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1.
Plant Physiol Biochem ; 205: 108195, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37995580

RESUMO

Iron and zinc deficiencies are the most prevalent cause of global hidden hunger. Rice, being one of the most consumed crops worldwide, is suitable to target for Fe and Zn biofortification. In present study, we generated rice transgenic lines to meet the recommended dietary requirement of iron and zinc through endosperm specific expression of dicot (kidney bean) and monocot (pearl millet) Ferritins along with constitutive expression of rice nicotianamine synthase 2 (OsNAS2) gene. Visualization through perls' prussian staining and quantification by ICP-MS showed significant improvement in grain iron content in all the transgenic lines. The transgenic lines expressing any of the three selected gene combinations (PvFerrtin-OsNAS2, feedPgFerrtin-OsNAS2 and foodPgFerritin-OsNAS2), showed the potential to surpass the 30% of the estimated average requirement (13 µg/g Fe and 28 µg/g Zn) proposed for rice in HarvestPlus breeding program. Though the expression of PvFerritin along with OsNAS2 gene in IET10364 (indica) variety showed the best result, providing up to 4.2- and 3.5-fold increase in iron (30.56 µg/g) and zinc (60.1 µg/g) content, respectively; in polished grains compared to non-transgenic control. Thus, the lines developed in our study can be used for further breeding purpose to enhance the iron and zinc content in commercial rice varieties.


Assuntos
Oryza , Pennisetum , Phaseolus , Ferro/metabolismo , Ferritinas/genética , Ferritinas/metabolismo , Zinco/metabolismo , Phaseolus/genética , Phaseolus/metabolismo , Pennisetum/genética , Pennisetum/metabolismo , Oryza/genética , Oryza/metabolismo , Biofortificação , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Melhoramento Vegetal
2.
Nat Prod Res ; : 1-6, 2023 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-37874669

RESUMO

Asparagus racemosus Linn. is an ethnopharmacologically important plant having extensive uses in Ayurveda, Unani, and Siddha. This study was carried out to evaluate the chemical profile of A. racemosus Linn. using GC-MS and FT-IR analysis, and its polyphenol content and antioxidant effects. Plants were collected from Bhujiyaghat, Nainital (29.3159° N, 79.5245° E) in Kumaun Himalayas. GC-MS with FT-IR analysis identified multiple functional groups, including carboxylic acid derivatives. Methyl 11, 12-octadecadienoate, was screened as the major compounds by GC-MS. A. racemosus contains a high concentration of phenols (80.92 ± 0.57 mg of GAE/g of DW), flavonoids (58.22 ± 1.62 mg of QE/g of DW), and tannins (86.77 ± 0.81 mg of TAE/g of DW). DPPH (24.63 ± 0.21 g/ml) and FRAP (72.49483 ± 0.130549 mg of AAE/g of DW) assays revealed the presence of significant antioxidant activity in A. racemosus.

3.
Curr Drug Deliv ; 19(2): 182-191, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34288837

RESUMO

Polyphenols comprise a large group of naturally occurring plant secondary metabolites with various nutritional and health benefits. They are safe and are found abundantly in the diet. Current research on polyphenols focuses on their mechanism and their benefits on human health. However, due to their low solubility and bioavailability, delivery from the conventional route has been a challenge and their translation into clinical applications has been limited. Topical and transdermal delivery of polymeric nanoparticles will act as a novel therapeutic approach for promising delivery of polyphenols. In this review, we have evaluated the existing scientific literature and summarized the potential use of polymeric nanoparticles as a carrier for polyphenolic compounds for delivery via topical and transdermal routes for the treatment of skin cancers such as melanoma.


Assuntos
Melanoma , Nanopartículas , Administração Cutânea , Sistemas de Liberação de Medicamentos , Humanos , Polímeros , Polifenóis
4.
Pharm Res ; 38(5): 851-871, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33982225

RESUMO

Polyphenols such as curcumin (Cur) and resveratrol (Res) have been recently shown to have potential to inhibit proliferation of highly aggressive melanoma cells. This study was designed to investigate the feasibility of a topical delivery system, using a solid lipid nanoparticles (SLNs) loaded delivery systems, that can enhance the skin penetration and anti-cancer efficacy of combination of these polyphenols. Negatively charged Cur-Res SLNs with a mean diameter of 180.2 ± 7.7 nm were prepared using high shear homogenization method. Cur-Res SLNs were found to be stable up to 2 weeks under 4°C. The in vitro release study showed that Res was released five time more than curcumin. The permeability of resveratrol was about 1.67 times that of curcumin from the SLN-gel formulation which was significantly (p < 0.05) lower than from SLN suspension. More than 70% of Cur-Res SLNs were bound to skin locally in a skin binding study suggesting potentially utility of Cur-Res SLNs in the treatment of localized melanoma. In fact, the electrical cell-substrate impedance sensing (ECIS) measurements suggested that Cur-Res combination has potential to stop cell migration of B16F10 melanoma cells. Furthermore, both, Cur-Res SLNs and Cur-Res solution at the ratio of 3:1 demonstrated a strong synergistic inhibition of SK-MEL-28 melanoma cell proliferation. Further evaluation of Cur-Res SLNs in vivo melanoma models are warranted to establish the clinical utility of Cur-Res formulations in melanoma therapy.


Assuntos
Curcumina/administração & dosagem , Portadores de Fármacos/química , Melanoma/tratamento farmacológico , Resveratrol/administração & dosagem , Neoplasias Cutâneas/tratamento farmacológico , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Curcumina/farmacocinética , Combinação de Medicamentos , Liberação Controlada de Fármacos , Humanos , Lipídeos/química , Melanoma/patologia , Camundongos , Nanopartículas , Tamanho da Partícula , Permeabilidade , Resveratrol/farmacocinética , Pele/metabolismo , Pele/patologia , Neoplasias Cutâneas/patologia , Serpentes
5.
Eur J Pharm Biopharm ; 161: 66-79, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33588032

RESUMO

The emergence of multi-drug resistant (MDR) pathogens has become a global threat and a cause of significant morbidity and mortality around the world. Natural products have been used as a promising approach to counter the infectious diseases associated with these pathogens. The application of natural products and their derivatives especially polyphenolic compounds as antibacterial agents is an active area of research, and prior studies have successfully treated a variety of bacterial infections using these polyphenolic compounds. However, delivery of polyphenolic compounds has been challenging due to their physicochemical properties and often poor aqueous solubility. In this regard, nanotechnology-based novel drug delivery systems offer many advantages, including improving bioavailability and the controlled release of polyphenolic compounds. This review summarizes the pharmacological mechanism and use of nano-formulations in developing controlled release delivery systems of naturally occurring polyphenols in infectious diseases.


Assuntos
Antibacterianos/administração & dosagem , Infecções Bacterianas/tratamento farmacológico , Polifenóis/administração & dosagem , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Infecções Bacterianas/microbiologia , Disponibilidade Biológica , Produtos Biológicos/administração & dosagem , Produtos Biológicos/química , Produtos Biológicos/farmacologia , Preparações de Ação Retardada , Sistemas de Liberação de Medicamentos , Farmacorresistência Bacteriana Múltipla , Humanos , Nanopartículas , Nanotecnologia , Polifenóis/química , Polifenóis/farmacologia , Solubilidade
6.
AAPS PharmSciTech ; 22(1): 30, 2021 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-33404926

RESUMO

Intranasal (IN) administration is known to be noninvasive with the potential to carry a drug or vaccine directly to the blood, bypassing first-pass metabolism in the liver and the harsh environment of the gastrointestinal system. Orally administered dibenzoylmethane (DBM) has been shown experimentally to be neuroprotective in animal models of tauopathy and prion disease and effective in the treatment of certain forms of cancers. The purpose of this study was to prepare, characterize, and test formulations of DBM designed for IN administration. DBM was formulated in brain homogenate (BH) and hypromellose and as nanoparticles (NPs). These formulations were detected using UPLC and characterized in solid and suspension states; NPs were also characterized by in vitro cell culture-based studies. Particle size for DBM NP was 163.8 ± 3.2 nm, and in vitro release studies showed 95.80% of DBM was released from the NPs within 8 days. In vitro cell, culture studies suggested no drug uptake until 6 h. A histological analysis of nasal cavity (NC) sections and blood detection studies were carried out 30 min after inhalation. DBM amounting to 40.77 ± 4.93 and 44.45 ± 5.36 ng/mL was detected in the blood of animals administered DBM in polymeric and NP formulation, respectively. Histological studies on NCs confirmed the presence of BH within lymphatic vessels in the lamina propria of each animal; BH was identified traversing the mucosa in 2 animals. Thus, formulations for DBM administered via IN route were successfully designed and characterized and able to cross the nasal mucosa following inhalation.


Assuntos
Chalconas/administração & dosagem , Mucosa Nasal/efeitos dos fármacos , Administração Intranasal , Animais , Encéfalo/metabolismo , Portadores de Fármacos/administração & dosagem , Sistemas de Liberação de Medicamentos , Nanopartículas/administração & dosagem , Mucosa Nasal/metabolismo , Tamanho da Partícula
7.
AAPS PharmSciTech ; 20(6): 250, 2019 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-31297635

RESUMO

Melanoma is regarded as the fifth and sixth most common cancer in men and women, respectively, and it is estimated that one person dies from melanoma every hour in the USA. Unfortunately, the treatment of melanoma is difficult because of its aggressive metastasis and resistance to treatment. The treatment of melanoma continues to be a challenging issue due to the limitations of available treatments such as a low response rate, severe adverse reactions, and significant toxicity. Natural polyphenols have attracted considerable attention from the scientific community due to their chemopreventive and chemotherapeutic efficacy. It has been suggested that poorly soluble polyphenols such as curcumin, resveratrol, quercetin, coumarin, and epigallocatechin-3-gallate may have significant benefits in the treatment of melanoma due to their antioxidant, anti-inflammatory, antiproliferative, and chemoprotective efficacies. The major obstacles for the use of polyphenolic compounds are low stability and poor bioavailability. Numerous nanoformulations, including solid lipid nanoparticles, polymeric nanoparticles, micelles, and liposomes, have been formulated to enhance the bioavailability and stability, as well as the therapeutic efficacy of polyphenols. This review will provide an overview of poorly soluble polyphenols that have been reported to have antimetastatic efficacy in melanomas.


Assuntos
Sistemas de Liberação de Medicamentos/métodos , Melanoma/tratamento farmacológico , Polifenóis/administração & dosagem , Polifenóis/química , Neoplasias Cutâneas/tratamento farmacológico , Animais , Antioxidantes/administração & dosagem , Antioxidantes/química , Antioxidantes/metabolismo , Disponibilidade Biológica , Catequina/administração & dosagem , Catequina/análogos & derivados , Catequina/química , Catequina/metabolismo , Curcumina/administração & dosagem , Curcumina/química , Curcumina/metabolismo , Humanos , Melanoma/metabolismo , Melanoma/prevenção & controle , Nanopartículas/administração & dosagem , Nanopartículas/química , Nanopartículas/metabolismo , Polifenóis/metabolismo , Quercetina/administração & dosagem , Quercetina/química , Quercetina/metabolismo , Resveratrol/administração & dosagem , Resveratrol/química , Resveratrol/metabolismo , Neoplasias Cutâneas/metabolismo , Solubilidade
8.
Drug Dev Ind Pharm ; 45(8): 1277-1291, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31111732

RESUMO

The major goal of this research was to successfully formulate solid dispersion (SD) of the poorly soluble anticancer drug flutamide (FLT) using various hydrophilic polymers. Furthermore, to get more insight into SD, solid-state studies (miscibility and molecular interaction) were correlated with solution study (precipitation inhibition, dissolution). Hydrophilic polymers like PVP K90, HPMC, Eudragit EPO, and PEG 8000 were used at different drug-to-polymer w/w ratios. Solid-state miscibility studies were carried out using modulated differential scanning calorimetry (MDSC). SDs were prepared using solvent-evaporation technique and characterized by powder X-ray diffraction (PXRD) and MDSC. Infrared, Raman spectroscopy and molecular modeling were used to investigate drug-polymer interactions in the dispersions. Precipitation inhibition studies were carried out at various FLT-hydrophilic polymer ratios. Precipitation inhibition studies showed that PEG 8000 has the highest efficiency, followed by PVP K90, while HPMC and EPO showed no effect on precipitation inhibition. In the solid-state, MDSC of the physical mixture (PM) suggested that FLT is miscible to a greater extent with EPO and PEG 8000. Characterization of the amorphous dispersions using MDSC and PXRD concluded that FLT transformed from crystalline to amorphous form in the presence of PVP K90 and PEG 8000. Spectroscopic results confirmed stronger interaction of FLT with PVP K90 and PEG 8000, thereby confirming the in-solution precipitation and molecular modeling binding energy results. Amorphous dispersions formulated with PVP and PEG were stable and showed higher dissolution, an important property necessary to improve the physicochemical properties and drug delivery of poorly soluble anticancer drug FLT.


Assuntos
Antineoplásicos/química , Flutamida/química , Polímeros/química , Varredura Diferencial de Calorimetria/métodos , Cristalização/métodos , Portadores de Fármacos/química , Composição de Medicamentos/métodos , Polietilenoglicóis/química , Ácidos Polimetacrílicos/química , Pós/química , Solubilidade/efeitos dos fármacos , Difração de Raios X/métodos
9.
AAPS PharmSciTech ; 20(5): 163, 2019 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-30993475

RESUMO

Cataract, one of the leading causes of blindness worldwide, is a condition in which complete or partial opacity develops in the lens of the eyes, thereby impairing vision. This study aimed to examine the potential therapeutic and protective effects of poorly soluble polyphenols like curcumin, resveratrol, and dibenzoylmethane, known to possess significant antioxidant activity. The polyphenols were loaded into novel lipid-cyclodextrin-based nanoparticles and characterized by particle size, polydispersity index, differential scanning calorimetry, thermogravimetric analysis, X-ray diffraction, scanning electron microscopy (SEM), entrapment efficiency, and release studies. Ferric-reducing ability of plasma and 2,2-diphenyl-1-picrylhydrazyl chemical assays were used to evaluate their antioxidant properties based on their free radical quenching ability. Biochemical in vitro assays were used to examine these polyphenols on hydrogen peroxide-induced formation of cataracts in bovine lenses by estimating total glutathione content and superoxide dismutase activity. Nanoparticles were thermostable and amorphous. Particle size of curcumin, resveratrol, and dibenzoylmethane nanoparticles were 331.0 ± 17.9 nm, 329.9 ± 1.9 nm, and 163.8 ± 3.2 nm, respectively. SEM confirmed porous morphology and XRD confirmed physical stability. Entrapment efficiency for curcumin-, resveratrol-, and dibenzoylmethane-loaded nanoparticles was calculated to be 84.4 ± 2.4%, 72.2 ± 1.5%, and 86.4 ± 0.6%, respectively. In vitro release studies showed an initial burst release followed by a continuous release of polyphenols from nanoparticles. Chemical assays confirmed the polyphenols' antioxidant activity. Superoxide dismutase and glutathione levels were found to be significantly increased (p < 0.05) after treatment with polyphenol-loaded nanoparticles than pure polyphenols; thus, an improved antioxidant activity translational into potential anticataract activity of the polyphenols when loaded into nanoparticles was observed as compared to pure polyphenols.


Assuntos
Antioxidantes/uso terapêutico , Catarata/tratamento farmacológico , Nanopartículas/química , Polifenóis/química , Animais , Antioxidantes/administração & dosagem , Antioxidantes/química , Bovinos , Composição de Medicamentos , Estabilidade de Medicamentos , Técnicas In Vitro , Tamanho da Partícula , Solubilidade
10.
AAPS PharmSciTech ; 20(4): 145, 2019 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-30887133

RESUMO

Curcumin and resveratrol are natural compounds with significant anticancer activity; however, their bioavailability is limited due to poor solubility. This study aimed to overcome the solubility problem by means of solid lipid nanoparticles (SLN). 2-Hydroxypropyl ß-cyclodextrin (HPßCD) was selected from a range of polymers based on miscibility and molecular interactions. SLNs were obtained by probe sonication and freeze-drying curcumin-resveratrol with/without HPßCD incorporated in gelucire 50/13. SLNs were characterized by dynamic light scattering (DLS), zeta potential, powder X-ray diffractometry (PXRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and physical stability. The in vitro release of drugs from the SLNs was performed by the direct dispersion method and analyzed using a validated UV-visible method. In vitro efficacy was tested using a colorectal cancer cell line. Curcumin-resveratrol-gelucire 50/13-HPßCD (CRG-CD) and curcumin-resveratrol-gelucire 50/13(CRG) SLNs showed a particle size from 100 to 150 nm and were not in the crystalline state per PXRD results. MDSC results complimented PXRD results by the absence of melting endotherm of curcumin; TGA showed no weight loss, confirming the absence of organic solvent residual, and the shape of the SLNs was confirmed as spherical by SEM. CRG SLNs were stable for 21 days with respect to particle size and zeta potential. MTT assay indicated better IC50 value for CRG as compared to CRG-CD. Hence, novel SLNs of curcumin and resveratrol incorporated in gelucire 50/13 and HPßCD were prepared and characterized to improve their bioavailability and anticancer activity.


Assuntos
Curcumina/química , Curcumina/farmacologia , Lipídeos/química , Nanopartículas/química , Resveratrol/química , Resveratrol/farmacologia , Disponibilidade Biológica , Varredura Diferencial de Calorimetria , Portadores de Fármacos , Humanos , Técnicas In Vitro , Microscopia Eletrônica de Varredura , Tamanho da Partícula , Polímeros , Solubilidade
11.
J Ethnopharmacol ; 213: 302-310, 2018 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-29113957

RESUMO

ETHNOBOTANICAL RELEVANCE: Trillium govanianum Wall. ex D. Don (Melanthiaceae) is valued as a traditional medicinal herb in the Himalayan region. Applications include treatment of cancer, hypertension, neurasthenia, giddiness, arthritis, dysentery, inflammation, sepsis and reproductive disorders. Its range is highly specific, and limited to cold, shaded and moist habitats at 2400-3500 m a.s.l. Rhizomes are gathered from wild populations for trade, and this has recently emerged as a significant source of income among indigenous people of the Indian Himalayan region. AIM: To assess the impact of changing rhizome prices on T. govanianum in the Indian Himalayan region by observing the status of existing populations and assessing the typical methods used for gathering and trade of rhizomes. MATERIAL AND METHODS: Ecological attributes were assessed in 17 sites from Tirthan Valley (Himachal Pradesh), Munsiyari and Tunghnath (Uttarakhand). Socio-economic attributes assessed through communal focus groups and interviews with 579 medicinal plants gatherers and 19 traders, using semi-structured open ended questionnaires. RESULTS: Population decline was highest in Munsiyari, followed by Tirthan Valley and Tunghnath, indicating that the species may become locally extinct in some areas. Methods used for gathering did not consider regeneration. CONCLUSION: Gathering of T. govanianum from wild populations is unselective and unmanaged, raising the potential threat of local extinctions. Sustainable utilization and effective conservation is needed to protect the species and maintain community incomes. A status of 'threatened' is justified for the species in the Indian Himalayan region, due to its slow life cycle, specific habitat requirement, low population density, and commercial value.


