Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 7 de 7
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Bioorg Med Chem Lett ; 80: 129118, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36581301

RESUMO

Human skeleton requires an adequate supply of many different nutritional factors for optimal growth and development. The role of nutrition in bone growth has piqued interest in recent years, especially in relation to maximizing peak bone mass and reducing the risk of osteoporosis. Protein deficiency-induced bone loss was induced in female growing rats. All experimental rodent diets were prepared as per recommendations for growing animals. 9-Demethoxy-medicarpin (DMM) treatment was given to growing Sprague Dawley (SD) rats at 1 mg and 10 mg dose orally for 30 days. Bones were collected for bone mineral density (BMD). Bone marrow cells were isolated from femur for calcium nodule formation. Serum samples were collected for biochemical parameters. We found that DMM treatment speeds up the recovery of musculoskeletal weakness by replenishing nutrients in proven rodent model. DMM supplementation for four weeks showed significantly increased vertebral, femur and tibial BMD compared with the untreated PD group. Albumin levels were significantly enhanced in treatment groups, in which 10 mg dose imparted a better effect. We conclude that DMM treatment led to increased BMD and biochemical parameters in protein deficient condition in growing rats and has potential as a bone growth supplement.


Assuntos
Densidade Óssea , Osso e Ossos , Animais , Feminino , Humanos , Ratos , Suplementos Nutricionais , Ratos Sprague-Dawley
2.
Phytomedicine ; 93: 153750, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34662767

RESUMO

BACKGROUND: Osteoporosis is an asymptomatic bone disorder leading to altered bone microarchitecture, mineralization and strength. Musa paradisiaca has been reported to have antioxidant and anti-inflammatory effects in various diseases. Its impact on postmenopausal osteoporosis has not been investigated yet. PURPOSE: The intention of the current study was to evaluate the bone regeneration and osteoprotective potential of extract and fraction of M. paradisiaca flower in ovariectomized (Ovx) Sprague Dawley (SD) rats, a model of post-menopausal bone loss. The study also aims to identify osteogenic compounds from active fraction. METHODS: Ethanolic extract (MFE) and butanolic fraction (MFE-Bu) from flower of M. paradisiaca were prepared and their efficacy was tested in rat femur osteotomy model at different doses. Effective dose from both extract (250 mg/kg) and fraction (50 mg/kg) were taken for study in osteopenic bone loss model. PTH was taken as reference standard (20 µg/kg/twice a week). Bones were harvested at autopsy for dynamic and static histomorphometry. Serum was collected for ELISA. Pure compounds were isolated from butanolic fraction (MFE-Bu), and were assessed for their osteogenic effect. RESULTS: MFE and MFE-Bu were observed for their potential in bone healing and prevention of bone loss. Both MFE and MFE-Bu promoted new bone regeneration at injury site as assessed by microCT and calcein dye labeling studies. These also led to restoration of bone microarchitecture deteriorated as a result of osteopenia and improved bone biomechanical properties. Extract as well as the fraction exhibited dual bone anabolic and anti-resorptive properties where they elevated serum procollagen type I N-terminal propeptide (P1NP), a bone formation marker and suppressed serum C-telopeptide of type I collagen (CTX-1), a bone resorption marker. As many as four osteogenic compounds were isolated from MFE-Bu. Oleracein-E was found to be the most potent osteogenic agent based on osteoblast differentiation, mineralization assays, qPCR and protein expression studies. CONCLUSION: Our studies demonstrates that ethanolic extract from the flower of M. paradisiaca and its butanolic fraction exhibit dual osteogenic and anti-resorptive potential, and have an advantage over PTH which though promotes bone formation but is also bone catabolic in nature.


Assuntos
Doenças Ósseas Metabólicas , Musa , Animais , Densidade Óssea , Flores , Humanos , Osteogênese , Ovariectomia , Extratos Vegetais/farmacologia , Ratos , Ratos Sprague-Dawley
3.
Sci Rep ; 11(1): 7003, 2021 03 26.
Artigo em Inglês | MEDLINE | ID: mdl-33772066

RESUMO

Octanoic acid is a medium-chained saturated fatty acid found abundantly in the ketogenic dietary supplements containing medium chained triglycerides (MCT) along with decanoic acid. The MCT ketogenic diet is commonly consumed for weight loss but has also showcased neuroprotective potential against neurodegenerative disorders. However, recent clinical findings have reported a critical disadvantage with the long-term consumption of ketogenic diet i.e. bone loss. The following study was employed to investigate whether the two major components of MCT diet also possess bone loss potential as observed with classical ketogenic diet. Swiss albino mice aged between 10 and 12 weeks, were divided into 3 treatment groups that were administered with oral suspensions of octanoic acid, decanoic acid and a combination of both for 4 weeks. Bone specific markers, microarchitectural parameters, using micro computed tomography, and biomechanical strength were analyzed. Remarkably deleterious alterations in the trabecular bone microarchitecture, and on bone markers were observed in the octanoic acid treated groups. Our results suggest significant negative effects on bone health by octanoic acid. These findings require further investigation and validation in order to provide significant clinically relevant data to possibly modify dietary composition of the MCT ketogenic diet.


