ-induced hyperglycaemia was evident in both sexes, alongside impaired glucose tolerance and reduced insulin concentrations. HC also had similar metabolic effects in male and female mice resulting in classical increases of circulating insulin indicative of insulin resistance. Control male mice had larger pancreatic islets than females and displayed a greater reduction of islet and beta-cell area in response to STZ insult. In addition, female STZ mice had lower levels of beta-cell apoptosis than male counterparts. Following HC administration, female mouse islets contained a greater proportion of alpha cells when compared to males. All HC mice presented with relatively comparable increases in beta- and alpha-cell turnover rates, with female mice being slightly more susceptible to HC-induced beta-cell apoptosis. Interestingly, healthy control female mice had inherently increased alpha-to-beta-cell transdifferentiation rates, which was decreased by HC treatment. The number of glucagon-positive alpha cells altering their lineage to insulin-positive beta cells was increased in male, but not female, STZ mice. Taken together, although there was no obvious sex-specific alteration of metabolic profile in STZ or HC mice, subtle differences in pancreatic islet morphology emphasises the impact of sex hormones on islets and importance of taking care when interpreting observations between males and females.


Assuntos
Células Secretoras de Glucagon , Ilhotas Pancreáticas , Feminino , Masculino , Camundongos , Animais , Insulina , Glucagon , Camundongos Transgênicos , Hidrocortisona
3.
Indian J Psychiatry ; 64(4): 354-363, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36060721

RESUMO

Background: Literature suggests that the COVID-19 pandemic has resulted in poor sleep quality, especially among the infected population. However, literature regarding the effect of COVID-19 pandemic and SARS-CoV-2 infection on occurrence of insomnia, restless legs syndrome and dream enactment behavior is either scarce or unavailable. Methods: This study was planned to assess the effect of SARS-CoV-2 infection on the occurrence of insomnia, restless legs syndrome (RLS) and dream enactment behavior (DEB). For this cross-sectional study, a questionnaire comprising of items related to demographic details, past medical history, and information related to SARS-CoV-2 infection was distributed through social media. Insomnia was diagnosed using clinical criteria. RLS, DEB, sleep quality, depression and anxiety were assessed using a validated questionnaire. Information regarding the use of hypnotic medications was also gathered. Results: Of the 1596 respondents, 37.2% reported disturbed sleep while insomnia was reported by 22.6% respondents. 27.3% of respondents reported RLS and 17.4% suffered DEB. The odds of insomnia were greater among males (OR = 1.27; 95% CI: 1.03-1.58; P < 0.02) and among those who had SARS-CoV-2 infection (OR = 1.76; 95% CI = 1.42-2.19; P < 0.001). Similarly, SARS-CoV-2 infection was also associated with increased odds of RLS (OR = 2.48; 95% CI = 1.98-3.11; P < 0.001) and DEB (OR = 1.58; 95%CI = 1.21-2.06; P < 0.001). Insomnia, RLS and DEB were more frequent among respondents who required oxygen therapy, those who experienced loss of taste and/or smell, depression and anxiety. Prevalence of insomnia, DEB and RLS was higher than said prevalence among respondents with no history of SARS-CoV-2 infection, but lower than that of those with positive history of SARS-CoV-2 infection. 5.3% of respondents reported taking hypnotic medications before infection, 7% during infection and 5.3% after infection. Conclusion: SARS-CoV-2-infection-related factors in association with environmental factors have increased the prevalence of insomnia, DEB and RLS among subjects having infection. SARS-CoV-2-associated immunological changes, hypoxia and neurotropism may play a role in occurrence of insomnia, DEB and RLS.

