RESUMO
Despite numerous beneficial therapeutic effects namely antioxidant and anti-inflammatory activity, Vitamin E has limited clinical applications due to its low water solubility. Throughout the present work, α-tocopherol's new PEGylated derivatives alongside with polyethylene glycol 300 (α-1TPGT300), 400 (α-TPGT400), and 1000 (α-TPGT1000) were synthesized. A 1,2,3-triazole ring was utilized as a linker for the attachment of alpha tocopherol to the PEGs through a click reaction. The purified derivatives were characterized by the means of 1H NMR, 13C NMR, mass spectroscopy, UV-vis and FT-IR methods. Synthesized derivatives' capacity to produce self-assembly nanoparticles was evaluated employing the critical micelle concentration (CMC) values. The stability of the micelles was studied by size analysis. In vitro cytotoxicity of the products was investigated using MTT assay against MCF-7 breast cancer cells. The IC50 value for TPGT1000 after 24 h treatment was 15.0 ± 1.8 µM, whereas no significant cytotoxicity effect was observed following the treatment of MCF-7 cells by TPGT300, 400. The present study showed that polymeric micelle TPGT1000 possessed better physicochemical and biological properties including relatively lower CMC value, higher stability in FBS environment in addition to higher cytotoxicity against MCF-7 breast cancer cells compared to the lower molecular weight PEGylated derivatives. These results confirmed that increasing PEG chain length left a positive effect on the polymeric micelle properties and also improved the cytotoxicity effect of new PEGylated vitamin E derivatives.
Assuntos
Nanocápsulas/química , Polietilenoglicóis/química , alfa-Tocoferol/síntese química , Sobrevivência Celular/efeitos dos fármacos , Química Click , Composição de Medicamentos , Humanos , Células MCF-7 , Micelas , Nanocápsulas/efeitos adversos , Tamanho da Partícula , Solubilidade , Triazóis/química , Vitamina E/químicaRESUMO
BACKGROUND: Vitamin E (α-tocopherol; α-T) deficiency causes spinocerebellar ataxia. α-T supplementation improves neurological symptoms, but little is known about the differential bioactivities of natural versus synthetic α-T during early life. OBJECTIVE: We assessed the effects of dietary α-T dose and source on tissue α-T accumulation and gene expression in adolescent α-tocopherol transfer protein-null (Ttpa-/-) mice. METHODS: Three-week-old male Ttpa-/- mice (n = 7/group) were fed 1 of 4 AIN-93G-based diets for 4 wk: vitamin E deficient (VED; below α-T limit of detection); natural α-T, 600 mg/kg diet (NAT); synthetic α-T, 816 mg/kg diet (SYN); or high synthetic α-T, 1200 mg/kg diet (HSYN). Male Ttpa+/+ littermates fed AIN-93G [75 mg synthetic α-T (CON)] served as controls (n = 7). At 7 wk of age, tissue α-T concentrations and stereoisomer profiles were measured for all groups. RNA-sequencing was performed on cerebella of Ttpa-/- groups. RESULTS: Ttpa-/- mice fed VED had undetectable brain α-T concentrations. Cerebral cortex α-T concentrations were greater in Ttpa-/- mice fed NAT (9.1 ± 0.7 nmol/g), SYN (10.8 ± 1.0 nmol/g), and HSYN (13.9 ± 1.6 nmol/g) compared with the VED group but were significantly lower than in Ttpa+/+ mice fed CON (24.6 ± 1.2 nmol/g) (P < 0.001). RRR-α-T was the predominant stereoisomer in brains of Ttpa+/+ mice (â¼40%) and Ttpa-/- mice fed NAT (â¼94%). α-T stereoisomer composition was similar in brains of Ttpa-/- mice fed SYN and HSYN (2R: â¼53%; 2S: â¼47%). Very few of the 16,774 genes measured were differentially expressed. However, compared with the NAT diet, HSYN significantly downregulated 20 myelin genes, including 2 transcription factors: SRY-box transcription factor 10 (Sox10) and myelin regulatory factor (Myrf), and several downstream target genes (false discovery rate <0.05). CONCLUSIONS: High-dose synthetic α-T compared with natural α-T alters myelin gene expression in the adolescent mouse cerebellum, which could lead to morphological and functional abnormalities later in life.
