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1.
BMC Oral Health ; 24(1): 445, 2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38609921

RESUMO

BACKGROUND: Considering the extensive use of bleaching agents and the occurrence of side effects such as enamel demineralization, this study aimed to assess the enamel changes of bleached teeth following the experimental application of chitosan-bioactive glass (CH-BG). METHODS: In this in vitro study, CH-BG (containing 66% BG) was synthesized and characterized by Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). Thirty sound human premolars were bleached with 40% hydrogen peroxide, and the weight% of calcium and phosphorus elements of the buccal enamel surface was quantified before and after bleaching by scanning electron microscopy/ energy-dispersive X-ray spectroscopy (SEM, EDX). Depending on the surface treatment of the enamel surface, the specimens were divided into three groups (n = 10): control (no treatment), MI Paste (MI), and CH-BG. Then the specimens were stored in artificial saliva for 14 days. The SEM/EDX analyses were performed again on the enamel surface. Data were analyzed by one-way ANOVA and Tukey's test and a p-value of < 0.05 was considered statistically significant. RESULTS: In all groups, the weight% of calcium and phosphorus elements of enamel decreased after bleaching; this reduction was significant for phosphorus (p < 0.05) and insignificant for calcium (p > 0.05). After 14 days of remineralization, the weight% of both calcium and phosphorus elements was significantly higher compared to their bleached counterparts in both MI and CH-BG groups (p < 0.05). Following the remineralization process, the difference between MI and CH-BG groups was not significant (p > 0.05) but both had a significant difference with the control group in this regard (p < 0.05). CONCLUSIONS: The synthesized CH-BG compound showed an efficacy comparable to that of MI Paste for enamel remineralization of bleached teeth.


Assuntos
Quitosana , Clareamento Dental , Humanos , Cálcio , Quitosana/efeitos adversos , Clareamento Dental/efeitos adversos , Esmalte Dentário , Fósforo
2.
Int J Pharm ; 653: 123929, 2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38387817

RESUMO

Oxidative stress plays a crucial role in steroid-induced osteonecrosis of the femoral head (SONFH). Although several antioxidant strategies have been investigated for treating SONFH, their antioxidant efficiencies and therapeutic effects remain unsatisfactory. Here, we developed a selenium nanoparticles/carboxymethyl chitosan/alginate (SeNPs/CMC/Alg) antioxidant hydrogel and evaluated its ability to treat SONFH. In vitro assays indicated that the SeNPs/CMC/Alg hydrogel exhibited excellent properties, such as low cytotoxicity, sustained SeNPs release, and favorable antioxidant activity. Under oxidative stress, the SeNPs/CMC/Alg hydrogel promoted reactive oxygen species (ROS) elimination and enhanced the osteogenic and proangiogenic abilities of bone marrow mesenchymal stem cells (BMSCs). After establishing a rabbit model of SONFH, the SeNPs/CMC/Alg hydrogel was transplanted into the femoral head after core decompression (CD) surgery. Radiographic and histological analyses revealed that the hydrogel treatment alleviated SONFH by eliminating ROS and promoting osteogenesis and angiogenesis compared to those in the CD and CMC/Alg groups. In vitro and in vivo studies indicated that the Wnt/ß-catenin signaling pathway was activated by the SeNPs/CMC/Alg hydrogel in both hydrogen peroxide-conditioned BMSCs and necrotic femoral heads. These findings indicate that local transplantation of the SeNPs/CMC/Alg hydrogel is beneficial for treating SONFH, as it promotes ROS elimination and activation of the Wnt/ß-catenin signaling pathway.


Assuntos
Quitosana , Nanopartículas , Osteonecrose , Selênio , Animais , Coelhos , Antioxidantes , Selênio/farmacologia , Cabeça do Fêmur/patologia , Espécies Reativas de Oxigênio , Alginatos/efeitos adversos , Quitosana/efeitos adversos , Hidrogéis/efeitos adversos , Osteonecrose/induzido quimicamente , Osteonecrose/tratamento farmacológico , Osteonecrose/patologia , Esteroides
3.
J Cosmet Dermatol ; 21(9): 4001-4008, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34965006

RESUMO

INTRODUCTION: The bioactivities of green tea extract were indicated to promote skin health in vitro. Few clinical studies reported on skin nourishment of topical applying green tea extract due to the limited skin absorption. METHODS: This current study evaluated the clinical effectiveness and safety of green tea extract encapsulated chitosan microparticles (GTP) in emulsion base on a split-face, double-blind, randomized placebo-controlled study. Twenty-nine female volunteers were recruited into the study. They were randomly assigned to apply GTP and placebo creams on each half face for 8 weeks. The facial skin properties on both sides were monitored and evaluated every 2 weeks. RESULTS: The results revealed that skin elasticity (R2) of half face treated with GTP cream (0.748 ± 0.05) was superior to another that received placebo cream (0.722 ± 0.05) at 4th week. In addition, melanin index implying skin dullness of the half face that received GTP cream significantly improved within the 6th week after application (placebo =295.60 ± 58.81, GTP =282.70 ± 59.62). Most importantly, the photographs clearly indicated that the decreasing in facial wrinkles of volunteers applied with GTP cream was more than those applying placebo cream. Signs of skin irritation were not evident in both treatment and placebo cream groups. CONCLUSION: Based on study outcomes, the green tea extract encapsulated chitosan microparticles appear to be the promising active candidate for promoting skin elasticity and improving skin dullness and wrinkles.


Assuntos
Quitosana , Envelhecimento da Pele , Antioxidantes , Quitosana/efeitos adversos , Método Duplo-Cego , Emolientes , Emulsões , Feminino , Guanosina Trifosfato , Humanos , Melaninas , Extratos Vegetais/efeitos adversos , Chá
4.
Br J Nutr ; 126(11): 1651-1662, 2021 12 14.
Artigo em Inglês | MEDLINE | ID: mdl-33550994

RESUMO

An 8-week feeding experiment was conducted to investigate and confront the putative functions of chitosan (CTS) and chitooligosaccharide (COS) in the growth and homoeostasis of distal intestine in juvenile turbots fed diets containing soyabean meal (SBM). Three isolipidic and isonitrogenous diets were formulated by supplemented basal diet (based on a 400 g/kg SBM) with 7·5 g/kg CTS or with 2·0 g/kg COS. Our results indicated that both CTS and COS supplementation could significantly improve (i) the growth performance and feed efficiency ratio; (ii) antioxidant activity driven by metabolic enzymes (i.e. catalase, glutathione reductase, glutathione peroxidase and superoxide dismutase); (iii) glutathione levels; (iv) acid phosphatase and lysozyme activity and (v) IgM content. As a result, these two particular prebiotics were able to significantly attenuate the histological alterations due to local inflammation as well as to decrease the transcriptional levels of proinflammatory cytokines (i.e. IL-1ß, IL-8 and TNF-α) and major pathway effectors (i.e. activator protein-1 (AP-1), NF-кB, p38 mitogen-activated protein kinase, c-Jun N-terminal kinase and extracellular regulated kinase). High-throughput sequencing data indicated that dietary CTS and COS could significantly decrease the diversity of intestinal bacteria but elevate the relative abundances of Bacillus, Lactobacillus and Pseudomonas genera. Altogether, these findings suggest that CTS and COS can improve growth of turbot, enhance intestinal immune and anti-oxidant systems and promote the balance of intestinal microbiota. The protective effects, elicited by these two prebiotics, against SBM-induced inflammation could be attributed to their roles in alleviating the overexpression of inflammatory cytokines by possibly down-regulating NF-кB, AP-1 and/or mitogen-activated protein kinases pathways.


Assuntos
Quitosana , Linguados , Ração Animal/análise , Animais , Quitosana/efeitos adversos , Dieta , Suplementos Nutricionais , Inflamação/induzido quimicamente , Proteínas Quinases Ativadas por Mitógeno , NF-kappa B , Oligossacarídeos , Fator de Transcrição AP-1
5.
Nutr Cancer ; 73(11-12): 2347-2362, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32972241

RESUMO

This study aimed to investigate the impact of ginger extract (GE) loaded into chitosan nanoparticles (CNPs) in enhancing cytotoxicity and reducing cardiotoxicity of doxorubicin (DXN) in hepatocellular carcinoma (HCC) induced mice. DXN and GE were loaded into CNPs and cytotoxicity of loaded and unloaded drugs against HepG2 cells was evaluated. HCC was induced in male albino mice by injection of diethylnitrosamine (DINA). Mice were divided into eight groups (n = 15): (1) normal control, (2) DINA, (3) CNPs, (4) free DXN, (5) CNPs DXN, (6) free GE, (7) CNPs GE, and (8) CNPs DXN + CNPs GE. Both GE and DXN loaded into CNPs showed a greater decline in cell viability of HepG2 cells than the unloaded forms. GE CNPs displayed pronounced anticancer activity In Vivo through apoptosis, greater down-regulation of multidrug resistance 1, enhancement of anti-oxidant activity and depletion of vascular endothelial growth factor content in liver tissues. GE CNPs in combination with DXN CNPs showed nearly normal hepatic lobule architecture and the greatest increase in apoptotic cell count. Co-treatment group had decreased cardiac malondialdehyde, tumor necrosis factor-α and serum activity of creatine kinase and lactate dehydrogenase. Combination of GE CNPs and DXN CNPs might be a potentially effective therapeutic approach for HCC.


Assuntos
Carcinoma Hepatocelular , Quitosana , Neoplasias Hepáticas , Nanopartículas , Animais , Carcinoma Hepatocelular/patologia , Cardiotoxicidade , Quitosana/efeitos adversos , Doxorrubicina/toxicidade , Zingiber officinale , Neoplasias Hepáticas/induzido quimicamente , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/metabolismo , Masculino , Camundongos , Extratos Vegetais , Fator A de Crescimento do Endotélio Vascular
6.
Mol Nutr Food Res ; 62(8): e1700842, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29451712

RESUMO

SCOPE: We performed a pooled analysis with trial sequential analysis (TSA) to evaluate the efficacy and safety of chitosan supplementation on serum lipids in humans. METHODS AND RESULTS: Medline, EMBASE, and CENTRAL databases were queried. Impact was expressed as a weighted mean difference (WMD) and 95% confidence interval (CI). Sensitivity analysis was conducted using the leave-one-out method. Statistical heterogeneity, publication bias, TSA, and subgroup analyses were also assessed. Fourteen trials (21 treatment arms) encompassing 1108 participants were suitable for statistical pooling. Chitosan supplementation significantly improved the total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) concentrations in all patients. The WMDs were -0.20 mmol L-1 (95% CI, -0.35 to -0.05; p = 0.009) for TC, and -0.20 mol L-1 (95% CI, -0.26 to -0.15; p = 0.0001) for LDL-C, respectively. TSA demonstrated that the cumulative Z-curve crossed the trial sequential monitoring boundary for benefit providing conclusive evidence for the benefit of chitosan. However, no significant changes were seen with high-density lipoprotein cholesterol (HDL-C) and triglycerides. Our findings were robust after sensitivity analyses, and no serious adverse events were reported with chitosan intake. CONCLUSION: Supplementation with chitosan effectively reduces plasma concentrations of TC and LDL-C. Current evidence indicates daily chitosan supplementation as a candidate for therapeutic lipid management strategies.


Assuntos
Anticolesterolemiantes/uso terapêutico , Quitosana/uso terapêutico , Suplementos Nutricionais , Medicina Baseada em Evidências , Hipercolesterolemia/terapia , Adulto , Anticolesterolemiantes/efeitos adversos , Biomarcadores/sangue , Quitosana/efeitos adversos , Suplementos Nutricionais/efeitos adversos , Humanos , Hipercolesterolemia/sangue , Ensaios Clínicos Controlados Aleatórios como Assunto
7.
Drug Des Devel Ther ; 12: 67-75, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29343944

RESUMO

BACKGROUND: Chitosan is a popular dietary fiber often used to reduce dietary fat absorption to control weight and blood lipids. However, its effects on blood pressure (BP) have not been fully elucidated. We evaluated the effects of chitosan administration on systolic blood pressure (SBP) and diastolic blood pressure (DBP) through a pooled analysis of available randomized controlled trials (RCTs). MATERIALS AND METHODS: Electronic searches were conducted in Medline, Cochrane Library, Scopus, and EMBASE to identify relevant human placebo-control RCTs. Trials that reported BP changes from baseline to study endpoint in patients receiving treatment of chitosan were included for analysis. Weighted mean difference (WMD) and 95% CIs were pooled using fixed-effects or random-effects models. Statistical heterogeneity, prespecified subgroup, publication bias, sensitivity analysis, and meta-regression assessments were also tested. RESULTS: Six hundred and seventeen participants from eight trials with 10 arms were included. Overall, chitosan administration did not significantly lower SBP (WMD: -1.41 mmHg, 95% CI: -3.29 to 0.47; P=0.14) and DBP (WMD: -0.61 mmHg, 95% CI: -1.75 to 0.52; P=0.29). However, our subgroup analyses indicated that chitosan consumption significantly reduced DBP in shorter-term (<12 weeks) and higher-dose (>2.4 g/day) arms. Funnel plots or Egger's tests analysis (P=0.36 and 0.43 for SBP and DBP, respectively) demonstrated that there was no significant publication bias in this study. CONCLUSION: This meta-analysis indicates that chitosan consumption significantly decreases DBP at higher dosage and in shorter-term interventions, while chitosan has no significant effects on SBP. However, these results should be interpreted cautiously because of the limited eligible RCTs included in this meta-analysis; further large-scale, well-designed RCTs on this topic are urgently needed.


Assuntos
Pressão Sanguínea , Quitosana/administração & dosagem , Fibras na Dieta/administração & dosagem , Suplementos Nutricionais , Hipertensão/dietoterapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Quitosana/efeitos adversos , Diástole , Fibras na Dieta/efeitos adversos , Suplementos Nutricionais/efeitos adversos , Medicina Baseada em Evidências , Humanos , Hipertensão/diagnóstico , Hipertensão/fisiopatologia , Pessoa de Meia-Idade , Ensaios Clínicos Controlados Aleatórios como Assunto , Sístole , Fatores de Tempo , Resultado do Tratamento , Adulto Jovem
8.
J Biomater Appl ; 31(5): 708-720, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27789793

RESUMO

In the present study, polyurethane materials were obtained from castor oil, polycaprolactone and isophorone diisocyanate by incorporating different concentrations of chitosan (0.5, 1.0 and 2.0% w/w) as an additive to improve the mechanical properties and the biological activity of polyurethanes. The polyurethanes were characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, stress/strain fracture tests and swelling analysis, and the hydrophilic character of the surface was determined by contact angle trials. The objectives of the study were to evaluate the effect of the incorporation of chitosan on the changes of the physico-chemical and mechanical properties and the in vitro biological activity of the polyurethanes. It was found that the incorporation of chitosan enhances the ultimate tensile strength of the polyurethanes and does not affect the strain at fracture in polyurethanes with 5% w/w of polycaprolactone and concentrations of chitosan ranging from 0 to 2% w/w. In addition, PCL5-Q-PU formulations and their degradation products did not affect cell viability of L929 mouse fibroblast and 3T3, respectively. Polyurethane formulations showed antibacterial activities against Staphylococcus aureus and Escherichia coli bacteria. The results of this study have highlighted the potential biomedical application of this polyurethanes related to soft and cardiovascular tissues.


Assuntos
Materiais Biocompatíveis/síntese química , Óleo de Rícino/química , Sobrevivência Celular/efeitos dos fármacos , Quitosana/química , Poliésteres/química , Poliuretanos/efeitos adversos , Poliuretanos/síntese química , Células 3T3 , Implantes Absorvíveis , Animais , Materiais Biocompatíveis/efeitos adversos , Óleo de Rícino/efeitos adversos , Quitosana/efeitos adversos , Força Compressiva , Teste de Materiais , Camundongos , Poliésteres/efeitos adversos , Estresse Mecânico , Resistência à Tração
9.
Mol Pharm ; 13(10): 3578-3589, 2016 10 03.
Artigo em Inglês | MEDLINE | ID: mdl-27589087

RESUMO

The continuous rise of antimicrobial resistance and the dearth of new antibiotics in the clinical pipeline raise an urgent call for the development of potent antimicrobial agents. Cationic chitosan derivatives, N-(2-hydroxypropyl)-3-trimethylammonium chitosan chlorides (HTCC), have been widely studied as potent antibacterial agents. However, their systemic structure-activity relationship, activity toward drug-resistant bacteria and fungi, and mode of action are very rare. Moreover, toxicity and efficacy of these polymers under in vivo conditions are yet to be established. Herein, we investigated antibacterial and antifungal efficacies of the HTCC polymers against multidrug resistant bacteria including clinical isolates and pathogenic fungi, studied their mechanism of action, and evaluated cytotoxic and antimicrobial activities in vitro and in vivo. The polymers were found to be active against both bacteria and fungi (MIC = 125-250 µg/mL) and displayed rapid microbicidal kinetics, killing pathogens within 60-120 min. Moreover, the polymers were shown to target both bacterial and fungal cell membrane leading to membrane disruption and found to be effective in hindering bacterial resistance development. Importantly, very low toxicity toward human erythrocytes (HC50 = >10000 µg/mL) and embryo kidney cells were observed for the cationic polymers in vitro. Further, no inflammation toward skin tissue was observed in vivo for the most active polymer even at 200 mg/kg when applied on the mice skin. In a murine model of superficial skin infection, the polymer showed significant reduction of methicillin-resistant Staphylococcus aureus (MRSA) burden (3.2 log MRSA reduction at 100 mg/kg) with no to minimal inflammation. Taken together, these selectively active polymers show promise to be used as potent antimicrobial agents in topical and other infections.


Assuntos
Anti-Infecciosos/uso terapêutico , Quitosana/análogos & derivados , Compostos de Amônio Quaternário/química , Compostos de Amônio Quaternário/uso terapêutico , Animais , Anti-Infecciosos/administração & dosagem , Anti-Infecciosos/efeitos adversos , Sobrevivência Celular/efeitos dos fármacos , Quitosana/efeitos adversos , Quitosana/química , Quitosana/uso terapêutico , Farmacorresistência Fúngica , Farmacorresistência Bacteriana Múltipla , Feminino , Humanos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/patogenicidade , Camundongos , Camundongos Endogâmicos BALB C , Testes de Sensibilidade Microbiana , Compostos de Amônio Quaternário/efeitos adversos , Infecções Cutâneas Estafilocócicas/tratamento farmacológico , Relação Estrutura-Atividade
10.
J Sci Food Agric ; 96(13): 4505-13, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26869236