4.
J Pharm Pharm Sci ; 13(4): 495-509, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-21486527

RESUMO

PURPOSE: Solid lipid nanoparticles (SLN) have emerged as carriers for therapeutic peptides, proteins, antigens and bioactive molecules. We have explored the potential of SLN as carrier for Hepatitis B surface antigen (HBsAg) by surface modifications to enhance their loading efficiency and the cellular uptake, using subcutaneous route. METHODS: Four different formulations of SLN were prepared by solvent injection method and characterized for various physical properties: particle size, surface morphology, shape, zeta potential, polydispersity, X-ray diffraction analysis, release profile and entrapment efficiency. HBsAg loaded SLN were studied for their functional characteristics, in vitro cellular uptake and internalization studies by human dendritic cells, macrophages and fibroblasts, T cell proliferation and TH1/TH2 response. Humoral immune response elicited by subcutaneously administered HBsAg containing SLN formulations were studied in vivo in mice. RESULTS: Compared to soluble HBsAg; SLN, particularly the mannosylated formulation, showed better cellular uptake, lesser cytotoxicity and induction of greater TH1 type of immune response. They also showed better immunological potential by producing sustained antibody titer. CONCLUSION: Mannosylated SLN appears to be promising as carrier for vaccine delivery against hepatitis B as ascertained by in vitro and in vivo studies, however further investigations on humans are required to establish their potential as vaccines against hepatitis B infection.


Assuntos
Antígenos de Superfície da Hepatite B/administração & dosagem , Vacinas contra Hepatite B/administração & dosagem , Nanopartículas , Animais , Proliferação de Células/efeitos dos fármacos , Células Dendríticas/metabolismo , Feminino , Fibroblastos/metabolismo , Hepatite B/imunologia , Hepatite B/prevenção & controle , Antígenos de Superfície da Hepatite B/imunologia , Vacinas contra Hepatite B/imunologia , Humanos , Injeções Subcutâneas , Lipídeos/química , Macrófagos/metabolismo , Manose/química , Camundongos , Camundongos Endogâmicos BALB C , Tamanho da Partícula , Linfócitos T/metabolismo , Células Th1/imunologia , Células Th2/imunologia , Difração de Raios X
5.
Nanomedicine ; 6(4): 590-6, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20093197

RESUMO

Indinavir, as a protease inhibitor with a short biological half life, variable pH-dependent oral absorption, and extensive first-pass metabolism, presents a challenge with respect to its oral administration. The current work aims to formulate and characterize indinavir-bearing ethanolic liposomes (ethosomes), and to investigate their enhanced transdermal delivery potential. The prepared ethanolic liposomes were characterized to be spherical, unilamellar structures having low polydispersity, nanometric size range, and improved entrapment efficiency over other delivery formulations. Permeation studies of indinavir across human cadaver skin resulted in enhanced transdermal flux from ethanolic liposomes that was significantly (P < 0.05) greater than that with ethanolic drug solution, conventional liposomes, or plain drug solution. Additionally, the ethanolic liposomes showed the shortest lag time for indinavir, thus presenting a suitable approach for transdermal delivery of this protease inhibitor. From the clinical editor: This study characterizes indinavir bearing ethanolic liposomes (ethosomes), and investigate their enhanced transdermal delivery potential, demonstrating a potentially a suitable approach for transdermal delivery of this protease inhibitor for HIV treatment, which typically has been associated with limited bioavailability via the oral route.


Assuntos
Etanol/química , Inibidores da Protease de HIV/administração & dosagem , Indinavir/administração & dosagem , Lipossomos/química , Administração Cutânea , Inibidores da Protease de HIV/química , Inibidores da Protease de HIV/farmacologia , Indinavir/farmacologia , Microscopia Eletrônica de Transmissão , Pele/metabolismo , Absorção Cutânea
6.
Nanomedicine ; 6(1): 110-8, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19446655

