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1.
J Food Sci ; 84(8): 2042-2049, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31313292

RESUMO

It is important to inhibit the food-derived, potentially hazardous chemical glycated lipids by natural products. A model system was established and the products are identified to study the inhibitory mechanism of four types of catechin, resveratrol (RES), and the synthetic antioxidants butylated hydroxylanisole (BHA) and tert-butylhydroquinone (TBHQ) on the formation of carboxymethyl 1,2-dipalmitoyl-sn-glycero-3-phosphatidylethanolamine (CM-DPPE) by determining hydroxyl radical (OH·), Amadori-1,2-dipalmitoyl-sn-glycero-3-phosphatidylethanolamine (Amadori-DPPE) and glyoxal (GO). The results show that the inhibitory rates of catechin and RES on the content of CM-DPPE in the model system are higher than those of BHA and TBHQ. There are at least two inhibitory mechanisms of antioxidants on CM-DPPE. (1) Antioxidants scavenge OH·, which blocks the process of Amadori-DPPE oxidation to form CM-DPPE. (2) Antioxidants trap GO, which blocks the reaction between GO and DPPE to form CM-DPPE. This research will reveal the inhibitory mechanisms of natural antioxidants on glycated lipids from the aspect of scavenging OH· and trapping GO. PRACTICAL APPLICATION: Food manufacturers should pay attention on the production of glycated lipids in food processing. This study will provide the theoretical basis for the use of natural products to inhibit the formation of food-derived glycated lipids. Natural products, such as catechin and resveratrol, can substitute chemical synthesis antioxidants, such as butylated hydroxylanisole and tert-butylhydroquinone, in food processing, which inhibit the formation of glycated lipids.

2.
J Agric Food Chem ; 67(28): 7961-7967, 2019 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-31260294

RESUMO

Food-derived glycated phospholipids is potentially hazardous to human health. However, there are few studies on the effects of lipids on the formation of glycated phospholipids. In this work, two model systems were established: (1) a model system including 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine (PE), glucose, and Fenton reagent and (2) a model system including PE, glucose, and five kind of vegetable oils. The contents of carboxymethyl-PE, carboxyethyl-PE, Amadori-PE, hydroxyl radical (OH•), glyoxal, and methylglyoxal were determined with high-performance liquid chromatography mass spectrometry. The results of the first model system showed that OH• oxidized glucose to produce glyoxal and methylglyoxal, which then reacted with PE to form carboxymethyl-PE and carboxyethyl-PE. OH• also oxidized Amadori-PE to form carboxymethyl-PE. The results of the second model system showed that vegetable oils with higher number of moles of carbon-carbon unsaturated double bond in vegetable oil per kilogram could produce more OH•, which promote the formation of carboxymethyl-PE and carboxyethyl-PE by oxidizing glucose and oil. We elucidated the effects of oils on the formation of glycated phospholipids in terms of OH• and intermediates. This work will contribute to better understanding the formation mechanism of glycated phospholipids with oil.


Assuntos
Radical Hidroxila/química , Lipídeos/química , Fosfolipídeos/química , Cromatografia Líquida de Alta Pressão , Glucose/química , Glicosilação , Glioxal/química , Reação de Maillard , Espectrometria de Massas , Modelos Químicos , Oxirredução , Aldeído Pirúvico/química
3.
Food Funct ; 10(5): 2491-2503, 2019 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-30977506

RESUMO

It is important to inhibit food-derived potentially hazardous glycated lipids with natural products. A model reaction inhibition system was established, and products were identified with high-performance liquid chromatography-mass spectrometry (HPLC-MS/MS) to study the inhibitory effects of four types of catechins on the formation of glycated 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine (DPPE) products. The results show that the percentage inhibition of epicatechin (EC), epicatechin gallate (ECG), epigallocatechin (EGC) and epigallocatechin gallate (EGCG) on the formation of carboxymethyl 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine (CM-DPPE) are 38.84%, 33.31%, 20.71% and 22.66%, respectively. The percentage inhibition of EC, ECG, EGC and EGCG on the formation of carboxyethyl 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine (CE-DPPE) is 42.04%, 41.99%, 31.70% and 36.24%, respectively. In addition, catechin can capture glyoxal (GO) and methylglyoxal (MGO) to produce multiple products. O-Benzoquinone, the oxidation products of catechin, also captures DPPE to produce quinone-DPPE adducts. Therefore, there are two inhibitory mechanisms of tea-derived catechin for glycated DPPE: (1) catechin inhibits the formation of CM-DPPE and CE-DPPE by trapping reactive GO and MGO; and (2) catechin is oxidized to o-benzoquinone. O-Benzoquinone reacts with DPPE through nucleophilic substitution, which competes with the reaction between glucose and DPPE. This study will provide a theoretical basis for the use of natural products to inhibit the formation of food-derived glycated lipids.