RESUMO

BACKGROUND: Oregano essential oil (EO) was incorporated into film-forming dispersions (FFDs) based on biopolymers (chitosan and/or methylcellulose) at two different concentrations. The effect of the application of the FFDs was evaluated on tomato plants (cultivar Micro-Tom) at three different stages of development, and on pre-harvest and postharvest applications on tomato fruit. RESULTS: The application of the FFDs at '3 Leaves' stage caused phytotoxic problems, which were lethal when the EO was applied without biopolymers. Even though plant growth and development were delayed, the total biomass and the crop yield were not affected by biopolymer-EO treatments. When the FFDs were applied in the 'Fruit' stage the pre-harvest application of FFDs had no negative effects. All FFDs containing EO significantly reduced the respiration rate of tomato fruit and diminished weight loss during storage. Moreover, biopolymer-EO FFDs led to a decrease in the fungal decay of tomato fruit inoculated with Rhizopus stolonifer spores, as compared with non-treated tomato fruit and those coated with FFDs without EO. CONCLUSION: The application of biopolymer-oregano essential oil coatings has been proven to be an effective treatment to control R. stolonifer in tomato fruit. © 2016 Society of Chemical Industry.


Assuntos
Biopolímeros/química , Proteção de Cultivos , Conservação de Alimentos , Frutas/química , Óleos Voláteis/química , Origanum/química , Óleos de Plantas/química , Solanum lycopersicum/química , Biopolímeros/efeitos adversos , Respiração Celular , Quitosana/efeitos adversos , Quitosana/química , Produtos Agrícolas/química , Produtos Agrícolas/crescimento & desenvolvimento , Produtos Agrícolas/microbiologia , Emulsões , Flores/química , Flores/crescimento & desenvolvimento , Flores/metabolismo , Flores/microbiologia , Qualidade dos Alimentos , Armazenamento de Alimentos , Frutas/crescimento & desenvolvimento , Frutas/metabolismo , Frutas/microbiologia , Concentração de Íons de Hidrogênio , Solanum lycopersicum/crescimento & desenvolvimento , Solanum lycopersicum/metabolismo , Solanum lycopersicum/microbiologia , Metilcelulose/efeitos adversos , Metilcelulose/química , Viabilidade Microbiana , Óleos Voláteis/efeitos adversos , Origanum/efeitos adversos , Pigmentos Biológicos/análise , Pigmentos Biológicos/biossíntese , Folhas de Planta/química , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Folhas de Planta/microbiologia , Óleos de Plantas/efeitos adversos , Rhizopus/crescimento & desenvolvimento , Rhizopus/isolamento & purificação , Rhizopus/fisiologia , Esporos Fúngicos/crescimento & desenvolvimento , Esporos Fúngicos/isolamento & purificação , Esporos Fúngicos/fisiologia , Propriedades de Superfície
11.
Meat Sci ; 111: 192-7, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26473294

RESUMO

Chitosan coatings, with and without clove oil, were investigated for effects on quality and shelf life of cooked pork sausages stored at a refrigerated temperature (4±2°C). The various treatments of cooked pork sausages were: untreated (control), coating with 2% chitosan (CS), and coating with a mixture having 2% chitosan and 1.5% clove oil (CS+CO). Various microbiological, physical, chemical and sensory properties were monitored over 25 days of storage. The total viable count, the psychrotrophic bacteria count, the L* value, peroxide value and the thiobarbituric acid reactive substances increased, while the a* value, the b* value, the pH and the sensory scores decreased with storage time, across all treatments. However, these changes were slowest with the CS+CO treatment. Based on sensory evaluation and microbiological quality, the shelf lives were 14 days for control, 20 days for CS, and 20 days for CS+CO treated samples, under refrigerated storage.


Assuntos
Quitosana/química , Óleo de Cravo/química , Fast Foods/análise , Conservação de Alimentos , Qualidade dos Alimentos , Armazenamento de Alimentos , Produtos da Carne/análise , Animais , Fenômenos Químicos , Quitosana/efeitos adversos , Óleo de Cravo/efeitos adversos , Culinária , Fast Foods/microbiologia , Bactérias Gram-Negativas/crescimento & desenvolvimento , Bactérias Gram-Negativas/isolamento & purificação , Bactérias Gram-Positivas/crescimento & desenvolvimento , Bactérias Gram-Positivas/isolamento & purificação , Humanos , Concentração de Íons de Hidrogênio , Peroxidação de Lipídeos , Reação de Maillard , Produtos da Carne/microbiologia , Viabilidade Microbiana , Refrigeração , Sensação , Propriedades de Superfície , Sus scrofa , Tailândia
12.
Carbohydr Polym ; 121: 403-10, 2015 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-25659715

