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1.
Biosci Biotechnol Biochem ; : 1-12, 2019 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-31282254

RESUMO

This study investigated the contents of saponins and phenolic compounds in relation to their antioxidant activity and α-glucosidase inhibition activity of 7 colored quinoa varieties. The total saponin content was significantly different among 7 varieties and ranged from 7.51 to 12.12 mg OAE/g DW. Darker quinoa had a higher content of phenolic compounds, as well as higher flavonoids and antioxidant activity than that of light varieties. Nine individual phenolic compounds were detected in free and bound form, with gallic acid and ferulic acid representing the major compounds. The free and bound phenolic compounds (gallic acid and ferulic acid in particular) exhibited high linear correlation with their corresponding antioxidant values. In addition, the free phenolic extracts from colored quinoa exhibited higher inhibitory activity against α-glucosidase than the bound phenolic extracts. These findings imply that colored quinoa with abundant bioactive phytochemicals could be an important natural source for preparing functional food.

2.
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
3.
Huan Jing Ke Xue ; 38(3): 903-910, 2017 Mar 08.
Artigo em Chinês | MEDLINE | ID: mdl-29965559

RESUMO

During the 29th Chinese National Antarctic Research Expedition (CHIANRE), individual particle samples were collected from South China to Antarctic during November 2012 to April 2013. A transmission electron microscopy with energy-dispersive X-ray spectrometry (TEM-EDS) was employed to analyze the morphology, mixing state, composition, and relative abundances of individual aerosol particles. Atmospheric particles were classified into four types:sea salt, mineral, S-rich and C-rich. Sea salt aerosols (SSA) were dominant in the marine particles from South China to Antarctic, and they were further divided into three sub-types:fresh SSA, partially aged SSA, and fully aged SSA. Partially and fully aged SSA accounted for 86% of total SSA number. Interestingly, surface of partially aged SSA and fully aged SSA contained abundant rod-like Na2SO4. Mineral dust particles increased in the coastal areas which were influenced by continental air. In addition, we found that S-rich particles were abundant at two sampling sites (the middle eastern of Indian Ocean and Antarctic inland). The back trajectories of air masses indicated that these S-rich particles were mainly formed via the oxidation of dimethyl sulfide (DMS) emitted from the marine phytoplanktons. Our study suggests that the SSA aging process in the South Hemisphere atmosphere was controlled by the DMS which is different from the SSA aging under the influence of anthropogenic pollutants in the North Hemisphere.

4.
Sci Total Environ ; 557-558: 520-30, 2016 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-27031303

RESUMO

To determine the characteristics of carbonaceous aerosols in rural areas of the North China Plain, field measurements were conducted at Yucheng (YC) in the summers of 2013 and 2014. The concentrations of carbonaceous aerosols at YC exhibited clear diurnal variation, with higher concentrations in the early morning and at night and lower concentrations during the afternoon hours. The mass-balance method designed for particulate matter smaller than 2.5µm (PM2.5) was used to calculate the organic matter (OM)/organic carbon (OC) ratio. The value obtained, 2.07±0.05, was suggested as a reference to estimate organics in PM2.5 in rural areas of the North China Plain. Biomass burning was identified to be a significant source of carbonaceous aerosols; approximately half of the samples obtained at YC were affected by biomass burning during summer 2013. Case studies revealed that biomass burning accounted for up to 52.6% of the OC and 51.1% of the elemental carbon in PM2.5 samples. The organic coatings observed on sulphur-rich and potassium-rich particles indicated the formation of secondary organic aerosols (SOA) from the oxidation of precursor volatile organic compounds (VOCs) during the aging of smoke released from biomass burning. Based on the evolution of the VOCs, the contribution of VOCs oxidation to SOA concentration was 3.21 and 1.07µgm(-3)ppm(-1) CO under conditions of low nitrogen oxide (NOx) and high NOx, respectively. Aromatics (e.g. benzene, toluene, xylene and ethylbenzene) made the greatest contribution to SOA concentration (88.4% in low-NOx conditions and 80.6% in high-NOx conditions). The results of the study offer novel insights into the effects of biomass burning on the carbonaceous aerosols and SOA formation in polluted rural areas.

5.
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
6.
Food Chem ; 178: 186-94, 2015 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-25704700

RESUMO

The phytochemical profile and antioxidant activities of unprocessed and extruded milled fractions of black rice were investigated. Extrusion increased the free phenolics, anthocyanins and oxygen radical absorbance capacity (ORAC) and decreased the bound forms. The total phenolics, anthocyanins and ORAC increased by 12.6%, 5.4% and 19.7%, respectively, in bran. Extrusion decreased both free and bound phenolics and anthocyanins while ORAC values decreased by 46.5%, 88.4% and 33.1%, respectively, in polished rice and by 71.2%, 87.9% and 14.7%, respectively, in brown rice. A total of seven phenolics, gallic, chlorogenic, vanillic, caffeic, syringic, p-coumaric and ferulic acids, were detected in both forms. Cyanidin 3-glucoside (Cy-3-G), cyanidin 3-rutinoside and peonidin 3-glucoside were also detected with Cy-3-G found in the highest amounts in unprocessed and extruded rice bran. These results provide the basis for the development of different milled fractions of extruded black rice with balanced nutritional characteristics for today's functional food markets.


Assuntos
Antioxidantes/farmacologia , Oryza/química , Extratos Vegetais/farmacologia , Antocianinas/análise , Cor , Fenóis/análise , Extratos Vegetais/análise
7.
Food Chem ; 159: 166-74, 2014 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-24767040

RESUMO

This study quantified free and bound phytochemicals and their antioxidant activity in the endosperm and bran/embryo of different indica rice varieties. Phytochemicals mainly existed as free form in the bran/embryo and as both free and bound forms in the endosperm. The average values of total phenolic content, flavonoid content, FRAP, ABTS and ORAC values in the bran/embryo were 3.1, 10.4, 8.2, 11.2 and 11.4 times higher than those in the endosperm, respectively. In whole brown rice, the bran contributed 59.2%, 53.7%, 47.7%, 55.5% and 56.9% of total phenolics, flavonoids, FRAP, ABTS and ORAC values, respectively. Seven individual phenolics (gallic, protocatechuic, chlorogenic, caffeic, syringic, coumaric and ferulic acids) were detected with most coumaric and ferulic acids in the bran. All measurements exhibited varietal differences. These findings provide important information for improving human health by encouraging the consumption of whole brown rice and its use in food product development.


Assuntos
Antioxidantes/farmacologia , Oryza/química , Fenóis/análise , Extratos Vegetais/farmacologia , China , Ácidos Cumáricos/análise , Flavonoides/análise , Humanos
8.
Molecules ; 15(4): 2152-65, 2010 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-20428034

RESUMO

Natural antioxidants such as polysaccharides with strong antioxidant activities are used to protect against oxidative damage, yet little is known so far about the antioxidant effects of litchi fruit polysaccharides. In the present study, four different polysaccharide-enriched fractions were isolated from litchi pulp tissue and partially purified by a stepwise method of ethyl alcohol (EtOH) precipitation. Their chemical and physical characteristics were determined by chemical methods, gas chromatography and IR spectrophotometry. Antioxidant activities of these fractions were investigated using various in vitro assay systems. These four polysaccharide-enriched fractions exhibited a dose-dependent free radical scavenging activity as shown by their DPPH radical, superoxide anion and hydroxyl radical inhibition, chelating ability and reducing power. Among the different fractions, LFP-III showed the strongest scavenging activity against DPPH radical, superoxide and hydroxyl radicals and chelating ability. These findings suggest litchi polysaccharides from pulp tissue have potential as functional foods with enhanced antioxidant activity.


Assuntos
Antioxidantes/farmacologia , Depuradores de Radicais Livres/farmacologia , Litchi/química , Polissacarídeos/farmacologia , Antioxidantes/química , Antioxidantes/isolamento & purificação , Etanol , Depuradores de Radicais Livres/química , Depuradores de Radicais Livres/isolamento & purificação , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Polissacarídeos/química , Polissacarídeos/isolamento & purificação
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