4.
Biosci Biotechnol Biochem ; 83(9): 1747-1755, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31017523

RESUMO

Citrus plants are rich in flavonoids and beneficial for lipid metabolism. However, the mechanism has not been fully elucidated. Both citrus peel flavonoid extracts (CPFE) and a mixture of their primary flavonoid compounds, namely, nobiletin, tangeretin and hesperidin, citrus flavonoid purity mixture (CFPM), were found to have lipid-lowering effects on oleic acid-induced lipid accumulation in HepG2 cells. The carnitine palmitoyltransferase 1α (CPT1α) gene was markedly increased, while the fatty acid synthase (FAS) gene was significantly decreased by both CPFE and CFPM in oleic acid-treated HepG2 cells. Flavonoid compounds from citrus peel suppressed miR-122 and miR-33 expression, which were induced by oleic acid. Changes in miR-122 and miR-33 expression, which subsequently affect the expression of their target mRNAs FAS and CPT1α, are most likely the principal mechanisms leading to decreased lipid accumulation in HepG2 cells. Citrus flavonoids likely regulate lipid metabolism by modulating the expression levels of miR-122 and miR-33.


Assuntos
Citrus/química , Flavonoides/farmacologia , Metabolismo dos Lipídeos/efeitos dos fármacos , MicroRNAs/genética , Extratos Vegetais/farmacologia , Regulação para Baixo/efeitos dos fármacos , Ácido Graxo Sintase Tipo I/genética , Células Hep G2 , Humanos , Lipogênese/genética , Ácido Oleico/farmacologia , Reação em Cadeia da Polimerase em Tempo Real , Regulação para Cima/efeitos dos fármacos
5.
J Sci Food Agric ; 99(7): 3255-3263, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30549052

RESUMO

BACKGROUND: To evaluate their fat reduction effect, common carp fish protein hydrolysates (FPH) were made using four methods: the conventional enzymatic process, a microwave-intensified enzymatic process, the conventional alkaline hydrolysis process, and a microwave-intensified alkaline hydrolysis process. RESULTS: The efficiency of protein extraction was significantly enhanced by microwave intensification. The oil-holding capacities of FPH produced by these four processes were all lower than that of raw fish protein. The water-holding capacities of FPH produced by these four processes were all higher than that of raw fish protein. The FPH from the four processes and raw fish protein were used in the preparation of deep-fried kamaboko. The fat content of deep-fried kamaboko was drastically reduced from approximately 160 g kg-1 to about 50 g kg-1 by replacing 20 g kg-1 fish mince with FPH, regardless of the process. Texture profile analysis (TPA) of deep-fried kamaboko found no significant difference in hardness and brittleness among all the deep-fried kamaboko samples. The similar interior protein cross-linking micro-structure of all these samples further explained the TPA finding. CONCLUSION: With the involvement of FPH in the formulation, the fat content of deep-fried kamaboko can be significantly reduced from approximately 160 to 50 g kg-1 , without a change in its texture. © 2018 Society of Chemical Industry.


Assuntos
Culinária/métodos , Gorduras/química , Proteínas de Peixes/química , Hidrolisados de Proteína/química , Animais , Carpas , Temperatura Alta , Alimentos Marinhos/análise
6.
Arch Toxicol ; 91(12): 3737-3785, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29152681

RESUMO

Paradoxically, trichothecenes have both immunosuppressive and immunostimulatory effects. The underlying mechanisms have not been fully explored. Early studies show that dose, exposure timing, and the time at which immune function is assessed influence whether trichothecenes act in an immunosuppressive or immunostimulatory fashion. Recent studies suggest that the immunomodulatory function of trichothecenes is also actively shaped by competing cell-survival and death-signaling pathways. Autophagy may also promote trichothecene immunosuppression, although the mechanism may be complicated. Moreover, trichothecenes may generate an "immune evasion" milieu that allows pathogens to escape host and vaccine immune defenses. Some trichothecenes, especially macrocyclic trichothecenes, also potently kill cancer cells. T-2 toxin conjugated with anti-cancer monoclonal antibodies significantly suppresses the growth of thymoma EL-4 cells and colon cancer cells. The type B trichothecene diacetoxyscirpenol specifically inhibits the tumor-promoting factor HIF-1 in cancer cells under hypoxic conditions. Trichothecin markedly inhibits the growth of multiple cancer cells with constitutively activated NF-κB. The type D macrocyclic toxin Verrucarin A is also a promising therapeutic candidate for leukemia, breast cancer, prostate cancer, and pancreatic cancer. The anti-cancer activities of trichothecenes have not been comprehensively summarized. Here, we first summarize the data on the immunomodulatory effects of trichothecenes and discuss recent studies that shed light on the underlying cellular and molecular mechanisms. These mechanisms include autophagy and major signaling pathways and their crosstalk. Second, the anti-cancer potential of trichothecenes and the underlying mechanisms will be discussed. We hope that this review will show how trichothecene bioactivities can be exploited to generate therapies against pathogens and cancer.


Assuntos
Fatores Imunológicos/farmacologia , Infecção/imunologia , Tricotecenos/química , Tricotecenos/farmacologia , Anticarcinógenos/farmacologia , Autofagia/efeitos dos fármacos , Autofagia/imunologia , Humanos , Imunoglobulina A/imunologia , Imunossupressores/farmacologia , Infecção/tratamento farmacológico , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/imunologia , Relação Estrutura-Atividade
7.
Biosci Biotechnol Biochem ; 81(8): 1576-1585, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28471298

RESUMO

To establish optimal ultra-high-pressure (UHP)-assisted extraction conditions for procyanidins from lychee pericarp, a response surface analysis method with four factors and three levels was adopted. The optimum conditions were as follows: 295 MPa pressure, 13 min pressure holding time, 16.0 mL/g liquid-to-solid ratio, and 70% ethanol concentration. Compared with conventional ethanol extraction and ultrasonic-assisted extraction methods, the yields of the total procyanidins, flavonoids, and phenolics extracted using the UHP process were significantly increased; consequently, the oxygen radical absorbance capacity and cellular antioxidant activity of UHP-assisted lychee pericarp extracts were substantially enhanced. LC-MS/MS and high-performance liquid chromatography quantification results for individual phenolic compounds revealed that the yield of procyanidin compounds, including epicatechin, procyanidin A2, and procyanidin B2, from lychee pericarp could be significantly improved by the UHP-assisted extraction process. This UHP-assisted extraction process is thus a practical method for the extraction of procyanidins from lychee pericarp.


Assuntos
Flavonoides/isolamento & purificação , Frutas/química , Litchi/química , Fenóis/isolamento & purificação , Proantocianidinas/isolamento & purificação , Extração em Fase Sólida/métodos , Antioxidantes/isolamento & purificação , Etanol/química , Análise Fatorial , Fluorometria , Pressão , Espécies Reativas de Oxigênio/antagonistas & inibidores , Solventes/química , Temperatura Ambiente
8.
Anal Sci ; 33(2): 133-135, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28190829

RESUMO

In the present work, a simple design of a "label-free" fluorescence method for kanamycin was developed and explored based on a specific DNA aptamer as a recognizer and a NMM/G-quadruplex DNA system as a reporter. The titration experiment showed a linear detection range of 0.5 to 100 nM with a low detection limit of 0.5 nM. It also showed excellent selectivity in a selectivity experiment. It was then successfully employed to detect kanamycin in milk with a excellent reliability.


Assuntos
Técnicas Biossensoriais/métodos , Quadruplex G , Canamicina/análise , Limite de Detecção , Mesoporfirinas/química , Animais , Sequência de Bases , DNA/química , DNA/genética , Leite/química , Espectrometria de Fluorescência
9.
Food Funct ; 8(2): 808-815, 2017 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-28121324

RESUMO

Dietary phenolics exhibit hypolipidemic activity by changing lipid metabolism-related microRNA (miRNA) expression. Quercetin 3-O-rutinoside-7-O-α-l-rhamnosidase (quercetin 3-rut-7-rha), rutin and (-)-epicatechin are the main phenolics in lychee (Litchi chinensis Sonn.) pulp. A previous study reported that quercetin 3-rut-7-rha and rutin had hypolipidemic effects. To elucidate these effects and the underlying molecular mechanisms of lychee pulp phenolics (LPPs), the hepatic mRNA and protein expression of lipid metabolism-related genes and their associated miRNAs were measured after ten weeks of treatment with a high-fat diet (HFD) alone or in combination with LPPs. The administration of LPPs significantly reduced the HFD-induced increase in serum total cholesterol and triglyceride levels but increased the HDL-c content. The mRNA and protein expression levels of hepatic adenosine triphosphate-binding cassette transporter A1 (ABCA1) and carnitine palmitoyltransferase 1a (CPT1a) were upregulated, while fatty acid synthase (FAS) mRNA and the corresponding protein expression levels were downregulated by LPPs. Furthermore, the expression levels of miR-33, which directly modulates ABCA1 and CPT1a, and miR-122, which indirectly regulates FAS, were downregulated in mouse hepatocytes. The repression of miR-33 and miR-122 is a possible molecular mechanism of the hypolipidemic effects of LPPs in the liver. Our results suggest a novel hypolipidemic mechanism of LPPs.


Assuntos
Hiperlipidemias/tratamento farmacológico , Metabolismo dos Lipídeos/efeitos dos fármacos , Litchi/química , Fígado/metabolismo , MicroRNAs/genética , Fenóis/administração & dosagem , Extratos Vegetais/administração & dosagem , Transportador 1 de Cassete de Ligação de ATP/genética , Transportador 1 de Cassete de Ligação de ATP/metabolismo , Animais , Carnitina O-Palmitoiltransferase/genética , Carnitina O-Palmitoiltransferase/metabolismo , Dieta Hiperlipídica/efeitos adversos , Regulação para Baixo/efeitos dos fármacos , Ácido Graxo Sintases/genética , Ácido Graxo Sintases/metabolismo , Frutas/química , Humanos , Hiperlipidemias/etiologia , Hiperlipidemias/genética , Hiperlipidemias/metabolismo , Fígado/efeitos dos fármacos , Fígado/enzimologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , MicroRNAs/metabolismo
10.
Carbohydr Polym ; 152: 496-503, 2016 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-27516297

RESUMO

Three water-soluble hetero-polysaccharides, designated LP1-3, were isolated from litchi pulp. Their structures, solution properties and immunomodulatory activities were evaluated. LP1 contained (1→4,6)-ß-d-Glc and (1→4)-α-l-Gal, while LP2 contained (1→3)-α-l-Ara and (l→2)-ß-d-Gal, and LP3 contained α-l-Ara and (l→4)-ß-Rha. Their molecular weights ranged from 105,880 to 986,470g/mol. LP1 had a spherical conformation with hyper-branched structure and LP2 was semi-flexible chain, while the polysaccharide chains of LP3 were cross linked to form network-like conformation in solution. In addition, all fractions strongly stimulated mesenteric lymph node cell proliferation, IFN-γ and IL-6 secretion in the dose range of 25-100µg/mL compared with untreated control group (p<0.05). LP1 exhibited the strongest stimulation of mesenteric lymph node cell proliferation and cytokine secretion, which may be attributed to its unique chemical structure and chain conformation. This is the first report on the solution properties and intestinal immunity activities of polysaccharides from litchi pulp.