RESUMO

In the present study, nanoparticles of low MW chitosan (CS) were formulated in which measles antigen was entrapped and subsequently coated with sodium alginate. The size and surface properties of the nanoparticle can be tuned with different MW of CS. In vitro release studies showed initial burst release followed by extended release, best fitted in the Makoid-Banakar model (R(2)>0.98). SDS-PAGE assay revealed that alginate coating could effectively protect antigen in acidic condition for at least 2h. Cell viability was assessed using MTT assay into HT 29 cell line. Formulations were orally administered to mice and immunological responses were evaluated using ELISA method. Obtained results showed that measles antigen-loaded CS nanoparticles induced strong immune response and significant correlation was observed between the immune response with CS MW. Protecting ability of antigen in gastric environment, sustained release kinetics, systemic and mucosal immune responses and low cytotoxicity observed for the alginate coated nanoparticles demonstrated that LMW CS could be promising platform for oral vaccine delivery.


Assuntos
Alginatos/química , Quitosana/química , Vacina contra Sarampo/química , Nanopartículas/química , Administração Oral , Alginatos/efeitos adversos , Animais , Quitosana/efeitos adversos , Ácido Glucurônico/efeitos adversos , Ácido Glucurônico/química , Células HT29 , Ácidos Hexurônicos/efeitos adversos , Ácidos Hexurônicos/química , Humanos , Vacina contra Sarampo/administração & dosagem , Camundongos , Peso Molecular , Nanopartículas/efeitos adversos
13.
Angiology ; 66(5): 416-21, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25037700

RESUMO

Lipid-lowering drugs may cause adverse effects and, although lipid targets may be achieved, a substantial residual cardiovascular (CV) risk remains. Treatment with agents mimicking proteins present in the body, such as incretin-based therapies, provided promising results. However, in order to improve lipids and CV risk, lifestyle measures remain important. Some researchers focused on nutraceuticals that may beneficially affect metabolic parameters and minimize CV risk. Chitosan, a dietary fiber, can regulate lipids with benefit on anthropometric parameters. The beneficial properties of dietary supplements (such as green tea extract, prebiotics, plant sterols, and stanols) on plasma lipids, lipoproteins, blood pressure, glucose, and insulin levels and their anti-inflammatory and anti-oxidant effects are documented. However, larger, prospective clinical trials are required to confirm such benefits. Such treatments may be recommended when lipid-lowering drugs are neither indicated nor tolerated as well as in order to achieve therapeutic targets and/or overcome residual CV risk.


Assuntos
Doenças Cardiovasculares/prevenção & controle , Quitosana/administração & dosagem , Fibras na Dieta/administração & dosagem , Suplementos Nutricionais , Dislipidemias/tratamento farmacológico , Hipolipemiantes/administração & dosagem , Lipídeos/sangue , Animais , Biomarcadores/sangue , Doenças Cardiovasculares/etiologia , Quitosana/efeitos adversos , Fibras na Dieta/efeitos adversos , Suplementos Nutricionais/efeitos adversos , Dislipidemias/sangue , Dislipidemias/complicações , Dislipidemias/diagnóstico , Humanos , Hipolipemiantes/efeitos adversos , Fatores de Risco , Resultado do Tratamento
14.
Hum Vaccin Immunother ; 10(3): 797-807, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24346613

RESUMO

The nasal route is attractive for the delivery of vaccines in that it not only offers an easy to use, non-invasive, needle-free alternative to more conventional parenteral injection, but it also creates an opportunity to elicit both systemic and (crucially) mucosal immune responses which may increase the capability of controlling pathogens at the site of entry. Immune responses to "naked" antigens are often modest and it is widely accepted that incorporation of an adjuvant is a prerequisite for the achievement of clinically effective nasal vaccines. Many existing adjuvants are sub-optimal or unsuitable because of local toxicity or poor enhancement of immunogenicity. Chitosan, particularly chitosan salts, have now been used in several preclinical and clinical studies with good tolerability, excellent immune stimulation and positive clinical results across a number of infections. Particularly significant evidence supporting chitosan as an adjuvant for nasal vaccination comes from clinical investigations on a norovirus vaccine; this demonstrated the ability of chitosan (ChiSys®), when combined with monophosphoryl lipid, to evoke robust immunological responses and confer protective immunity following (enteral) norovirus challenge. This article summarizes the totality of the meaningful information (including key unpublished data) supporting the development of chitosan-adjuvanted vaccines.