Assuntos
Proteínas de Transporte/metabolismo , Cerebelo/metabolismo , Bainha de Mielina/metabolismo , alfa-Tocoferol/síntese química , alfa-Tocoferol/farmacologia , Ração Animal/análise , Animais , Peso Corporal , Proteínas de Transporte/genética , Cerebelo/efeitos dos fármacos , Dieta , Ingestão de Alimentos , Regulação da Expressão Gênica/efeitos dos fármacos , Masculino , Camundongos , Camundongos KnockoutRESUMO
Natural antioxidants and vitamins have potential to protect biological systems from peroxidative damage induced by peroxyl radicals, α-tocopherol (Vitamin E, lipid soluble) and ascorbic acid (vitamin C, water soluble), well known natural antioxidant molecules. In the present study we described the synthesis and biological evaluation of hybrid of these two natural antioxidants with each other via ammonium di-ethylether linker, Toc-As in gene delivery. Two control cationic lipids N14-As and Toc-NOH are designed in such a way that one is with ascorbic acid moiety and no tocopherol moiety; another is with tocopherol moiety and no ascorbic acid moiety respectively. All the three cationic lipids can form self-assembled aggregates. The antioxidant efficiencies of the three lipids were compared with free ascorbic acid. The cationic lipids (Toc-As, N14-As and Toc-NOH) were formulated individually with a well-known fusogenic co-lipid DOPE and characterization studies such as DNA binding, heparin displacement, size, charge, circular dichroism were performed. The biological characterization studies such as cell viability assay and in vitro transfection studies were carried out with the above formulations in HepG2, Neuro-2a, CHO andHEK-293T cell lines. The three formulations showed their transfection efficiencies with highest in Toc-As, moderate inN14-As and least in Toc-NOH. Interestingly, the transfection efficiency observed with the antioxidant based conjugated lipid Toc-As is found to be approximately two and half fold higher than the commercially available lipofectamine 2000 at 4:1 charge ratio in Hep G2 cell lines. In the other cell lines studied the efficiency of Toc-As is found to be either higher or similarly active compared to lipofectamine 2000. The physicochemical characterization results show that Toc-As lipid is showing maximum antioxidant potency, strong binding with pDNA, least size and optimal zeta potential. It is also found to be least toxic in all the cell lines studied especially in Neuro-2a cell lines when compared to other two lipids. In summary, the designed antioxidant lipid can be exploited as a delivering system for treating ROS related diseases such as malignancy, brain stroke, etc.
Assuntos
Ácido Ascórbico/farmacologia , DNA/química , Sequestradores de Radicais Livres/farmacologia , Lipossomos/farmacologia , Tensoativos/farmacologia , alfa-Tocoferol/farmacologia , Animais , Ácido Ascórbico/síntese química , Ácido Ascórbico/química , Ácido Ascórbico/toxicidade , Células CHO , Linhagem Celular Tumoral , Cricetulus , DNA/genética , Sequestradores de Radicais Livres/síntese química , Sequestradores de Radicais Livres/química , Sequestradores de Radicais Livres/toxicidade , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Humanos , Lipossomos/síntese química , Lipossomos/química , Lipossomos/toxicidade , Camundongos , Tensoativos/síntese química , Tensoativos/química , Tensoativos/toxicidade , Transfecção/métodos , alfa-Tocoferol/síntese química , alfa-Tocoferol/química , alfa-Tocoferol/toxicidadeRESUMO
Daidzein is a common isoflavone, having multiple biological effects such as anti-inflammation, anti-allergy, and anti-aging. α-Tocopherol is the tocopherol isoform with the highest vitamin E activity including anti-allergic activity and anti-cancer activity. Hesperetin is a flavone, which shows potent anti-inflammatory effects. These compounds have shortcomings, i.e., water-insolubility and poor absorption after oral administration. The glycosylation of bioactive compounds can enhance their water-solubility, physicochemical stability, intestinal absorption, and biological half-life, and improve their bio- and pharmacological properties. They were transformed by cultured Nicotiana tabacum cells to 7-ß-glucoside and 7-ß-gentiobioside of daidzein, and 3'- and 7-ß-glucosides, 3',7-ß-diglucoside, and 7-ß-gentiobioside of hesperetin. Daidzein and α-tocopherol were glycosylated by galactosylation with ß-glucosidase to give 4'- and 7-ß-galactosides of daidzein, which were new compounds, and α-tocopherol 6-ß-galactoside. These nine glycosides showed higher anti-allergic activity, i.e., inhibitory activity toward histamine release from rat peritoneal mast cells, than their respective aglycones. In addition, these glycosides showed higher tyrosinase inhibitory activity than the corresponding aglycones. Glycosylation of daidzein, α-tocopherol, and hesperetin greatly improved their biological activities.