RESUMO

The aim of the present study was to evaluate two vesicular carrier systems, ethosomes and elastic liposomes loaded with hepatitis B surface antigen, for in vitro qualitative and quantitative uptake by human dendritic cells (DCs) and ability to stimulate T lymphocytes. Quantitative uptake of antigen-loaded carriers was documented by flow cytometry, and internalization of the systems by the DCs was studied using spectral bioimaging. Ability of antigen-pulsed DCs to stimulate autologous peripheral blood lymphocytes and levels of TH1/TH2 cytokines were also examined using flow cytometry. Both vesicular carrier systems as antigen delivery modules and DCs as antigen-presenting cells were able to generate a protective immune response. However, ethosomes were found to have higher internalizing ability and immunogenicity in comparison with elastic liposomes. These properties of ethosomes coupled with their skin-navigating potential, make it an attractive vehicle for development of a transcutaneous vaccine against hepatitis B in preference to elastic liposomes. FROM THE CLINICAL EDITOR: Two carrier systems for more potent vaccine administration - ethosomes and elastic liposomes loaded with hepatitis B surface antigen - are compared. Ethosomes demonstrated higher internalizing ability and immunogenicity. Due to their known skin-navigating potential, ethosomes may represent an attractive vehicle for development of a transcutaneous vaccine against hepatitis B.


Assuntos
Células Dendríticas/imunologia , Portadores de Fármacos/química , Antígenos de Superfície da Hepatite B/imunologia , Lipossomos/química , Animais , Apoptose , Bromodesoxiuridina/metabolismo , Bovinos , Núcleo Celular/metabolismo , Proliferação de Células , Citocinas/metabolismo , Elasticidade , Citometria de Fluxo , Fluoresceína-5-Isotiocianato/metabolismo , Humanos , Indóis/metabolismo , Cinética , Camundongos , Células NIH 3T3 , Necrose , Rodaminas/metabolismo , Soroalbumina Bovina/metabolismo , Células Th1/citologia , Células Th1/metabolismo , Células Th2/citologia , Células Th2/metabolismo , Fatores de Tempo
7.
Indian J Psychiatry ; 62(4): 370-378, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33165382

RESUMO

INTRODUCTION: To mitigate the spread of the pandemic coronavirus infection (COVID-19), governments across the world have adopted "lockdowns" which have confined many individuals to their homes. This disrupts normal life routines, elements of which are important circadian cues. The pandemic is also associated with new stressors, altered roles, and uncertainties about health and economic security, which are also likely to affect sleep. The current study is an online survey of sleep experience, routines, physical activity, and symptoms of anxiety and depression, to study the alterations associated with the lockdown. MATERIALS AND METHODS: The survey was conducted in early May 2020 using a questionnaire circulated through social media platforms. Questions related to demographic characteristics, current and previous sleep schedules, routine, and working patterns. Insomnia (Insomnia Severity Index - 4), Stress (Perceived Stress Scale - 4), anxiety and depressive symptoms (Patient Health Questionnaire - 4) and physical activity (International Physical Activities Questionnaire) were assessed using standardized instruments. RESULTS: A total of 958 valid responses were received. Compared to the prelockdown period, there was a shift to a later bedtime and waking time, with a reduction in night-time sleep and an increase in day-time napping. These effects were visible across occupational groups, but mostly affected working individuals except health professionals. Sleep quality deteriorated across groups. Reductions in sleep duration were associated with depressive symptoms. CONCLUSIONS: The COVID-19 lockdown is associated with changes in sleep schedule and in the quantity and quality of night-time sleep. Although these changes are associated with elevated rates of emotional symptoms, it is unclear from these cross-sectional results, whether sleep deterioration produces psychological distress, or vice versa.