Assuntos
Adjuvantes Imunológicos/administração & dosagem , Adjuvantes Imunológicos/farmacologia , Quitosana/administração & dosagem , Quitosana/farmacologia , Adjuvantes Imunológicos/efeitos adversos , Administração Intranasal , Quitosana/efeitos adversos , Ensaios Clínicos como Assunto , Avaliação Pré-Clínica de Medicamentos , Humanos , Vacinas/administração & dosagem , Vacinas/imunologia
15.
J Agric Food Chem ; 60(17): 4306-13, 2012 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-22494277

RESUMO

This study was designed to investigate the effects of long-term feeding of chitosan on postprandial lipid response and lipid metabolism in a high-sucrose (HS)-diet-impaired glucose-tolerant rat model. As the results, HS-diet-fed rats supplemented with 5 and 7% chitosan in diets for 9 weeks had lower postprandial plasma total cholesterol (TC) levels, but 7% chitosan in the diet had higher postprandial plasma triglyceride (TG) and TG-rich lipoprotein TG levels. Supplementation of chitosan significantly decreased the postprandial ratio of apolipoprotein B (apoB)48/apoB100 in TG-rich lipoprotein fractions of HS-diet-fed rats. Long-term supplementation of 5 and 7% chitosan in diets for 16 weeks had lower plasma TC, low-density lipoprotein cholesterol (LDL-C) + very low density lipoprotein cholesterol (VLDL-C), TC/high-density lipoprotein (HDL-C) ratio, leptin, and tumor necrosis factor-α (TNF-α) levels in HS-diet-fed rats. Moreover, it was noticed that the VLDL receptor (VLDLR) protein expression in skeletal muscles of HS-diet-fed rats was significantly decreased, which could be significantly reversed by supplementation of 5 and 7% chitosan. Rats supplemented with 7% chitosan in the diet significantly elevated the lipolysis rate and decreased the accumulation of TG in epididymal fat pads of HS-diet-fed rats. The plasma angiopoietin-like 4 (ANGPTL4) protein expression was not affected in HS-diet-fed rats, but it was significantly increased in 7% chitosan-supplemented HS-diet-fed rats. Taken together, these results indicate that supplementation of chitosan in the diet can improve the impairment of lipid metabolism in a HS-diet-fed rat model, but long-term high-dose chitosan feeding may enhance postprandial plasma TG and TG-rich lipoprotein TG levels in HS-diet-fed rats through an ANGPTL4-regulated pathway.


Assuntos
Quitosana/administração & dosagem , Sacarose Alimentar/administração & dosagem , Intolerância à Glucose/metabolismo , Metabolismo dos Lipídeos/efeitos dos fármacos , Lipídeos/sangue , Animais , Anticolesterolemiantes/administração & dosagem , Quitosana/efeitos adversos , Colesterol/sangue , Dieta , Suplementos Nutricionais , Intolerância à Glucose/induzido quimicamente , Hiperglicemia/induzido quimicamente , Hipertrigliceridemia/induzido quimicamente , Masculino , Período Pós-Prandial , Ratos , Ratos Sprague-Dawley , Triglicerídeos/sangue
16.
Int J Food Sci Nutr ; 63(5): 548-52, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22165994

RESUMO

Is well known that obesity has increased significantly in recent times and therefore many dietary supplements, synthetic or natural, have been proposed in order to prevent and/or to treat obesity or overweight. Chitosan, a polysaccharide with ability to act as a carrier and to absorb fat, has been used for this purpose. However, interactions with other molecules present in the body may also occur and, therefore, the purpose of this study was to evaluate interactions of chitosan with vitamin B12. Spectroscopic properties of vitamin B12 (acid aqueous solution) were monitored in the absence and the presence of chitosan in order to evaluate possible interactions between the two. Results showed that the rigid micro-environment generated by chitosan solution modifies the photophysical properties of vitamin B12. Thus, chitosan is able to eliminate vitamin B12 and, based on this information, some care must be taken during prolonged treatment with chitosan.


Assuntos
Fármacos Antiobesidade/efeitos adversos , Deficiência de Vitaminas/etiologia , Quitosana/efeitos adversos , Suplementos Nutricionais/efeitos adversos , Obesidade/metabolismo , Processos Fotoquímicos , Vitamina B 12/metabolismo , Fármacos Antiobesidade/química , Fármacos Antiobesidade/uso terapêutico , Deficiência de Vitaminas/metabolismo , Deficiência de Vitaminas/prevenção & controle , Quitosana/química , Quitosana/uso terapêutico , Obesidade/tratamento farmacológico , Vitamina B 12/química
17.
Vopr Pitan ; 80(4): 56-61, 2011.
Artigo em Russo | MEDLINE | ID: mdl-22232884

RESUMO

he effect of chitosan inclusion in the semi-synthetic diet of rats at a dose of 0,24 and 0,9% of dry weight on vitamin assimilation under combined moderate and deep deficiency has been studied. Four-week introduction of chitosan did not have a significant effect on levels of vitamins C, B1, B2 and A in the liver of animals, on vitamin B2 blood plasma concentration and thiamine and riboflavin urinary excretion regardless of the degree of vitamin deficiency intensity. The significantly decrease of vitamin E blood plasma concentration has been observed at high dose of chitosan in the diet under moderate vitamin deficiency, whereas under deep deficit such reduction has been detected even at a low dose. Thus, long-term chitosan inclusion in the diet under existing polyhypovitaminosis can lead to the deterioration of the sufficiency with fat-soluble vitamins.