Assuntos
Antialérgicos/síntese química , Cosméticos/síntese química , Glicosídeos/síntese química , Hesperidina/síntese química , Isoflavonas/síntese química , alfa-Tocoferol/síntese química , Animais , Antialérgicos/metabolismo , Biocatálise , Técnicas de Cultura de Células , Cosméticos/metabolismo , Alimento Funcional/análise , Glicosídeos/metabolismo , Glicosilação , Hesperidina/metabolismo , Humanos , Isoflavonas/metabolismo , Masculino , Mastócitos/citologia , Mastócitos/efeitos dos fármacos , Mastócitos/metabolismo , Monofenol Mono-Oxigenase/antagonistas & inibidores , Monofenol Mono-Oxigenase/metabolismo , Células Vegetais/metabolismo , Cultura Primária de Células , Ratos , Ratos Wistar , Solubilidade , Nicotiana/citologia , Nicotiana/metabolismo , alfa-Tocoferol/metabolismoRESUMO
The complete synthesis of D-α-tocopherol was achieved using our developed-Ullmann C-O coupling reaction as a key reaction. The synthesis of the core structure of D-α-tocopherol, which is a chiral chromane, has never been reported using intramolecular Ullmann C-O coupling reactions owing to the low reactivity of electron-rich iodoarenes with tertiary alcohols. Because the developed intramolecular C-O coupling reactions prefer electron-rich iodoarenes with tertiary alcohols, we successfully synthesized the chiral chromane core and achieved the total synthesis of D-α-tocopherol.
Assuntos
Cromanos/síntese química , alfa-Tocoferol/síntese química , Álcoois/química , Amidas/química , Catálise , Ciclização , Isomerismo , Estrutura Molecular , OxirreduçãoRESUMO
Amphiphilic polymer of α-tocopherol succinate modified glycol chitosan (TS-GC) was successfully constructed by conjugating α-tocopherol succinate to the skeleton of glycol chitosan and characterized by Fourier-transform infrared (FT-IR) and proton nuclear magnetic resonance (¹H-NMR). In aqueous milieu, the conjugates self-assembled to micelles with the critical aggregation concentration of 7.2 × 10−3 mg/mL. Transmission electron microscope (TEM) observation and dynamic light scattering (DLS) measurements were carried out to determine the physicochemical properties of the micelles. The results revealed that paclitaxel (PTX)-loaded TS-GC micelles were spherical in shape. Moreover, the PTX-loaded micelles showed increased particle sizes (35 nm vs. 142 nm) and a little reduced zeta potential (+19 mV vs. +16 mV) compared with blank micelles. The X-ray diffraction (XRD) spectra demonstrated that PTX existed inside the micelles in amorphous or molecular state. In vitro and in vivo tests showed that the PTX-loaded TS-GC micelles had advantages over the Cremophor EL-based formulation in terms of low toxicity level and increased dose, which suggested the potential of the polymer as carriers for PTX to improve their delivery properties.