8.
Nanomedicine ; 5(4): 432-42, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19341818

RESUMO

This work presents a novel cascade of chemical functionalization of multiwalled carbon nanotubes (MWCNTs) through chemical modification by a carbohydrate, D-galactose. Galactose-conjugated or galactosylated MWCNTs were synthesized involving the sequential steps of carboxylation, acylation, amine modification, and finally, galactose conjugation. The modification of MWCNTs with galactose was investigated by elemental analysis, x-ray diffraction analysis, Fourier transform-infrared spectroscopy, Raman spectroscopy, and zeta potential measurements, at every sequential step of functionalization. Size and surface characteristics of chemically modified MWCNTs were monitored by transmission electron microscopy and scanning electron microscopy. That galactosylation improved the dispersibility of MWCNTs in aqueous solvents was confirmed by investigation of their dispersion characteristics at different pH values. Thus, the galactosylated MWCNTs as developed could be used for delivery of different bioactive(s) as well as active ligand (galactose)-based targeting to hepatic tissue. FROM THE CLINICAL EDITOR: This work presents a novel cascade of functionalization of multiwalled carbon nanotubes (MWCNTs) through chemical modification by a carbohydrate. Galactosylation improves the dispersibility of MWCNTs in aqueous solvents. The galactosylated MWCNTs could be used for delivery of different bioactive(s) as well as active ligand-based targeting to hepatic tissue.


Assuntos
Galactose/química , Nanotubos de Carbono/química , Elementos Químicos , Nanotubos de Carbono/ultraestrutura , Espectroscopia de Infravermelho com Transformada de Fourier , Análise Espectral Raman , Temperatura , Fatores de Tempo , Difração de Raios X
10.
Crit Rev Ther Drug Carrier Syst ; 25(2): 169-206, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18540838

RESUMO

Carbon nanotubes (CNTs) are considered for use in numerous technological applications, including as biocompatible modules for the delivery of bioactives. However, there are unique properties of CNTs that limit their use as vehicles for various purposes. This review highlights the various challenges to a pharmaceutical scientist while exploring CNTs as bioactive delivery vehicles. The lack of solubility, nonbiodegradability, circulation half-life of 3-3.5 hours, biocompatibility, and immunogenicity limitations of CNTs are discussed in this review. These limitations indicate the need for modifications in order to explore the feasibility of CNTs as delivery vehicles.


Assuntos
Materiais Biocompatíveis , Nanotecnologia , Nanotubos de Carbono , Animais , Sistemas de Liberação de Medicamentos , Técnicas de Transferência de Genes , Meia-Vida , Humanos , Solubilidade , Vacinas/administração & dosagem
11.
Eur J Pharm Sci ; 33(4-5): 424-33, 2008 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-18359615

RESUMO

We have evaluated the efficiency of novel modified liposomes (ethosomes) for transcutaneous immunization (TCI) against Hepatitis B. Antigen-loaded ethosomes were prepared and characterized for shape, lamellarity, fluidity, size distribution, and entrapment efficiency. Spectral bio-imaging and flow cytometric studies showed efficient uptake of Hepatitis B surface antigen (HBsAg)-loaded ethosomes by murine dendritic cells (DCs) in vitro, reaching a peak by 180 min. Transcutaneous delivery potential of the antigen-loaded system using human cadaver skin demonstrated a much higher skin permeation of the antigen in comparison to conventional liposomes and soluble antigen preparation. Topically applied HBsAg-loaded ethosomes in experimental mice showed a robust systemic and mucosal humoral immune response compared to intramuscularly administered alum-adsorbed HBsAg suspension, topically applied plain HBsAg solution and hydroethanolic (25%) HBsAg solution. The ability of the antigen-pulsed DCs to stimulate autologous peripheral blood lymphocytes was demonstrated by BrdU assay and a predominantly TH1 type of immune response was observed by multiplex cytometric bead array analysis. HBsAg-loaded ethosomes are able to generate a protective immune response and their ability to traverse and target the immunological milieu of the skin may find a potential application in the development of a transcutaneous vaccine against Hepatitis B virus (HBV).


Assuntos
Antígenos de Superfície da Hepatite B/administração & dosagem , Vacinas contra Hepatite B/administração & dosagem , Imunização/métodos , Mucosa , Administração Cutânea , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Citocinas/imunologia , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/imunologia , Estabilidade de Medicamentos , Fibroblastos/efeitos dos fármacos , Fibroblastos/imunologia , Citometria de Fluxo , Vacinas contra Hepatite B/farmacocinética , Humanos , Imunoglobulina A/imunologia , Imunoglobulina G/imunologia , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/imunologia , Lipossomos , Camundongos , Camundongos Endogâmicos BALB C , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Mucosa/efeitos dos fármacos , Mucosa/imunologia , Pele/efeitos dos fármacos , Pele/imunologia , Pele/metabolismo , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia
12.
Curr Drug Deliv ; 5(3): 199-206, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18673263

RESUMO

In order to get across the intact skin, drug-laden carriers have to pass through narrow, confining pores of 50 nm or less diameter, under the influence of a suitable transdermal gradient. Novel ultradeformable carriers, the elastic liposomes achieve this target via its deforming and self-optimizing property. The main goal of this work was to prepare and characterize, elastic liposomes bearing melatonin, an anti-jet lag agent for its efficient transdermal delivery. Elastic liposomes bearing melatonin were prepared by modified extrusion method and characterized for shape, lamellarity, size distribution, percent drug loading, turbidity profile by Transmission electron microscopy (TEM), Dynamic light scattering (DLS), Mini-column centrifugation and Nephelometric techniques. The effect of different formulation variables like type of surfactant and concentration of surfactant on the deformability of vesicles, turbidity changes, transdermal flux across human cadaver skin, amount of drug deposited into the skin were investigated. Confocal laser scanning (CLS) micrographs revealed that probe (Rhodamine Red) loaded elastic liposomes were able to penetrate much deeper than the probe loaded conventional rigid liposomes. Out of the three surfactants utilized namely, Span 80, Sodium cholate and Sodium dodecylsulphate, formulation bearing Span 80 at an optimum lipid: surfactant ratio of 85:15% w/w proved to be the best in all parameters studied. The optimum skin permeation profile including greater transdermal flux and lower lag time of melatonin from optimized elastic liposomes via human cadaver skin was observed. Our results of the present study demonstrated the feasibility of elastic liposomal system for transdermal delivery of this anti- jet lag agent, which provides better transdermal flux, higher entrapment efficiency, greater skin drug deposition and possesses the ability of a self-penetration enhancer as compared to conventional liposomes.


Assuntos
Administração Cutânea , Síndrome do Jet Lag/tratamento farmacológico , Lipossomos , Melatonina/uso terapêutico , Absorção Cutânea/fisiologia , Química Farmacêutica , Cromatografia Líquida de Alta Pressão , Composição de Medicamentos , Elasticidade , Excipientes , Humanos , Técnicas In Vitro , Melatonina/administração & dosagem , Microscopia Confocal , Microscopia Eletrônica de Transmissão , Pele/ultraestrutura , Espectroscopia de Infravermelho com Transformada de Fourier
13.
Nanomedicine ; 4(3): 252-61, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18502187

RESUMO

Our aim in the present investigation was to develop a nanoparticulate carrier of amphotericin B (AmB) for controlled delivery as well as reduced toxicity. Nanoparticles of different gelatins (GNPs) (type A or B) were prepared by two-step desolvation method and optimized for temperature, pH, amount of cross-linker, and theoretical drug loading. AmB-loaded GNPs were characterized for size, polydispersity index (PI), shape, morphology, surface charge, drug release, and hemolysis. The developed GNPs (GNP(A300)) were found to be of nanometric size (213 +/- 10 nm), having low PI (0.092 +/- 0.015) and good entrapment efficiency (49.0 +/- 2.9%). All GNPs showed biphasic release characterized by an initial burst followed by controlled release. The in vivo hematological toxicity results suggest nonsignificant reduction (P > .05) in hemoglobin concentration and hematocrit. Nephrotoxicity results showed that there was a nonsignificant (P > .05) increase in blood urea nitrogen and serum creatinine levels. The results confirm that developed GNPs could optimize AmB delivery in terms of cost and safety, and type A gelatin with bloom number 300 was found suitable for such preparation.