Assuntos
Frutas/química , Fatores Imunológicos , Litchi/química , Linfonodos/imunologia , Mesentério/imunologia , Polissacarídeos , Animais , Proliferação de Células/efeitos dos fármacos , Fatores Imunológicos/química , Fatores Imunológicos/isolamento & purificação , Fatores Imunológicos/farmacologia , Interferon gama/imunologia , Interleucina-6/imunologia , Linfonodos/citologia , Mesentério/citologia , Camundongos , Camundongos Endogâmicos BALB C , Polissacarídeos/química , Polissacarídeos/isolamento & purificação , Polissacarídeos/farmacologia
11.
Food Funct ; 7(1): 508-15, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26569420

RESUMO

The pulp from lychee, a tropical to subtropical fruit, contains large quantities of phenolic compounds and exhibits antioxidant activities both in vitro and in vivo. In the present study, we investigated the mechanisms underlying the hepatoprotective effects of lychee pulp phenolics (LPPs) against restraint stress-induced liver injury in mice. After 18 h of restraint stress, increased levels of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities were observed. High levels of thiobarbituric acid reactive substances (TBARS) were also found. Restraint stress causes liver damage, which was protected against by LPP pretreatment at a dosage of 200 mg (kg d)(-1) for 21 consecutive days. This treatment remarkably decreased the serum ALT, AST and TBARS levels, elevated the liver glutathione (GSH) content, and the activities of glutathione peroxidase (GPx), superoxide dismutase (SOD) and catalase (CAT). Furthermore, respiratory chain complex and Na(+)-K(+)-ATPase activities were enhanced in liver mitochondria, while mitochondrial membrane potential levels and reactive oxygen species (ROS) production decreased. Thus, treatment with LPPs ameliorated restraint stress-induced liver mitochondrial dysfunction. These results suggest that LPPs protect the liver against restraint stress-induced damage by scavenging free radicals and modulating mitochondrial dysfunction. Thus, lychee pulp may be a functional biofactor to mitigate oxidative stress.


Assuntos
Litchi/química , Hepatopatias/prevenção & controle , Doenças Mitocondriais/prevenção & controle , Fenóis/química , Extratos Vegetais/farmacologia , Restrição Física/efeitos adversos , Adenosina Trifosfatases/metabolismo , Animais , Masculino , Camundongos , Mitocôndrias Hepáticas/efeitos dos fármacos , Extratos Vegetais/química , Distribuição Aleatória , Espécies Reativas de Oxigênio
12.
Food Sci Technol Int ; 21(2): 124-32, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24367023

RESUMO

The drying kinetics of longan (Dimocarpus longan Lour.) pulp processed by microwave vacuum under different microwave levels (2.67, 5.33, 8.00, and 10.67 W/g) was investigated (pressure controlled at -85 ± 2 kPa) in the present study. It was found that the drying rate of longan pulp was dependent on the microwave power, and the rehydration rate increased from 1.96 to 2.17 with the increase of microwave power from 2.67 to 10.67 W/g. Among nine selected thin layer models, the microwave vacuum drying of longan pulp was well represented by five models, which were Page, Modified Henderson and Pabis, Wang and Singh, Logarithmic, and Midilli models. Furthermore, the results of statistical analysis indicated that the Midilli model could describe the best experimental data. In addition, scanning electron microscope observation showed that the microwave vacuum-dried longan pulp had a porous structure.


Assuntos
Dessecação/métodos , Manipulação de Alimentos/métodos , Frutas , Micro-Ondas , Sapindaceae , Humanos , Cinética , Modelos Teóricos , Vácuo
13.
Molecules ; 19(8): 12760-76, 2014 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-25140451

RESUMO

Dried litchi pulp has been used in traditional remedies in China for many years to treat various diseases, and the therapeutic activity has been, at least partly, attributed to the presence of bioactive polysaccharides. Polysaccharide-protein complexes from vacuum freeze-(VF), vacuum microwave-(VM) and heat pump (HP) dried litchi pulp, which were coded as LP-VF, LP-VM and LP-HP, were comparatively studied on the physicochemical and immunomodulatory properties. LP-HP had a predominance of galactose, while glucose was the major sugar component in LP-VF and LP-VM. Compared with LP-VF and LP-VM, LP-HP contained more aspartate and glutamic in binding protein. LP-HP also exhibited a stronger stimulatory effect on splenocyte proliferation at 200 µg/mL and triggered higher NO, TNF-α and IL-6 secretion from RAW264.7 macrophages. Different drying methods caused the difference in physicochemical properties of polysaccharide-protein complexes from dried litchi pulp, which resulted in significantly different immunomodulatory activity. HP drying appears to be the best method for preparing litchi pulp to improve its immunomodulatory properties.


Assuntos
Proliferação de Células/efeitos dos fármacos , Complexos Multiproteicos/química , Polissacarídeos/química , Baço/citologia , Animais , Antioxidantes/química , Antioxidantes/farmacologia , China , Frutas/química , Humanos , Imunomodulação/efeitos dos fármacos , Litchi/química , Camundongos , Complexos Multiproteicos/imunologia , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Polissacarídeos/imunologia
14.
Molecules ; 19(4): 3909-25, 2014 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-24691064

RESUMO

Drying is commonly used for preservation and processing of litchi. However, its polysaccharide structure may be altered by the drying process, resulting in biological activity changes. Polysaccharides from fresh and dried litchi pulp (denoted as LPF and LPD, respectively) were isolated, investigated by GC-MS, GPC and UV/IR spectrum analysis and their antitumor and immunomodulatory activities were evaluated in vitro. LPD, the molecular weight of which was lower than that of LPF, contained more protein, uronic acid, arabinose, galactose and xylose. Compared with LPF, LPD exhibited a higher inhibitory effect on the proliferation of HepG2, Hela and A549 cells from 50-750 µg/mL. LPD was also a better stimulator of spleen lymphocyte proliferation, NK cells cytotoxicity and macrophage phagocytosis from 50-400 µg/mL. In summary, drying could change the physicochemical properties and enhance the bioactivity of polysaccharides from litchi pulp. This finding is supported by the fact that dried litchi pulps are used in Traditional Chinese Medicine.


Assuntos
Antineoplásicos/química , Frutas/química , Fatores Imunológicos/química , Litchi/química , Polissacarídeos/química , Animais , Antineoplásicos/isolamento & purificação , Antineoplásicos/farmacologia , Arabinose/isolamento & purificação , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Dessecação , Galactose/isolamento & purificação , Células Hep G2 , Humanos , Fatores Imunológicos/isolamento & purificação , Fatores Imunológicos/farmacologia , Células Matadoras Naturais/citologia , Células Matadoras Naturais/efeitos dos fármacos , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Camundongos , Fagocitose/efeitos dos fármacos , Extratos Vegetais/química , Proteínas de Plantas/isolamento & purificação , Polissacarídeos/isolamento & purificação , Polissacarídeos/farmacologia , Baço/citologia , Baço/efeitos dos fármacos , Ácidos Urônicos/isolamento & purificação , Xilose/isolamento & purificação
15.
Food Chem ; 158: 385-91, 2014 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-24731359

RESUMO

Lychee pulp contains phenolic compounds that are strong antioxidants, but the identities of the major antioxidants present are unknown. In the present study, the major contributors to the antioxidant activity of fresh lychee pulp were identified and their cellular antioxidant activities were investigated. Aqueous acetone extracts of lychee pulp were fractionated on polyamide resin, and those fractions with the largest antioxidant and radical scavenging activities were selected using cellular antioxidant activity and oxygen radical absorbance capacity assays. Three compounds that were major contributors to the antioxidant activity in these fractions were obtained by reverse-phase preparative HPLC and identified as quercetin 3-O-rutinoside-7-O-α-L-rhamnosidase (quercetin 3-rut-7-rha), quercetin 3-O-rutinoside (rutin) and (-)-epicatechin using NMR spectroscopy, HMBC, and ESI-MS spectrometry. The concentration of quercetin 3-rut-7-rha was 17.25mg per 100g of lychee pulp fresh weight. This is the first report of the identification and cellular antioxidant activity of quercetin 3-rut-7-rha from lychee pulp.


Assuntos
Antioxidantes/química , Frutas/química , Litchi/química , Fenóis/análise , Oxirredução
16.
BMC Complement Altern Med ; 14: 9, 2014 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-24405977

RESUMO

BACKGROUND: The phenolic contents and antioxidant activities of fruits could be underestimated if the bound phenolic compounds are not considered. In the present study, the extraction efficiencies of various solvents were investigated in terms of the total content of the free and bound phenolic compounds, as well as the phenolic profiles and antioxidant activities of the extracts. METHODS: Five different solvent mixtures were used to extract the free phenolic compounds from litchi pulp. Alkaline and acidic hydrolysis methods were compared for the hydrolysis of bound phenolic compounds from litchi pulp residue. The phenolic compositions of the free and bound fractions from the litchi pulp were identified using HPLC-DAD. The antioxidant activities of the litchi pulp extracts were determined by oxygen radical absorbance capacity (ORAC) and cellular antioxidant activity (CAA) assays. RESULTS: Of the solvents tested, aqueous acetone extracted the largest amount of total free phenolic compounds (210.7 mg GAE/100 g FW) from litchi pulp, followed sequentially by aqueous mixtures of methanol, ethanol and ethyl acetate, and water itself. The acid hydrolysis method released twice as many bound phenolic compounds as the alkaline hydrolysis method. Nine phenolic compounds were detected in the aqueous acetone extract. In contrast, not all of these compounds were found in the other four extracts. The classification and content of the bound phenolic compounds released by the acid hydrolysis method were higher than those achieved by the alkaline hydrolysis. The aqueous acetone extract showing the highest ORAC value (3406.9 µmol TE/100 g FW) for the free phenolic extracts. For the CAA method, however, the aqueous acetone and methanol extracts (56.7 and 55.1 µmol QE/100 g FW) showed the highest levels of activity of the five extracts tested. The ORAC and CAA values of the bound phenolic compounds obtained by acid hydrolysis were 2.6- and 1.9-fold higher than those obtained using the alkaline hydrolysis method. CONCLUSIONS: The free and bound phenolic contents and profiles and antioxidant activities of the extracts were found to be dependent on the extraction solvent used. Litchi exhibited good cellular antioxidant activity and could be a potentially useful natural source of antioxidants.


Assuntos
Antioxidantes/análise , Litchi/química , Fenóis/análise , Extratos Vegetais/química , Solventes/química , Acetona/química , Antioxidantes/química , Antioxidantes/farmacologia , Cromatografia Líquida de Alta Pressão , Frutas/química , Concentração de Íons de Hidrogênio , Hidrólise , Metanol/química , Oxirredução/efeitos dos fármacos , Fenóis/química , Extratos Vegetais/farmacologia , Água/química
17.
Mol Biol Rep ; 36(8): 2265-70, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19123068

RESUMO

A high-density cell culture method was successfully established in P. pastoris with the alcohol oxidase I (AOXI) promoter in order to produce large quantities of recombinant human angiostatin (AS) which has been reported to have antiangiogenic activity. A preliminary study on fermentation conditions in shaking flasks indicated that adequacy of biomass is beneficial to obtain more products. The fermentation was carried out in a 10 l bioreactor with 5 l modified growth medium recommended by Invitrogen at 30 degrees C. The cells were first grown in glycerol-PTM4 trace salts for 24 h. When the cell density reached A(600) = 125, methanol-PTM4 trace salts was added to induce the expression of AS. During the fermentation, dissolved oxygen level was maintained at 20-30%, pH was controlled at 5 by the addition of 7 M NH(4)OH and the biomass was maintained at about A(600) = 200. After 60 h of induction, the secreted AS was 153 mg/l. The recombinant AS inhibited the angiogenesis on CAM and suppressed the growth of B16 melanoma in C57BL/6J mice (P \0.01).


Assuntos
Oxirredutases do Álcool/genética , Angiostatinas/biossíntese , Pichia/genética , Inibidores da Angiogênese/genética , Inibidores da Angiogênese/metabolismo , Inibidores da Angiogênese/farmacologia , Angiostatinas/genética , Angiostatinas/farmacologia , Animais , Reatores Biológicos , Western Blotting , Carcinoma Pulmonar de Lewis/tratamento farmacológico , Carcinoma Pulmonar de Lewis/patologia , Contagem de Células , Processos de Crescimento Celular/efeitos dos fármacos , Embrião de Galinha , Membrana Corioalantoide/irrigação sanguínea , Fermentação , Humanos , Masculino , Melanoma Experimental/tratamento farmacológico , Melanoma Experimental/patologia , Camundongos , Camundongos Endogâmicos C57BL , Neovascularização Fisiológica/efeitos dos fármacos , Pichia/enzimologia , Pichia/metabolismo , Regiões Promotoras Genéticas , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética , Proteínas Recombinantes/farmacologia
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