Assuntos
Quitosana/química , Sistemas de Liberação de Medicamentos , Micelas , Paclitaxel/administração & dosagem , Polímeros/química , Animais , Antineoplásicos/farmacologia , Quitosana/síntese química , Feminino , Glicerol/análogos & derivados , Glicerol/farmacologia , Humanos , Injeções Intravenosas , Células MCF-7 , Masculino , Camundongos , Tamanho da Partícula , Polímeros/síntese química , Espectroscopia de Prótons por Ressonância Magnética , Coelhos , Espectroscopia de Infravermelho com Transformada de Fourier , Eletricidade Estática , Difração de Raios X , alfa-Tocoferol/análogos & derivados , alfa-Tocoferol/síntese química , alfa-Tocoferol/químicaRESUMO
Tertiary alcohol precursors of both C2 diastereoisomers of α-tocopherol were prepared in three ways by our recently reported asymmetric Grignard synthesis. The versatility of Grignard chemistry inherent in its three-way disconnection was exploited to allow the synthesis of three product grades: 77 : 23 dr (5 steps), 81 : 19 dr (5 steps) and 96 : 4 dr (7 steps, one gram scale) from readily available and abundant starting materials. The products were converted to their respective α-tocopherols in 3 steps, which allowed a definitive re-assignment of their absolute configurations.
Assuntos
Cetonas/química , Vitaminas/síntese química , alfa-Tocoferol/síntese química , Álcoois/síntese química , Álcoois/química , Técnicas de Química Sintética , Indicadores e Reagentes , Cetonas/síntese química , Conformação Molecular , Estereoisomerismo , Vitaminas/química , alfa-Tocoferol/químicaRESUMO
α-Tocopheryl succinate (α-TOS) is a well-known mitochondrially targeted anticancer compound, however, it is highly hydrophobic and toxic. In order to improve its activity and reduce its toxicity, new surfactant-free biologically active nanoparticles (NP) were synthesized. A methacrylic derivative of α-TOS (MTOS) was prepared and incorporated in amphiphilic pseudoblock copolymers when copolymerized with N-vinylpyrrolidone (VP) by free radical polymerization (poly(VP-co-MTOS)). The selected poly(VP-co-MTOS) copolymers formed surfactant-free NP by nanoprecipitation with sizes between 96 and 220 nm and narrow size distribution, and the in vitro biological activity was tested. In order to understand the structure-activity relationship three other methacrylic monomers were synthesized and characterized: MVE did not have the succinate group, SPHY did not have the chromanol ring, and MPHY did not have both the succinate group and the chromanol ring. The corresponding families of copolymers (poly(VP-co-MVE), poly(VP-co-SPHY), and poly(VP-co-MPHY)) were synthesized and characterized, and their biological activity was compared to poly(VP-co-MTOS). Both poly(VP-co-MTOS) and poly(VP-co-MVE) presented triple action: reduced cell viability of cancer cells with little or no harm to normal cells (anticancer), reduced viability of proliferating endothelial cells with little or no harm to quiescent endothelial cells (antiangiogenic), and efficiently encapsulated hydrophobic molecules (nanocarrier). The anticancer and antiangiogenic activity of the synthesized copolymers is demonstrated as the active compound (vitamin E or α-tocopheryl succinate) do not need to be cleaved to trigger the biological action targeting ubiquinone binding sites of complex II. Poly(VP-co-SPHY) and poly(VP-co-MPHY) also formed surfactant-free NP that were also endocyted by the assayed cells; however, these NP did not selectively reduce cell viability of cancer cells. Therefore, the chromanol ring of the vitamin E analogues has an important role in the biological activity of the copolymers. Moreover, when succinate moiety is substituted and vitamin E is directly linked to the macromolecular chain through an ester bond, the biological activity is maintained.