Assuntos
Anfotericina B/química , Antifúngicos/química , Amidoidrolases/sangue , Anfotericina B/farmacologia , Anfotericina B/toxicidade , Animais , Antifúngicos/farmacologia , Antifúngicos/toxicidade , Nitrogênio da Ureia Sanguínea , Portadores de Fármacos , Gelatina , Hematócrito , Hemoglobinas/análise , Humanos , Técnicas In Vitro , Nefropatias/induzido quimicamente , Cinética , Masculino , Camundongos , Nanopartículas
14.
Expert Opin Drug Deliv ; 4(6): 579-93, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17970662

RESUMO

Human skin is a remarkably efficient barrier designed to keep our insides in and the outside out. The modulation of this efficient barrier's properties, including its permeability to chemicals, drugs and biologically active agents is the prime target for various dermal, transdermal, drug, antigen and gene delivery approaches. Therefore, several methods have been attempted to enhance the permeation rate of biologically active agents, temporarily and locally. One of the approaches is the application of drug-laden vesicular formulations. This review presents various mechanisms involved in increasing drug transport across the skin via different vesicular approaches, such as liposomes, elastic vesicles and ethosomes, along with compiling the research work conducted in this field.


Assuntos
Preparações Farmacêuticas/administração & dosagem , Absorção Cutânea , Pele/metabolismo , Administração Cutânea , Animais , Sistemas de Liberação de Medicamentos/métodos , Humanos , Lipossomos/química , Modelos Biológicos , Preparações Farmacêuticas/química , Preparações Farmacêuticas/metabolismo , Farmacocinética
15.
Eur J Pharm Biopharm ; 67(2): 398-405, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17452098

RESUMO

The current investigation aims to evaluate the transdermal potential of novel ethanolic liposomes (ethosomes) bearing Melatonin (MT), an anti-jet lag agent associated with poor skin permeation and long lag time. MT loaded ethosomes were prepared and characterized for vesicular shape and surface morphology, vesicular size, entrapment efficiency, stability, in vitro skin permeation and in vivo skin tolerability. Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), and Dynamic Light Scattering (DLS) defined ethosomes as spherical, unilamellar structures having low polydispersity (0.032+/-0.011) and nanometric size range (122+/-3.5 nm). % Entrapment efficiency of MT in ethosomal carrier was found to be 70.71+/-1.4. Stability profile of prepared system assessed for 120 days revealed very low aggregation and growth in vesicular size (7.6+/-1.2%). MT loaded ethosomal carriers also provided an enhanced transdermal flux of 59.2+/-1.22 microg/cm2/h and decreased lag time of 0.9 h across human cadaver skin. Fourier Transform-Infrared (FT-IR) data generated to assess the fluidity of skin lipids after application of formulation revealed a greater mobility of skin lipids on application of ethosomes as compared to that of ethanol or plain liposomes. Skin permeation profile of the developed formulation further assessed by confocal laser scanning microscopy (CLSM) revealed an enhanced permeation of Rhodamine Red (RR) loaded formulations to the deeper layers of the skin (240 microm). Further, a better skin tolerability of ethosomal suspension on rabbit skin suggested that ethosomes may offer a suitable approach for transdermal delivery of melatonin.