Assuntos
Agricultura/métodos , Conservação dos Recursos Naturais/tendências , Trillium , Humanos , Plantas Medicinais , Fatores Socioeconômicos
12.
Nutr Cancer ; 68(6): 879-91, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27366999

RESUMO

Resistance to chemotherapy remains a major impediment to the management of most types of cancer. Both intrinsic and acquired drug resistance are mediated by several cellular and molecular mechanisms, including alternative growth-signaling pathways unaffected by specific therapies, alterations in the tumor microenvironment (e.g., hypoxia and angiogenesis), and active transport of drugs out of the cell. Epidemiological studies have validated an inverse correlation between the consumption of dietary polyphenols and the risk of cancer, which has been attributed to polyphenol antioxidant capacity and their potential to inhibit activation of procarcinogens, cancer cell proliferation, metastasis, and angiogenesis, and inhibition or downregulation of active drug efflux transporters. Moreover, polyphenols can induce apoptosis in cancer cells and modulate immune responses and inflammatory cascades. Augmentation of the efficacy of chemotherapy and prevention of multidrug resistance are other important effects of dietary polyphenols that deserve further research, especially after the discovery of tight "crosstalk" between aberrant growth signaling and metabolic dysfunction in cancer cells. In this review, we cover what is currently known about the role of natural polyphenolic compounds in overcoming cancer drug resistance mediated by diverse primary and secondary resistance mechanisms.


Assuntos
Antineoplásicos Fitogênicos/uso terapêutico , Resistencia a Medicamentos Antineoplásicos , Flavonoides/uso terapêutico , Modelos Biológicos , Neoplasias/dietoterapia , Neoplasias/tratamento farmacológico , Polifenóis/uso terapêutico , Animais , Antineoplásicos/metabolismo , Antineoplásicos/uso terapêutico , Derivados de Benzeno/uso terapêutico , Transporte Biológico , Terapia Combinada , Suplementos Nutricionais , Resistência a Múltiplos Medicamentos , Humanos , Proteínas de Neoplasias/antagonistas & inibidores , Proteínas de Neoplasias/metabolismo , Neoplasias/metabolismo
13.
Mol Pharm ; 13(3): 756-65, 2016 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-26866895

RESUMO

We are reporting a synergistic effect of combined Eudragit E100 and PVP K90 in precipitation inhibition of indomethacin (IND) in solutions at low polymer concentration, a phenomenon that has significant implications on the usefulness of developing novel ternary solid dispersion of poorly soluble drugs. The IND supersaturation was created by cosolvent technique, and the precipitation studies were performed in the absence and the presence of individual and combined PVP K90 and Eudragit E100. The studies were also done with PEG 8000 as a noninteracting control polymer. A continuous UV recording of the IND absorption was used to observe changes in the drug concentration over time. The polymorphic form and morphology of precipitated IND were characterized by Raman spectroscopy and scanning electron microscopy. The change in the chemical shift in solution (1)H NMR was used as novel approach to probe IND-polymer interactions. Molecular modeling was used for calculating binding energy between IND-polymer as another indication of IND-polymer interaction. Spontaneous IND precipitation was observed in the absence of polymers. Eudragit E100 showed significant inhibitory effect on nuclei formation due to stronger interaction as reflected in higher binding energy and greater change in chemical shift by NMR. PVP K90 led to significant crystal growth inhibition due to adsorption on growing IND crystals as confirmed by modified crystal habit of precipitate in the presence of PVP K90. Combination of polymers resulted in a synergistic precipitation inhibition and extended supersaturation. The NMR confirmed interaction between IND-Eudragit E100 and IND-PVP K90 in solution. The combination of polymers showed similar peak shift albeit using lower polymer concentration indicating stronger interactions. The results established the significant synergistic precipitation inhibition effect upon combining Eudragit E100 and PVP K90 due to drug-polymer interaction.


Assuntos
Acrilatos/química , Precipitação Química , Indometacina/química , Polímeros/química , Polivinil/química , Povidona/química , Pirrolidinas/química , Tecnologia Farmacêutica/métodos , Cristalização , Estabilidade de Medicamentos , Polietilenoglicóis , Solubilidade , Análise Espectral Raman
14.
J Pharm Sci ; 103(11): 3511-3523, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25196860

RESUMO

The purpose of this study was to understand the combined effect of two polymers showing drug-polymer interactions on amorphous stabilization and dissolution enhancement of indomethacin (IND) in amorphous ternary solid dispersions. The mechanism responsible for the enhanced stability and dissolution of IND in amorphous ternary systems was studied by exploring the miscibility and intermolecular interactions between IND and polymers through thermal and spectroscopic analysis. Eudragit E100 and PVP K90 at low concentrations (2.5%-40%, w/w) were used to prepare amorphous binary and ternary solid dispersions by solvent evaporation. Stability results showed that amorphous ternary solid dispersions have better stability compared with amorphous binary solid dispersions. The dissolution of IND from the ternary dispersion was substantially higher than the binary dispersions as well as amorphous drug. Melting point depression of physical mixtures reveals that the drug was miscible in both the polymers; however, greater miscibility was observed in ternary physical mixtures. The IR analysis confirmed intermolecular interactions between IND and individual polymers. These interactions were found to be intact in ternary systems. These results suggest that the combination of two polymers showing drug-polymer interaction offers synergistic enhancement in amorphous stability and dissolution in ternary solid dispersions.


Assuntos
Acrilatos/química , Portadores de Fármacos , Indometacina/química , Polímeros/química , Povidona/química , Química Farmacêutica , Estabilidade de Medicamentos , Cinética , Modelos Químicos , Solubilidade , Espectrofotometria Infravermelho , Análise Espectral Raman , Tecnologia Farmacêutica/métodos , Temperatura de Transição
15.
Transgenic Res ; 20(2): 231-46, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20549349

RESUMO

Osmotin and osmotin-like proteins are stress proteins belonging to the plant PR-5 group of proteins induced in several plant species in response to various types of biotic and abiotic stresses. We report here the overexpression of tobacco osmotin in transgenic mulberry plants under the control of a constitutive promoter (CaMV 35S) as well as a stress-inducible rd29A promoter. Southern analysis of the transgenic plants revealed the stable integration of the introduced genes in the transformants. Real-time PCR analysis provided evidence for the expression of osmotin in the transgenic plants under both the constitutive and stress-inducible promoters. Transgenic plants with the stress-inducible promoter were observed to better tolerate salt and drought stress than those with the constitutive promoter. Transgenic plants when subjected to simulated salinity and drought stress conditions showed better cellular membrane stability (CMS) and photosynthetic yield than non-transgenic plants under conditions of both salinity and drought stress. Proline levels were very high in transgenic plants with the constitutive promoter relative to those with the stress-inducible promoter. Fungal challenge undertaken with three fungal species known to cause serious losses to mulberry cultivation, namely, Fusarium pallidoroseum, Colletotrichum gloeosporioides and Colletotrichum dematium, revealed that transgenic plants with osmotin under control of the constitutive promoter had a better resistance than those with osmotin under the control of the stress-inducible promoter. Evaluation in next generation was undertaken by studying bud break in transgenic and non-transgenic plants under simulated drought (2% polyethylene glycol) and salt stress (200 mM NaCl) conditions. The axillary buds of the selected transgenic lines had a better bud break percentage under stressed conditions than buds from non-transgenic mulberry lines. A biotic assay with Bombyx mori indicated that osmotin protein had no undesirable effect on silkworm rearing and feeding. We therefore conclude that 35S transgenic plants are better suited for both abiotic stress also biotic challenges (fungal), while the rd29A transgenic plants are more responsive to drought.


Assuntos
Resposta ao Choque Térmico , Morus/metabolismo , Nicotiana/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Transformação Genética , Animais , Bombyx/fisiologia , Clonagem Molecular , Secas , Fungos/fisiologia , Regulação da Expressão Gênica de Plantas , Resposta ao Choque Térmico/genética , Resposta ao Choque Térmico/fisiologia , Morus/genética , Morus/microbiologia , Fotossíntese , Folhas de Planta/fisiologia , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/genética , Reação em Cadeia da Polimerase , Rhizobium/genética , Cloreto de Sódio/farmacologia , Esporos Fúngicos/fisiologia
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