Assuntos
Nanopartículas/química , Relação Estrutura-Atividade , Vitamina E/síntese química , alfa-Tocoferol/síntese química , Inibidores da Angiogênese/síntese química , Inibidores da Angiogênese/química , Antineoplásicos/síntese química , Antineoplásicos/química , Proliferação de Células/efeitos dos fármacos , Humanos , Interações Hidrofóbicas e Hidrofílicas , Células MCF-7 , Metacrilatos/síntese química , Metacrilatos/química , Nanopartículas/uso terapêutico , Neoplasias/tratamento farmacológico , Neovascularização Patológica/tratamento farmacológico , Polímeros/síntese química , Polímeros/química , Tensoativos/química , Vitamina E/análogos & derivados , Vitamina E/química , Vitamina E/farmacologia , alfa-Tocoferol/análogos & derivados , alfa-Tocoferol/química , alfa-Tocoferol/farmacologiaRESUMO
By introducing a disposable activating substituent at C-3, the asymmetric 1,4-addition to a notoriously unreactive 2-substituted chromenone was achieved with high levels of (2R)-stereoselectivity in the presence of a chiral Cu(I)-phosphoramidite complex as a catalyst. This paved the way for an efficient and conceptually novel synthesis of (R,R,R)-α-tocopherol from readily available starting materials.
Assuntos
Cobre/química , alfa-Tocoferol/síntese química , Catálise , Estrutura Molecular , Estereoisomerismo , alfa-Tocoferol/químicaRESUMO
A series of naphthyridinol analogs of α-tocopherol (α-TOH, right) with varying sidechain substitution was synthesized to determine how systematic changes in the lipophilicity of these potent antioxidants impact their radical-trapping activities in lipid bilayers, regenerability by water-soluble reductants, and binding to human tocopherol transport protein (TTP). The activities of the naphthyridinols were assayed in phosphatidylcholine unilamellar liposomes using a recently developed high-throughput assay that employs a boron dipyrromethene conjugate of α-TOH (H(2)B-PMHC) that undergoes fluorescence enhancement upon oxidation. The naphthyridinols afforded a dose-dependent protection of H(2)B-PMHC consistent with unprecedented peroxyl radical-trapping activity in lipid bilayers. While sidechain length and/or branching had no effect on their apparent reactivity, it dramatically impacted reaction stoichiometry, with more lipophilic compounds trapping two peroxyl radicals and more hydrophilic compounds trapping significantly less than one. It is suggested that the less lipophilic compounds autoxidize rapidly in the aqueous phase and that preferential partitioning of the more lipophilic compounds to the bilayer protects them from autoxidation. The cooperativity of a lipophilic naphthyridinol with water-soluble reducing agents was also studied in liposomes using H(2)B-PMHC and revealed superior regenerability by each of ascorbate, N-acetylcysteine, and urate when compared to α-TOH. Binding assays with human TTP, a key determinant of the bioavailability of the tocopherols, reveal that the naphthyiridinols can be very good ligands for the protein. In fact, naphthyridinols with sidechains of eight or more carbons had affinities for TTP which were similar to, and in one case 10-fold better than, α-TOH.
Assuntos
Antioxidantes/síntese química , Bicamadas Lipídicas/química , Naftiridinas/síntese química , Vitamina E/química , alfa-Tocoferol/síntese química , Antioxidantes/química , Estrutura Molecular , Naftiridinas/química , alfa-Tocoferol/químicaRESUMO
The vitamin E analogues (2R,4'R,8'R)-nor-α-tocopherol (94 % de) and (2RS,4'R,8'R)-nor-α-tocopherol have been synthesized from (all R)-hexahydrofarnesol and phytol, respectively. According to in vitro experiments with murine macrophages nor-α-tocopherol is an anti-inflammatory compound more potent than α-tocopherol.
Assuntos
Antioxidantes/síntese química , Antioxidantes/farmacologia , alfa-Tocoferol/síntese química , alfa-Tocoferol/farmacologia , Animais , Antioxidantes/química , Linhagem Celular , Citocinas/metabolismo , Inflamação/genética , Macrófagos/efeitos dos fármacos , Macrófagos/enzimologia , Macrófagos/metabolismo , Camundongos , Modelos Moleculares , Conformação Molecular , Óxido Nítrico Sintase Tipo II/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Estereoisomerismo , alfa-Tocoferol/análogos & derivados , alfa-Tocoferol/químicaRESUMO
A new synthetic route to pyrrolopyridinol antioxidants from easily accessible pyridoxine was developed which includes phase-transfer catalytic alkylation and intramolecular Cu(I)-catalyzed amination as key steps.
Assuntos
Piridinas/química , Piridoxina/química , Pirróis/química , alfa-Tocoferol/análogos & derivados , Hidroxilação , Estrutura Molecular , Estereoisomerismo , alfa-Tocoferol/síntese químicaRESUMO
Alpha-tocopherol was synthesized from a chiral intermediate alpha-hydroxy ester by means of two ring-closing methods to yield the chromanol in 94% diastereomeric excess.
Assuntos
alfa-Tocoferol/síntese química , Cromanos/química , Ciclização , Estereoisomerismo , alfa-Tocoferol/químicaRESUMO
A polyunsaturated analogue of alpha-tocopherol was synthesized that is both fluorescent and sensitive to peroxidative chemistry that occurs in phospholipid membranes. alpha-Tocohexaenol 1, [(S)-2,5,7,8-tetramethyl-2-((1E/Z,3E,5E,7E,9E)-4,8,12-trimethyltrideca-1,3,5,7,9,11-hexaenyl)chroman-6-ol, alpha-T6] was prepared by condensing a known triene fragment triphenyl-(2,6-dimethyl-octa-2,4,6-trienoic acid methyl ester)-phosphonium bromide with a protected chromanol aldehyde, (2S)-6-{[tert-butyl(dimethyl)silyl]oxy}-2,5,7,8-tetra-methyl-3,4-dihydro-2H-chromene-2-carbaldehyde. The full side chain was then completed with isopentyl(tri-n-butyl)phosphonium bromide to give 1. The geometry of the C1'-C2' alkene appears to be Z (cis) although the coupling constants of the olefinic protons are intermediate between values normally assigned to E and Z-isomers. In ethanol, alpha-T6 has a maximum absorption at 368nm with an absorption coefficient of 45,000M(-1) cm(-1), and displays a maximum fluorescence emission at 523nm. The susceptibility of alpha-T6 to peroxidative chemistry was dependent on the concentration of azo-initiators of lipid oxidation in acetonitrile solution as well as in phospholipid vesicles. A loss of fluorescence at 520nm was observed when alpha-T6 (vesicles or alpha-T6-lipid mixtures) was exposed to peroxidative conditions, and this loss mirrored the production of conjugated dienes and trienes during the peroxidation of bulk phospholipids. Addition of natural alpha-tocopherol during the AMVN induced oxidation of 4microM alpha-T6 and 0.5mg/ml soybean PC induced a characteristic lag phase, after which the fluorescence of alpha-T6 began to lessen. Thus, alpha-T6 may be a useful reporter not only of tocopherol location in cells, but also of the extent of peroxidative events.
Assuntos
Cromanos/síntese química , Fluorescência , Polienos/química , alfa-Tocoferol/análogos & derivados , alfa-Tocoferol/síntese química , Cromanos/química , Conformação Molecular , Oxirredução , Estereoisomerismo , alfa-Tocoferol/químicaRESUMO
An efficient synthesis has provided access to a novel α-tocopherol analogue (2), as well as its trifluoroacetate salt and acetate ester. An annulation reaction was used to establish the pyridinol core structure and a Stille coupling reaction was employed for conjugation with the tocopherol side chain. This analogue was shown to suppress the levels of reactive oxygen species in cultured cells, and to quench peroxidation of mitochondrial membranes.
Assuntos
Antioxidantes/química , Diterpenos/síntese química , Mitocôndrias/metabolismo , Piridinas/síntese química , alfa-Tocoferol/análogos & derivados , Animais , Antioxidantes/metabolismo , Bovinos , Membrana Celular/metabolismo , Diterpenos/química , Diterpenos/farmacologia , Desenho de Fármacos , Peroxidação de Lipídeos/efeitos dos fármacos , Piridinas/química , Piridinas/farmacologia , Pirimidinas/química , Pirróis/química , Espécies Reativas de Oxigênio/metabolismo , alfa-Tocoferol/síntese química , alfa-Tocoferol/farmacologiaRESUMO
PURPOSE: Among derivatives of alpha-vitamin E, alpha-vitamin E succinate (VES), has attracted much attention due to its potent anti-prostate cancer activity in vitro and in vivo. However, the in vivo antitumor activity of VES might be compromised if administrated orally due to the VES hydrolysis by esterases in the gastrointestinal tract. EXPERIMENTAL DESIGN: New nonhydrolyzable VES ether analogues were synthesized and their growth inhibition was screened by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide growth assay. Among them, RRR-alpha-tocopheryloxybutyl sulfonic acid (VEBSA) was further characterized by terminal deoxyribonucleotidyl transferase-mediated dUTP nick end labeling apoptosis assay, soft agar assay, and in vivo tumor formation. RESULTS: VEBSA has potent antitumor ability, albeit to a lesser extent than VES, in in vitro cultured prostate cancer LNCaP and PC3 cells. Like VES, VEBSA induced apoptosis, repressed androgen receptor protein expression, and enhanced vitamin D receptor expression, suggesting that VEBSA can go through mechanisms similar to those used by VES to inhibit the growth of prostate cancer cells in vitro. However, 6 weeks of oral consumption of VEBSA, but not of VES, reduced the tumor burden in the xenografted prostate tumors in nude mice. Furthermore, oral intake of VEBSA for 20 weeks inhibited prostate tumor growth and progression more efficiently compared with VES in the prostate cancer tumor model of TRAMP mice. CONCLUSION: Oral consumption of VEBSA allows a greater anticancer activity compared with VES. Chemoprevention prefers the oral consumption of agents; the advantage of VEBSA over VES to be administrated orally will allow VEBSA to serve as an agent for both preventive and therapeutic purposes for prostate cancer.
Assuntos
Neoplasias da Próstata/tratamento farmacológico , Vitamina E/análogos & derivados , Administração Oral , Animais , Apoptose , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Avaliação Pré-Clínica de Medicamentos , Humanos , Masculino , Camundongos , Camundongos Nus , Neoplasias da Próstata/metabolismo , Receptores Androgênicos/metabolismo , Receptores de Calcitriol/metabolismo , Ácidos Sulfônicos/síntese química , Ácidos Sulfônicos/uso terapêutico , Vitamina E/administração & dosagem , Vitamina E/uso terapêutico , Ensaios Antitumorais Modelo de Xenoenxerto , alfa-Tocoferol/análogos & derivados , alfa-Tocoferol/síntese química , alfa-Tocoferol/uso terapêuticoRESUMO
Bio-availability of different alpha-tocopherol forms in livestock animals is measured by the increase in plasma or tissue concentrations of alpha-tocopherol after oral administration. It is generally accepted that RRR-alpha-tocopheryl acetate (natural source vitamin E derived from vegetable oil) has a higher bio-availability compared to all-rac-alpha-tocopheryl acetate (synthetic vitamin E, i.e. alpha-tocopherol produced by chemical synthesis). However, different bio-availability ratios have been reported in the literature. The major reason for conflicting results in literature studies was the inability to separate the proportion of alpha-tocopherol originating from test materials, from the proportion of alpha-tocopherol originating from basal dietary ingredients and pre-feeding. This causes significant variability. For bio-availability determination, a baseline or control treatment is essential. The estimation of bio-availability without correction for basal vitamin E status will lead to incorrect interpretation of the results. When using proper methodologies, it is possible to correct for the impact of alpha-tocopherol intake from basal ingredients and alpha-tocopherol originating from pre-feeding, therefore yielding results reflecting the true relative bio-availability of different alpha-tocopherol substances. When reviewing literature data a critical evaluation of the method used in determination of relative bio-availability is recommended.
Assuntos
Projetos de Pesquisa/normas , alfa-Tocoferol/farmacocinética , Animais , Disponibilidade Biológica , alfa-Tocoferol/administração & dosagem , alfa-Tocoferol/síntese químicaRESUMO
We report here on our efforts to develop new strategies for the synthesis of alpha-tocopherol, the biologically most significant member of the vitamin E family. This review comprises five new methods to generate the chiral chromane of alpha-tocopherol with overall up to 29% yield from commercially available material and up to 94% de.