Assuntos
Administração Cutânea , Etanol/química , Lipídeos/química , Lipossomos/química , Melatonina/química , Pele/efeitos dos fármacos , Calorimetria , Cromatografia Líquida de Alta Pressão , Humanos , Microscopia Confocal , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Fosfatidilcolinas/química , Pele/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier , Fatores de Tempo
16.
J Pharm Sci ; 96(1): 145-55, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16960826

RESUMO

One major problem encountered in transdermal drug delivery is the low permeability of drugs through the skin barrier. In the present investigation ultradeformable lipid vesicles, that is, elastic liposomes were prepared incorporating propranolol hydrochloride for enhanced transdermal delivery. Elastic liposomes bearing propranolol hydrochloride were prepared by conventional rotary evaporation method and characterized for various parameters including vesicles shape and surface morphology, size and size distribution, entrapment efficiency, elasticity, turbidity, and in vitro drug release. In vitro flux, enhancement ratio (ER), and release pattern of propranolol hydrochloride were calculated for transdermal delivery. In vivo study conducted on male albino rats (Sprague Dawley) was also taken as a measure of performance of elastic liposomal, liposomal, and plain drug solution. The better permeation through the skin was confirmed by confocal laser scanning microscopy (CLSM). Results indicate that the elastic liposomal formulation for transdermal delivery of propranolol hydrochloride provides better transdermal flux, higher entrapment efficiency, ability as a self-penetration enhancer and effectiveness for transdermal delivery as compared to liposomes.


Assuntos
Anti-Hipertensivos/administração & dosagem , Lipossomos , Fosfolipídeos/química , Propranolol/administração & dosagem , Absorção Cutânea , Administração Cutânea , Animais , Anti-Hipertensivos/sangue , Anti-Hipertensivos/farmacocinética , Química Farmacêutica , Cultura em Câmaras de Difusão , Composição de Medicamentos/métodos , Elasticidade , Humanos , Cinética , Masculino , Fluidez de Membrana , Microscopia Confocal , Técnicas de Cultura de Órgãos , Tamanho da Partícula , Permeabilidade , Propranolol/sangue , Propranolol/farmacocinética , Ratos , Ratos Sprague-Dawley , Solubilidade , Propriedades de Superfície , Tensoativos/química
17.
Biomaterials ; 27(18): 3491-6, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16513163

RESUMO

Melatonin (MT) is a good candidate for transdermal delivery considering its short biological half-life, low molecular weight and a variable oral absorption. The objective of this work was to develop a novel formulation of melatonin for its efficient transdermal delivery. Melatonin loaded elastic liposomal formulation was prepared, characterized and the effect of this developed formulation on the in vitro permeation of melatonin across human cadaver skin was investigated, using a locally fabricated Franz diffusion cell. Skin permeation potential of the developed formulation was assessed using confocal laser scanning microscopy (CLSM), which revealed an enhanced permeation of the formulation to the deeper layers of the skin (up to 180 microm) following channel like pathways. Skin permeation profile of melatonin through elastic liposomal formulations was observed and the investigations revealed an enhanced transdermal flux (51.2+/-2.21 microg/cm(2)/h), decreased lag time (1.1h) and an optimum permeability coefficient (15.06+/-0.52 cm/h) for melatonin. The obtained flux was nearly 5 and 12.3 times higher than conventional liposomal and plain drug solution, respectively (P<0.005). Our result suggests the feasibility of elastic liposomal system for transdermal delivery of melatonin thereby eliminating the limitations of long lag time and poor skin permeation associated with the drug.


Assuntos
Melatonina/administração & dosagem , Administração Cutânea , Cadáver , Hormônios/administração & dosagem , Humanos , Lipossomos , Permeabilidade , Glândula Pineal/metabolismo , Pele/metabolismo , Absorção Cutânea
18.
Indian Heart J ; 58(4): 336-40, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-19039151

RESUMO

AIM: Hypertension is known to induce many pathological changes in the body, including cardiac hypertrophy, atherosclerosis, micro-aneurisms and stroke. Besides these conspicuous pathologies, it also has subtle effects on the functioning of the brain. These cognitive changes have received little attention despite the fact that they make a large impact on the daily functioning of affected persons. The present study was conducted to assess the effect of hypertension and related factors on cognitive functions in an Indian population. METHODS AND RESULTS: A cohort of young hypertensive subjects was recruited after obtaining informed consent. Subjects with confounding factors, such as substance use, neurological disorders, endocrinopathies, inflammatory conditions and psychiatric illnesses, were excluded. The average systolic and diastolic blood pressure of the subjects since the onset of illness and prescription of drugs were noted from the records. Compliance was assessed with the help of information given by the subjects and their close relatives. The mini-mental state examination and a battery of neuropsychological tests (digit span test, trail making test, Stroop test, visuospatial working memory matrix and word fluency test) were applied to all participants. Univariate regression analysis was used for the assessment of association and a one-way analysis of variance was performed on categorical variables. The mean age of the subjects was 52 years, and the average duration of hypertension 9 years. Twelve subjects had dementia which could be attributed to the subtle effects of hypertension only. Blood pressure (both systolic and diastolic) had a significant negative association with the cognitive tests. Cognitive impairment was also seen in subjects who reported poor drug compliance and those using beta blockers, while calcium channel blockers played a protective role. CONCLUSIONS: Hypertension was associated with a significant decline in cognitive functioning in younger subjects. Good compliance with drugs and the use of calcium channel blockers had a protective effect on hypertension-induced cognitive decline.


Assuntos
Demência/epidemiologia , Hipertensão/epidemiologia , Adulto , Pressão Sanguínea/fisiologia , Cognição/fisiologia , Comorbidade , Demência/prevenção & controle , Feminino , Humanos , Hipertensão/tratamento farmacológico , Masculino , Pessoa de Meia-Idade
19.
Ind Psychiatry J ; 23(2): 134-42, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25788803

RESUMO

CONTEXT: Diabetes affects 9.2% of adults in India. About 8-16% of its population also suffer from depression. Both diseases pose a serious health challenge at individual and system level. The prevalence of depression in diabetes is much higher than in the general population. Undiagnosed and untreated depression puts people at higher morbidity and mortality risk. AIM: To study the prevalence of depression in diabetes and to identify associated risk factors. SETTINGS AND DESIGN: Case control study carried out in an outpatient setting of a tertiary hospital in central India. MATERIALS AND METHODS: One hundred and nine type 2 diabetes patients and 91 healthy controls formed the subjects of the study. Sociodemographic data were obtained on seven parameters. Comprehensive clinical data were obtained by means of standard procedures. Blood sugar levels and glycosylated hemoglobin levels were measured to assess glycemic control. Data of diabetic patients and controls as well as that of depressed and nondepressed diabetics were subjected to statistical analysis. RESULTS: About 42.2% of diabetes patients and only 4.39% of controls had depression. About 19% of diabetics had peripheral neuropathy but had much higher neuropathic symptoms. Depression was not related to any sociodemographic or clinical factors but was strongly associated with poor glycemic control. CONCLUSION: Depression is highly prevalent in diabetes. Physical symptoms mask depression. Special attention needs to be paid to diagnose depression in diabetes and treat it appropriately along with effective glycemic control. Diabetes patients need to be treated collaboratively by physicians and psychiatrists.

20.
Chem Biol Drug Des ; 80(4): 598-604, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22716235

RESUMO

Some hybrid 1,3,4-thiadiazole-1,3,5-triazine derivatives tethered via -S- bridge were synthesized and characterized with the aid of spectroscopic and elemental analysis. These hybrid conjugates were then investigated for their antibacterial activity against selected Gram-positive and Gram-negative bacteria. Excellent to moderate antibacterial activity was presented by the target compounds.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Tiadiazóis/química , Tiadiazóis/farmacologia , Triazinas/química , Triazinas/farmacologia , Antibacterianos/síntese química , Bactérias/efeitos dos fármacos , Infecções Bacterianas/tratamento farmacológico , Humanos , Tiadiazóis/síntese química , Triazinas/síntese química
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