Assuntos
Quitosana/efeitos adversos , Quitosana/farmacologia , Alimentos Formulados , Fígado/metabolismo , Vitaminas/sangue , Vitaminas/urina , Animais , Deficiência de Vitaminas , Masculino , Ratos , Ratos Wistar , Fatores de Tempo
19.
Immunopharmacol Immunotoxicol ; 31(2): 202-8, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19514994

RESUMO

Chitosan is capable of stimulating immune responses. However, because chitosan is not water soluble, it has limited biological applications. By attaching galactose molecules to the chitosan molecules, a new water-soluble compound, glycated chitosan (GC), was synthesized. GC was designed for immune stimulations in combination with phototherapies in the treatment of metastatic tumors. To investigate the possible toxicity of GC, cultures of normal and tumor cells were incubated with GC of different concentrations and the cell viabilities were determined. For in vivo studies, GC solution was fed or injected to animals and its toxicity was determined through observations of animals and histological examinations of vital organs. No toxic effects of GC were observed in cultured cells or in animal studies. In addition, the immunological effect of GC was investigated through its stimulation of TNFalpha secretion by macrophages in vitro. In vivo studies showed enhancement of the survival of laser immunotherapy-treated rats bearing metastatic mammary tumors. Our in vitro and in vivo results indicated that GC was a strong immunological stimulant. Its non-toxic nature and immunological activity make GC a potential immunoadjuvant for treatment of metastatic tumors.


Assuntos
Adjuvantes Imunológicos/farmacologia , Quitosana/farmacologia , Adjuvantes Imunológicos/efeitos adversos , Adjuvantes Imunológicos/química , Animais , Células Cultivadas , Quitosana/efeitos adversos , Quitosana/química , Feminino , Galactose/química , Verde de Indocianina/farmacologia , Terapia a Laser , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Neoplasias Mamárias Experimentais/terapia , Camundongos , Fototerapia , Ratos , Ratos Endogâmicos WF , Solubilidade , Fator de Necrose Tumoral alfa/metabolismo
20.
Altern Med Rev ; 12(3): 265-73, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18072822

RESUMO

UNLABELLED: Hypercholesterolemia is an important risk factor for cardiovascular disease (CVD). OBJECTIVE: To compare the efficacy of a 12-week treatment regimen with HEP-40 low-molecular weight chitosan given at daily doses of 1,200 mg, 1,600 mg, and 2,400 mg in reducing serum low-density lipoprotein cholesterol (LDL-C) in patients with low-to-moderate hypercholesterolemia. DESIGN: The study was a 16-week, multicenter, placebo-controlled, randomized study. Eligible patients were treatment-naive for lipid-lowering medications. Patients were randomly assigned to HEP-40 at the following doses: 400 mg three times daily, 800 mg twice daily, 800 mg three times daily, 2,400 mg once daily, or placebo for 12 weeks. The main outcome measure was the percent change in LDL-C after four weeks of treatment. RESULTS: Out of 283 patients screened, 105 (37.1%) fulfilled the inclusion criteria and 95 (90.4%) completed the study. The mean (SD) age was 53 (11) years and 62.3 percent were male. The majority of patients (82.9%) were at low 10-year risk for CVD. The results showed an overall treatment effect (p=0.040) with the highest difference from the placebo group observed for the HEP-40 2,400-mg once daily group (-16.9%, p=0.002), followed by 400 mg three times daily (-11.1%, p=0.054), 800 mg three times daily (-9.7%, p=0.065), and 800 mg twice daily (-8.7%, p=0.101). There were 29 predominantly mild adverse events reported by 24 (23%) patients related to the study treatment, most frequently constipation (3.0%) and diarrhea (3.0%). CONCLUSION: HEP-40 low-molecular weight chitosan, although not as effective as statins, is efficacious and safe in lowering LDL-C concentrations in treatment-naive patients with low-to-moderate hypercholesterolemia.


Assuntos
Anticolesterolemiantes/uso terapêutico , Quitosana/uso terapêutico , Hipercolesterolemia/tratamento farmacológico , Análise de Variância , Anticolesterolemiantes/efeitos adversos , Quitosana/efeitos adversos , LDL-Colesterol/sangue , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
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