Assuntos
Antioxidantes/síntese química , alfa-Tocoferol/síntese química , Antioxidantes/química , Catálise , Cromanos/química , Conformação Molecular , Mimetismo Molecular , Prolina/análogos & derivados , Estereoisomerismo , alfa-Tocoferol/químicaRESUMO
BACKGROUND/AIMS: Free radicals, in a colon, may damage DNA, make difficult DNA repair and change course of post-translational modifications of regulatory proteins, which promote tumor initiation and progression. Therefore risk of colon cancer is closely related to diet and other lifestyle factors. Dietary antioxidants, such as vitamin E, should reduce the levels of harmful oxidation products. However vitamin E is not soluble in water, which decreases its bioavailability. As O-glycosides of alpha-tocopherol are better soluble in water and penetrate to tissues easier than free alpha-tocopherol, the aim of our work was to investigate the rate of release the free tocopherol from its O-glycosides in colon cancer, in comparison to human healthy colon tissue. METHODOLOGY: The activities of enzymes catalysing hydrolysis of alpha-tocopheryl glucoside (1a) and mannoside (1b) as well as p-nitrophenyl beta-glucoside (2a) and mannoside (2b) in cancer and healthy human colon tissues, were determined according to the modified method described by Zwierz et al. RESULTS: The alpha-tocopherol and p-nitrophenol were significantly better released from the respective glucosides and mannosides in cancer tissue than in "healthy" human colon tissues, with p = 0.000947 for la, p = 0.033024 for 1b; p = 0.0028 for 2a, and p = 0.0033 for 2b, respectively. CONCLUSION: Alpha-tocopherol and p-nitrophenol are released from the O-glycosides of glucose and mannose in significantly higher amount in colon cancer than in healthy tissues. The alpha-tocopherol O-glycosides can be considered as prodrugs in prevention and treatment of the colon cancer.
Assuntos
Antioxidantes/metabolismo , Colo/metabolismo , Neoplasias do Colo/metabolismo , Glicosídeos/metabolismo , alfa-Tocoferol/metabolismo , Antioxidantes/síntese química , Cromatografia Líquida de Alta Pressão , Glicosídeos/síntese química , Humanos , Manosidases/síntese química , Manosidases/metabolismo , Estrutura Molecular , Nitrofenóis/síntese química , Nitrofenóis/metabolismo , alfa-Tocoferol/síntese químicaRESUMO
AIM: To determine whether the use of a mixed polymeric micelle delivery system based on vitamin E succinate (VES)-grafted-chitosan oligosaccharide (CSO)/VES-grafted-chitosan (CS) mixed micelles (VES-g-CSO/VES-g-CS MM) enhances the delivery of C-DMSA, a theranostic fluorescent probe, for Hg2+ detection and detoxification in vitro and in vivo. METHODS: Mixed micelles self-assembled from two polymers, VES-g-CSO and VES-g-CS, were used to load C-DMSA and afforded C-DMSA@VES-g-CSO/VES-g-CS MM for cell and in vivo applications. Fluorescence microscopy was used to assess C-DMSA cellular uptake and Hg2+ detection in L929 cells. C-DMSA@VES-g-CSO/VES-g-CS MM was then administered intravenously. Hg2+ detection was assessed by fluorescence microscopy in terms of bio-distribution while detoxification efficacy in Hg2+-poisoned rat models was evaluated in terms of mercury contents in blood and in liver. RESULTS: The C-DMSA loaded mixed micelles, C-DMSA@VES-g-CSO/VES-g-CS MM, significantly enhanced cellular uptake and detoxification efficacy of C-DMSA in Hg2+ pretreated human L929 cells. Evidence from the reduction of liver coefficient, mercury contents in liver and blood, alanine transaminase and aspartate transaminase activities in Hg2+ poisoned SD rats treated with the mixed micelles strongly supported that the micelles were effective for Hg2+ detoxification in vivo. Furthermore, ex vivo fluorescence imaging experiments also supported enhanced Hg2+ detection in rat liver. CONCLUSION: The mixed polymeric micelle delivery system could significantly enhance cell uptake and efficacy of a theranostic probe for Hg2+ detection and detoxification treatment in vitro and in vivo. Moreover, this nanoparticle drug delivery system could achieve targeted detection and detoxification in liver.