Assuntos
Reabsorção Óssea/induzido quimicamente , Osso Esponjoso/fisiopatologia , Caprilatos/efeitos adversos , Ácidos Decanoicos/farmacologia , Dieta Cetogênica/efeitos adversos , Suplementos Nutricionais/efeitos adversos , Animais , Fenômenos Biomecânicos/efeitos dos fármacos , Densidade Óssea/efeitos dos fármacos , Dieta Rica em Proteínas e Pobre em Carboidratos/efeitos adversos , Fêmur/fisiopatologia , Corpos Cetônicos/urina , Masculino , Camundongos , Fármacos Neuroprotetores/efeitos adversos , Osteoclastos/efeitos dos fármacos , Distribuição Aleatória , Tíbia/fisiopatologia , Triglicerídeos/administração & dosagem
4.
Biomaterials ; 32(27): 6425-34, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21652067

RESUMO

Mesenchymal stem cells (MSCs) are being recognized as a viable cell source for cartilage repair and members of the transforming growth factor-beta (TGF-ß) superfamily are a key mediator of MSC chondrogenesis. While TGF-ß mediated MSC chondrogenesis is well established in in vitro pellet or hydrogel cultures, clinical translation will require effective delivery of TGF-ßs in vivo. Here, we investigated the co-encapsulation of TGF-ß3 containing alginate microspheres with human MSCs in hyaluronic acid (HA) hydrogels towards the development of implantable constructs for cartilage repair. TGF-ß3 encapsulated in alginate microspheres with nanofilm coatings showed significantly reduced initial burst release compared to uncoated microspheres, with release times extending up to 6 days. HA hydrogel constructs seeded with MSCs and TGF-ß3 containing microspheres developed comparable mechanical properties and cartilage matrix content compared to constructs supplemented with TGF-ß3 continuously in culture media, whereas constructs with TGF-ß3 directly encapsulated in the gels without microspheres had inferior properties. When implanted subcutaneously in nude mice, constructs containing TGF-ß3 microspheres resulted in superior cartilage matrix formation when compared to groups without TGF-ß3 or with TGF-ß3 added directly to the gel. However, calcification was observed in implanted constructs after 8 weeks of subcutaneous implantation. To prevent this, the co-delivery of parathyroid hormone-related protein (PTHrP) with TGF-ß3 in alginate microspheres was pursued, resulting in partially reduced calcification. This study demonstrates that the controlled local delivery of TGF-ß3 is essential to neocartilage formation by MSCs and that further optimization is needed to avert the differentiation of chondrogenically induced MSCs towards a hypertrophic phenotype.


Assuntos
Alginatos/química , Condrogênese/efeitos dos fármacos , Ácido Hialurônico/química , Hidrogéis/química , Células-Tronco Mesenquimais/citologia , Microesferas , Fator de Crescimento Transformador beta3/farmacologia , Animais , Cartilagem/efeitos dos fármacos , Cartilagem/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Módulo de Elasticidade/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Ácido Glucurônico/química , Ácidos Hexurônicos/química , Humanos , Imuno-Histoquímica , Implantes Experimentais , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/metabolismo , Camundongos , Proteína Relacionada ao Hormônio Paratireóideo/farmacologia
5.
Chem Biol ; 18(1): 121-30, 2011 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-21276945

RESUMO

Posttranslational arginylation mediated by arginyl transferase (ATE1) plays an important role in cardiovascular development, cell motility, and regulation of cytoskeleton and metabolic enzymes. This protein modification was discovered decades ago, however, the arginylation reaction and the functioning of ATE1 remained poorly understood because of the lack of good biochemical models. Here, we report the development of an in vitro arginylation system, in which ATE1 function and molecular requirements can be tested using purified recombinant ATE1 isoforms supplemented with a controlled number of components. Our results show that arginylation reaction is a self-sufficient, ATP-independent process that can affect different sites in a polypeptide and that arginyl transferases form different molecular complexes in vivo, associate with components of the translation machinery, and have distinct, partially overlapping subsets of substrates, suggesting that these enzymes play different physiological functions.


Assuntos
Aminoaciltransferases/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Arginina-tRNA Ligase/metabolismo , Bovinos , Extratos Celulares , Coenzimas/metabolismo , Isoenzimas/metabolismo , Camundongos , Ligação Proteica , Processamento de Proteína Pós-Traducional , Proteínas/química , Proteínas/metabolismo , Especificidade por Substrato
7.
Artigo em Inglês | MEDLINE | ID: mdl-17456910

RESUMO

The deleterious effect of ultraviolet radiation on humans has increased the need for photoprotection. Sunscreens are widely used as photo protective agents. They are divided into chemical sunscreens which absorb high-energy ultraviolet rays and physical blockers which reflect or scatter light. Effectiveness of sunscreens depends upon sun protection factor and its substantivity. Clothing is also important for sun protection and its effectiveness is measured by Ultraviolet Protection Factor. There are many other agents with photo protective properties, which range from antioxidants to plant extracts to DNA repair enzymes. Usage of wide brimmed hats and sunglasses, avoidance of solar exposure at times of peak intensity, use of cover-up garments and sunscreen lotions are effective for photo protection of the skin.


Assuntos
Roupa de Proteção , Queimadura Solar/prevenção & controle , Protetores Solares/uso terapêutico , Óculos , Humanos , Protetores Solares/efeitos adversos , Protetores Solares/química , Raios Ultravioleta
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA