Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 29
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
J Food Sci ; 81(3): E627-36, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26890337

RESUMO

Buckwheat (BF) and millet (MF) are recommended as healthy foods due to their unique chemical composition and health benefits. This study investigated the thermal and rheological properties of BF-WF (wheat flour) and MF-WF flour blends at various ratios (0:100 to 100:0). Increasing BF or MF concentration led to higher cold paste viscosity and setback viscosity of pasting properties gel adhesiveness, storage modulus (G') and loss modulus (G″) of dynamic oscillatory rheology, and yield stress (σ0 ) of flow curve of WF. BF and MF addition decreased peak viscosity and breakdown of pasting, gel hardness, swelling volume, and consistency coefficient (K) of flow curve of WF. Thermal properties of the blends appeared additive of that of individual flour. Nonadditive effects were observed for some property changes in the mixtures, and indicated interactions between flour components. This may provide a physicochemical basis for using BF and MF in formulating novel healthy products.


Assuntos
Fagopyrum , Farinha/análise , Manipulação de Alimentos/métodos , Milhetes , Preparações de Plantas , Triticum , Grão Comestível , Géis , Humanos , Reologia , Temperatura , Viscosidade
2.
Food Chem ; 138(2-3): 1153-61, 2013 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-23411226

RESUMO

Proanthocyanidin-containing rice varieties have been rarely reported. Antioxidant capacity, major antioxidant components, and nutritional parameters of eight traditional red-grained rice varieties containing proanthocyanidins grown in Sri Lanka were investigated. The tested traditional red varieties, on the average, had over sevenfold higher both total antioxidant capacity and phenolic content than three light brown-grained new-improved rice varieties. Major antioxidant phenolic compounds identified in this study included proanthocyanidins, phenolic acids and γ-oryzanols (ferulic acid derivatives). Proanthocyanidins were detected only in the traditional red varieties, but not found in new-improved ones. Most traditional red varieties also contained significantly higher levels of protein with well balanced amino acids and higher contents of fat, fibre and vitamin E (tocopherols and tocotrienols) than the new-improved ones. Great variations in antioxidant capacity, major phenolics, and nutritional parameters were observed among different rice varieties. These Sri Lankan traditional red-grained rice varieties containing proanthocyanidins may be used as important genetic sources for rice breeding.


Assuntos
Antioxidantes/análise , Oryza/química , Proantocianidinas/análise , Aminoácidos/análise , Fibras na Dieta/análise , Valor Nutritivo , Oryza/classificação , Fenóis/análise , Proteínas de Plantas/análise , Sri Lanka , Vitamina E/análise
3.
J Agric Food Chem ; 60(16): 4067-75, 2012 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-22497441

RESUMO

Caffeoylquinic acids and lignans in the crude extracts of both roots and seeds from different burdock ( Arctium lappa L.) genotypes were simultaneously characterized and systematically compared by LC-MS and matrix-assisted laser desorption/ionization quadrupole ion trap time-of-flight mass spectrometry (MALDI-QIT-TOF MS), and their antioxidant activities were also investigated. A total of 14 lignans were identified in burdock seeds and 12 caffeoylquinic acids in burdock roots. High levels of caffeoylquinic acids were also detected in burdock seeds, but only trace amounts of lignans were found in burdock roots. Burdock seeds contained higher concentrations of lignans and caffeoylquinic acids than burdock roots. Quantitative analysis of caffeoylquinic acids and lignans in roots and seeds of various burdock genotypes was reported for the first time. Great variations in contents of both individual and total phenolic compounds as well as antioxidant activities were found among different genotypes. Burdock as a root vegetable or medicinal plants possessed considerably stronger antioxidant activity than common vegetables and fruits.


Assuntos
Antioxidantes/análise , Arctium/química , Lignanas/análise , Extratos Vegetais/análise , Raízes de Plantas/química , Ácido Quínico/análogos & derivados , Sementes/química , Antioxidantes/metabolismo , Arctium/genética , Arctium/metabolismo , Genótipo , Lignanas/metabolismo , Extratos Vegetais/metabolismo , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , Ácido Quínico/análise , Ácido Quínico/metabolismo , Sementes/genética , Sementes/metabolismo
4.
J Sci Food Agric ; 91(13): 2477-83, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21681761

RESUMO

BACKGROUND: Dietary plant materials have attracted much attention because of their health benefits to humans. Acrylamide is found in various heated carbohydrate-rich foods. Our previous results showed that crude aqueous extracts from diverse dietary plants and some phenolic compounds could mitigate acrylamide formation in an asparagine-glucose model system. Based on our previous study, several plant materials were selected to further investigate their inhibitory effects on acrylamide formation in cookies and starch-based model systems. RESULTS: Addition of raw powders from selected dietary plants and their crude aqueous extracts could considerably reduce acrylamide formation in both cookie and potato starch-based models. Aqueous extracts of clove at 4% caused the largest reduction (50.9%) of acrylamide in cookies, whereas addition of 2% proanthocyanidins from grape seeds gave the greatest acrylamide reduction (62.2%) in a starch-based model system. CONCLUSION: It may be feasible to use some of the tested dietary plant materials to reduce acrylamide formation in cookies and other starchy foods.


Assuntos
Acrilamida/química , Farinha/análise , Aditivos Alimentares/química , Modelos Químicos , Extratos Vegetais/química , Plantas Comestíveis/química , Amido/química , Acrilamida/análise , Fast Foods/análise , Flores/química , Flores/crescimento & desenvolvimento , Frutas/química , Raízes de Plantas/química , Proantocianidinas/química , Solanum tuberosum/química , Especiarias/análise , Syzygium/química , Vitis/química , Água/química
5.
J Med Food ; 14(3): 284-90, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21142945

RESUMO

This study investigated the antibacterial efficiency of five spice and herb extracts (cinnamon stick, oregano, clove, pomegranate peel, and grape seed) against Listeria monocytogenes, Staphylococcus aureus, and Salmonella enterica in cheese at room temperature (~ 23°C). The lipid oxidation (thiobarbituric acid-reactive substances) of cheese was periodically tested by oxidative analyses. The results showed that all five plant extracts were effective against three foodborne pathogens in cheese. Treatments with these extracts increased the stability of cheese against lipid oxidation. Clove showed the highest antibacterial and antioxidant activity. The reduction of foodborne pathogen numbers and the inhibition of lipid oxidation in cheese indicated that the extracts of these plants (especially clove) have potential as natural food preservatives.


Assuntos
Antibacterianos/farmacologia , Antioxidantes/farmacologia , Queijo/microbiologia , Microbiologia de Alimentos , Conservação de Alimentos/métodos , Extratos Vegetais/farmacologia , Syzygium , Bactérias/efeitos dos fármacos , Peroxidação de Lipídeos/efeitos dos fármacos , Especiarias
6.
J Sci Food Agric ; 90(13): 2254-62, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20629114

RESUMO

BACKGROUND: Potato is consumed as an important source of carbohydrate and other nutrients as well as a good source of phenolics. Acrylamide is a potential carcinogen formed during frying of potato products. This study investigated the compositions of phenolic compounds, amino acids and reducing sugars in 16 commercial potato varieties from eight countries and analysed the relationships between these compositions and the levels of acrylamide generated by heating (185 °C, 25 min) potato powders. RESULTS: Major phenolic compounds in the tested potato varieties were identified as hydroxycinnamoylquinic/hydroxycinnamoyl derivatives by liquid chromatography/mass spectrometry. Great variations in the contents of phenolic compounds, free reducing sugars and amino acids as well as wide variations in acrylamide concentration were found among the different potato varieties. Correlation analysis revealed that fructose (r = 0.956***), glucose (r = 0.826***) and asparagine (r = 0.842***) were positively correlated with acrylamide formation. Interestingly, it was observed that higher levels of phenolic compounds were related to lower levels of acrylamide (r = - 0.692*). CONCLUSION: Careful selection of potato varieties with lower levels of fructose, glucose and asparagine and higher levels of phenolic compounds may mitigate acrylamide formation during thermal processing of potato products.


Assuntos
Acrilamida/análise , Aminoácidos/análise , Contaminação de Alimentos , Frutose/análise , Glucose/análise , Fenóis/análise , Solanum tuberosum/química , Acrilamida/química , Asparagina/análise , Carcinógenos/análise , Carcinógenos/química , Cromatografia Líquida de Alta Pressão , Cinamatos/análise , Cinamatos/química , Contaminação de Alimentos/prevenção & controle , Hong Kong , Temperatura Alta/efeitos adversos , Espectrometria de Massas , Fenóis/química , Tubérculos/química , Especificidade da Espécie
7.
J Agric Food Chem ; 58(13): 7588-96, 2010 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-20524661

RESUMO

Anthocyanins and hydroxycinnamic acid derivatives in the crude extracts of peel, flesh, and whole roots of 10 Chinese purple-fleshed sweetpotato genotypes were simultaneously characterized by liquid chromatography-photodiode array detector-atmospheric pressure chemical ionization-mass spectrometry (LC-PDA-APCI-MS), as well as their antioxidant activities were systematically investigated and compared. Major anthocyanins were identified as peonidin or cyanidin 3-sophoroside-5-glucoside and their acylated derivatives, e.g., peonidin 3-sophoroside-5-glucoside, peonidin 3-(6''-p-feruloylsophoroside)-5-glucoside, and cyanidin 3-(6''-p-feruloylsophoroside)-5-glucoside, and main hydroxycinnamic acid derivatives were identified as mono- and dicaffeoylquinic acids (e.g., 5-O-caffeoylquinic acid and 3,5-di-O-caffeoylquinic acid) and caffeoyl-hexoside. These main phenolic compounds identified were important contributors to the total antioxidant capacity of the tested sweetpotato samples. Additionally, great variations in contents of both total and individual phenolic compounds as well as antioxidant activities between different genotypes and among various parts of the roots were observed. This study may provide value information for breeding new lines of Chinese purple-fleshed sweetpotato and also for quality control of bioactive components during production and processing.


Assuntos
Antocianinas/análise , Antioxidantes/análise , Ácidos Cumáricos/análise , Ipomoea batatas/química , Extratos Vegetais/análise , Genótipo , Ipomoea batatas/genética , Raízes de Plantas/química , Raízes de Plantas/genética
8.
Eur J Pharmacol ; 641(2-3): 102-7, 2010 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-20553913

RESUMO

Gallic acid, an organic acid, also known as 3,4,5-trihydroxybenzoic acid, is cytotoxic against certain cancer cells, without harming normal cells. The objective of this study is to evaluate whether gallic acid can inhibit glioma cell viability, proliferation, invasion and reduce glioma cell mediated angiogenesis. Treatment of U87 and U251n glioma cells with gallic acid inhibited cell viability in a dose-dependent manner. BrdU and tube formation assays indicated that gallic acid significantly decreased glioma cell proliferation and tube formation in mouse brain endothelial cells, respectively. In addition, gallic acid decreased U87 cell invasion in vitro. Western blot analysis showed that expression of ADAM17, p-Akt and p-Erk was suppressed by gallic acid in both U87 and U251n cell lines. These data suggest that suppression of ADAM17 and downregulation of PI3K/Akt and Ras/MAPK signaling pathways may contribute to gallic acid-induced decrease of invasiveness. Gallic acid may be a valuable candidate for treatment of brain tumor.


Assuntos
Neoplasias Encefálicas/patologia , Ácido Gálico/metabolismo , Glioma/patologia , Neoplasias/patologia , Animais , Western Blotting , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Linhagem Celular , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/genética , Relação Dose-Resposta a Droga , Regulação para Baixo , Células Endoteliais/metabolismo , Células Endoteliais/patologia , Ácido Gálico/farmacologia , Glioma/genética , Glioma/metabolismo , Humanos , Camundongos , Neovascularização Patológica/metabolismo , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo
9.
Nat Prod Res ; 24(3): 206-21, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20140800

RESUMO

The subfamily Asclepiadoideae (Apocynaceae) and the closely-related Periplocoideae are sources of many indigenous Indian medicinal plants. We surveyed antioxidant properties and total phenolic and flavonoid contents of 15 samples, representing 12 Indian medicinal plant species from these subfamilies. Total antioxidant assay was performed using the 2,2-azinobis-3-ethylbenzothiazoline-6-sulfonic acid and ferric-reducing antioxidant power methods. Total phenolic and flavonoid contents were measured using colourimetric methods. Principal phenolic compounds were detected by liquid chromatography-mass spectrometry (LC-MS). The highest antioxidant capacity and high levels of total phenolics and flavonoids were found in the leaves of Decalepis hamiltonii. The stems of Sarcostemma brevistigma exhibited the highest xanthine oxidase (XO) inhibitory activity. The roots of Hemidesmus indicus showed the highest OH(-) radical scavenging activity. In general, Periplocoideae members exhibited higher antioxidant activity than Asclepiadoideae members. The highly significant and positive correlations (R > 0.914) between total antioxidant capacity parameters and total phenolic content indicated that the phenolic compounds contributed significantly to the antioxidant activity of the tested plant samples. The principal phenolic phytochemicals from these plants were identified by LC-MS, including flavonoids, phenolic acids and phenolic terpenoids. Chlorogenic acid and rutin were detected in almost all of the plant samples. The LC-MS analysis provided full fingerprints of the principal phenolic compounds in the medicinal plants from these two subfamilies, which are useful for their authentication and quality evaluation.


Assuntos
Antioxidantes/química , Antioxidantes/farmacologia , Apocynaceae/química , Flavonoides/química , Fenóis/química , Plantas Medicinais/química , Benzotiazóis , Cromatografia Líquida , Flavonoides/farmacologia , Sequestradores de Radicais Livres , Radical Hidroxila , Espectrometria de Massas , Medicina Tradicional , Fenóis/farmacologia , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Ácidos Sulfônicos , Tiazóis
10.
Nutr Cancer ; 62(1): 1-20, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20043255

RESUMO

Natural phenolic compounds play an important role in cancer prevention and treatment. Phenolic compounds from medicinal herbs and dietary plants include phenolic acids, flavonoids, tannins, stilbenes, curcuminoids, coumarins, lignans, quinones, and others. Various bioactivities of phenolic compounds are responsible for their chemopreventive properties (e.g., antioxidant, anticarcinogenic, or antimutagenic and anti-inflammatory effects) and also contribute to their inducing apoptosis by arresting cell cycle, regulating carcinogen metabolism and ontogenesis expression, inhibiting DNA binding and cell adhesion, migration, proliferation or differentiation, and blocking signaling pathways. This review covers the most recent literature to summarize structural categories and molecular anticancer mechanisms of phenolic compounds from medicinal herbs and dietary plants.


Assuntos
Anticarcinógenos , Fenóis , Plantas Comestíveis/química , Plantas Medicinais/química , Anti-Inflamatórios , Anticarcinógenos/química , Anticarcinógenos/farmacologia , Antimutagênicos , Antioxidantes , Cinamatos/química , Cinamatos/farmacologia , Grão Comestível/química , Flavonoides/química , Flavonoides/farmacologia , Frutas/química , Lignanas/química , Lignanas/farmacologia , Estrutura Molecular , Fenóis/química , Fenóis/farmacologia , Quinonas/química , Quinonas/farmacologia , Especiarias/análise , Taninos/química , Taninos/farmacologia , Verduras/química
11.
J Med Food ; 12(4): 695-703, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19735167

RESUMO

Lycium barbarum polysaccharides (LBPs) are important functional constituents in red-colored fruits of L. barbarum (Guo Qi Zi, a well-known traditional Chinese medicinal plant commonly known as Goji berry or wolfberry). The influence of LBP on human prostate cancer cells was systematically investigated in vitro and in vivo. The in vitro effects of LBP on two cell lines (PC-3 and DU-145) were examined by using trypan blue exclusion staining, single-cell gel electrophoresis, flow cytometry, terminal dUTP nick-end labeling assay, and immunohistochemical assay (assessment of Bcl-2 and Bax expression). The in vivo effect of LBP on PC-3 cells was assessed in the nude mouse xenograft tumor model. The in vitro results showed that LBP can dose- and time-dependently inhibit the growth of both PC-3 and DU-145 cells. LBP caused the breakage of DNA strands of PC-3 and DU-145 cells; the tail frequency and tail length were significantly higher than that of control cells. LBP also markedly induced PC-3 and DU-145 cell apoptosis, with the highest apoptosis rates at 41.5% and 35.5%, respectively. The ratio of Bcl-2/Bax protein expression following LBP treatments decreased significantly with a dose-effect relationship, which suggested that LBP can regulate the expression of Bcl-2 and Bax to induce apoptosis of PC-3 and DU-145 cells. The in vivo experimental results indicate that LBP might significantly inhibit PC-3 tumor growth in nude mice. Both the tumor volume and weight of the LBP treatment group were significantly lower than those of the control group.


Assuntos
Antineoplásicos Fitogênicos/uso terapêutico , Apoptose/efeitos dos fármacos , Medicamentos de Ervas Chinesas/uso terapêutico , Lycium , Fitoterapia , Próstata/efeitos dos fármacos , Neoplasias da Próstata/tratamento farmacológico , Animais , Antineoplásicos Fitogênicos/farmacologia , Linhagem Celular Tumoral , Dano ao DNA/efeitos dos fármacos , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Medicamentos de Ervas Chinesas/farmacologia , Frutas , Expressão Gênica , Genes bcl-2 , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Próstata/patologia , Neoplasias da Próstata/patologia , Proteínas Repressoras/genética , Fatores de Tempo , Ensaios Antitumorais Modelo de Xenoenxerto , Proteína X Associada a bcl-2/genética , Proteína X Associada a bcl-2/metabolismo
12.
J Agric Food Chem ; 57(14): 6082-9, 2009 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-19601659

RESUMO

A total of seven Kudingcha genotypes from three plant species (Ilex kudingcha, Ilex cornuta, and Ligustrum robustum) with different geographic origins in China were investigated for their major phenolic compounds, individual and total phenolics contents, and in vitro antioxidant properties (ABTS, DPPH, FRAP, and OH assays). LC-PDA-APCI-MS analysis showed that Kudingcha genotypes from Ilex and Ligustrum had entirely different phenolic profiles. Major phenolics in Kudingcha genotypes from two Ilex species were mono- and dicaffeoylquinic acids, whereas those in a Kudingcha genotype from Ligustrum were phenylethanoid and monoterpenoid glycosides. All Kudingcha genotypes of Ilex exhibited significantly stronger antioxidant capacities than that of Ligustrum. Within six Ilex genotypes, great variation existed in their composition of individual phenolic compounds and their antioxidant properties. The comparative data and LC fingerprints obtained in this study may provide useful information for screening and breeding of better Kudingcha genotypes and also for their authentication and quality control.


Assuntos
Antioxidantes/farmacologia , Genótipo , Ilex/química , Ligustrum/química , Fenóis/análise , Fenóis/farmacologia , China , Cromatografia Líquida , Ilex/genética , Ligustrum/genética , Espectrometria de Massas , Extratos Vegetais/química , Folhas de Planta/química
13.
Rapid Commun Mass Spectrom ; 23(11): 1678-82, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19408344

RESUMO

Chinese gall, a conventional traditional Chinese medicine, contains high levels of gallotannins. A rapid method for direct analysis of the gallotannins without using any troublesome sample pretreatments was developed using matrix-assisted laser desorption/ionization time-of-flight quadrupole ion trap mass spectrometry (MALDI-QIT-TOF MS) to successfully identify the gallotannin components in the crude extract of Chinese galls within several minutes. The high quality of the MS and MS(2) spectra acquired clearly showed that hydrolysable tannins in Chinese galls were identified as a series of the gallotannins with degrees of polymerization (DP) of 4-11 galloyl units. The MS(2) data indicated that the identified gallotannins with DP of 4-7 galloyl units had clear fragmentation with loss of 1-5 galloyl units which were further deprived of 1-3 water moieties. This technique may be used for rapid evaluation and screening of hydrolysable tannins in medicinal plants.


Assuntos
Medicamentos de Ervas Chinesas/química , Taninos Hidrolisáveis/química , Plantas Medicinais/química , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos
14.
J Agric Food Chem ; 56(17): 8212-7, 2008 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-18683942

RESUMO

The effect of betacyanin pigments from Amaranthus tricolor and Amaranthus cruentus on chromatic and physicochemical properties of three wheat flours was studied. Addition of Amaranthus betacyanins increased the gelatinization temperatures (T(o), T(p), and T(c)) of all wheat flours without altering their transition ranges (T(c)-T(o)). The melting enthalpies (DeltaH) were either increased or decreased depending on the types of flour and pigment. Amaranthus betacyanins decreased the peak viscosity (PV), hot paste viscosity (HPV), cold paste viscosity (CPV), setback (SB), and pasting time (PT) of all flours and increased the breakdown (BD). Texture profile analysis (TPA) showed that Amaranthus betacyanins decreased hardness, and gumminess, and increased cohesiveness of all gels, without altering adhesiveness. Chromatic investigation exhibited that A. tricolor and A. cruentus pigments imparted gels with red and orange-yellow hues with favorable color stability.


Assuntos
Amaranthus/química , Carbocianinas/farmacologia , Farinha/análise , Triticum/química , Fenômenos Químicos , Físico-Química , Cor , Estabilidade de Medicamentos , Termodinâmica , Viscosidade
15.
Planta Med ; 74(1): 43-9, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18067063

RESUMO

Many species of Polygonum are rich in bioactive constituents, which contribute to a wide range of medicinal properties. In this study, we assessed the scavenging activity against ABTS.+ and hydroxyl radicals, chelating activity against Fe2+, xanthine oxidase inhibition, antimicrobial activity, and total contents of phenolics and flavonoids in the extracts of leaves and stems or whole plants from four medicinal Polygonum species. Total antioxidant capacities and phenolic contents of Polygonum capitatum, Polygonum Chinensis, Polygonum cuspidatum, and Polygonum multiflorum were 74.60, 53.66, 56.22, and 14.34 mmol trolox/100 g dry weight (DW), and 8.69, 4.15, 6.33, and 1.27 g gallic acid/100 g DW, respectively, significantly higher than those of five dietary vegetables, fruits and spices (spring onion, broccoli, orange, carrot, and ginger). Major bioactive constituents in the tested plant extracts were also investigated using LC-MS. They were mainly phenolic compounds, e. g., flavonoids, phenolic acids and their derivatives, tannins, stilbenes, and anthraquinones. This study shows that, in addition to their roots, the leaves and stems of P. cuspidatum and P. capitatum also exhibit potent antioxidant properties and are a potential resource of natural bioactive antioxidants.


Assuntos
Antibacterianos/farmacologia , Sequestradores de Radicais Livres/farmacologia , Fitoterapia , Extratos Vegetais/farmacologia , Polygonum/classificação , Antibacterianos/administração & dosagem , Antibacterianos/uso terapêutico , Sequestradores de Radicais Livres/administração & dosagem , Sequestradores de Radicais Livres/uso terapêutico , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Humanos , Testes de Sensibilidade Microbiana , Extratos Vegetais/administração & dosagem , Extratos Vegetais/uso terapêutico , Folhas de Planta , Raízes de Plantas , Caules de Planta
16.
J Agric Food Chem ; 55(14): 5484-90, 2007 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-17567030

RESUMO

Cinnamomum burmannii Blume (cinnamon stick) from Indonesia is a little-investigated spice. In this study, the antibacterial activity, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) of cinnamon stick extract were evaluated against five common foodborne pathogenic bacteria (Bacillus cereus, Listeria monocytogenes, Staphylococcus aureus, Escherichia coli, and Salmonella anatum). Cinnamon stick extract exhibited significant antibacterial properties. Major compounds in cinnamon stick were tentatively identified by gas chromatography-mass spectrometry (GC-MS) and liquid chromatography (LC-MS) as a predominant volatile oil component ((E)-cinnamaldehyde) and several polyphenols (mainly proanthocyanidins and (epi)catechins). Both (E)-cinnamaldehyde and proanthocyanidins significantly contributed to the antibacterial properties. Additionally, scanning electron microscopy was used to observe morphological changes of bacteria treated with the crude extract of cinnamon stick and its major components. This study suggests that cinnamon stick and its bioactive components have potential for application as natural food preservatives.


Assuntos
Antibacterianos/farmacologia , Cinnamomum zeylanicum/química , Microbiologia de Alimentos , Casca de Planta/química , Bacillus cereus/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Listeria monocytogenes/efeitos dos fármacos , Extratos Vegetais/farmacologia , Proantocianidinas/farmacologia , Salmonella/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos
17.
Int J Food Microbiol ; 117(1): 112-9, 2007 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-17449125

RESUMO

The in vitro antibacterial activities of a total of 46 extracts from dietary spices and medicinal herbs were investigated by agar-well diffusion method against five foodborne bacteria (Bacillus cereus, Listeria monocytogenes, Staphylococcus aureus, Escherichia coli, and Salmonella anatum). Their total phenolic contents were also evaluated. Many herb and spice extracts contained high levels of phenolics and exhibited antibacterial activity against foodborne pathogens. Gram-positive bacteria were generally more sensitive to the tested extracts than Gram-negative ones. S. aureus was the most sensitive, while E. coli was the most resistant. There were highly positive relationships (R(2)=0.73-0.93) between antibacterial activities and phenolic content of the tested extracts against each bacterium. This suggested that the antibacterial activity of the tested extracts was closely associated with their phenolic constituents.


Assuntos
Antibacterianos/farmacologia , Doenças Transmitidas por Alimentos/prevenção & controle , Fenóis/farmacologia , Extratos Vegetais/farmacologia , Plantas Medicinais/química , Especiarias , Bacillus cereus/efeitos dos fármacos , Bacillus cereus/crescimento & desenvolvimento , Qualidade de Produtos para o Consumidor , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Humanos , Listeria monocytogenes/efeitos dos fármacos , Listeria monocytogenes/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana , Salmonella/efeitos dos fármacos , Salmonella/crescimento & desenvolvimento , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento
18.
J Agric Food Chem ; 54(18): 6520-6, 2006 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-16939305

RESUMO

Natural betacyanins have attracted great attention as food colorants and potential antioxidants. Matrix-assisted laser desorption/ionization quadrupole ion trap time-of-flight mass spectrometry (MALDI-QIT-TOF MS) is a new and powerful technique for the identification of low molecular weight compounds. This study is the first to employ MALDI-QIT-TOF MS to rapidly identify, within a few minutes, a great number of betacyanins in crude extracts from Amaranthus tricolor seedlings, Gomphrena globosa flowers, and Hylocereus polyrhizus fruits. The fresh crude extract samples without any purification were directly used for MALDI-QIT-TOF MS analysis with 2,5-dihydroxybenzoic acid as a matrix. The MS2 and MS3 spectrometric data acquired could provide important characteristic information for structural elucidation of the betacyanins. Fourteen free and acylated betacyanins, belonging to amaranthin-type, betanin-type, and gomphrenin-type betacyanins, respectively, were identified. However, the related isomers should be differentiated with the aid of HPLC.


Assuntos
Amaranthaceae/química , Amaranthus/química , Betacianinas/análise , Cactaceae/química , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Flores/química , Frutas/química , Plântula/química
19.
Life Sci ; 79(7): 613-21, 2006 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-16563441

RESUMO

Lycium barbarum, a famous Chinese medicinal herb, has a long history of use as a traditional remedy for male infertility. Polysaccharides are the most important functional constituent in L. barbarum fruits. We systematically investigated the effect of L. barbarum polysaccharides (LBP) on rat testis damage induced by a physical factor (43 degrees C heat exposure), on DNA damage of mouse testicular cells induced by a chemical factor (H2O2), and on sexual behavior and reproductive function of hemicastrated male rats. The results showed that LBP provided a protective effect against the testicular tissue damage induced by heat exposure. When compared with negative control, a suitable concentration of LBP significantly increased testis and epididymis weights, improved superoxide dismutase (SOD) activity, and raised sexual hormone levels in the damaged rat testes. LBP had a dose-dependent protective effect against DNA oxidative damage of mouse testicular cells induced by H2O2. LBP improved the copulatory performance and reproductive function of hemicastrated male rats, such as shortened penis erection latency and mount latency, regulated secretion of sexual hormones and increased hormone levels, raised accessory sexual organ weights, and improved sperm quantity and quality. The present findings support the folk reputation of L. barbarum fruits as an aphrodisiac and fertility-facilitating agent, and provide scientific evidence for a basis for the extensive use of L. barbarum fruits as a traditional remedy for male infertility in China.


Assuntos
Antioxidantes , Dano ao DNA/efeitos dos fármacos , Temperatura Alta/efeitos adversos , Peróxido de Hidrogênio/antagonistas & inibidores , Peróxido de Hidrogênio/toxicidade , Lycium/química , Orquiectomia , Oxidantes/toxicidade , Polissacarídeos/farmacologia , Reprodução/efeitos dos fármacos , Comportamento Sexual Animal/efeitos dos fármacos , Testículo/patologia , Animais , Genitália/efeitos dos fármacos , Genitália/crescimento & desenvolvimento , Hormônios Esteroides Gonadais/sangue , Indicadores e Reagentes , Masculino , Camundongos , Tamanho do Órgão/efeitos dos fármacos , Ratos , Ratos Wistar , Espermatozoides/efeitos dos fármacos , Testículo/citologia , Testículo/efeitos dos fármacos
20.
Life Sci ; 78(25): 2872-88, 2006 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-16325868

RESUMO

Traditional Chinese medicinal plants associated with anticancer contain a wide variety of natural phenolic compounds with various structural features and possessing widely differing antioxidant activity. The structure-radical scavenging activity relationships of a large number of representative phenolic compounds (e.g., flavanols, flavonols, chalcones, flavones, flavanones, isoflavones, tannins, stilbenes, curcuminoids, phenolic acids, coumarins, lignans, and quinones) identified in the traditional Chinese medicinal plants were evaluated using the improved ABTS*+ and DPPH methods. Different categories of tested phenolics showed significant mean differences in radical scavenging activity. Tannins demonstrated the strongest activity, while most quinones, isoflavones, and lignans tested showed the weakest activity. This study confirmed that the number and position of hydroxyl groups and the related glycosylation and other substitutions largely determined radical scavenging activity of the tested phenolic compounds. The differences in radical scavenging activity were attributed to structural differences in hydroxylation, glycosylation and methoxylation. The ortho-dihydroxy groups were the most important structural feature of high activity for all tested phenolic compounds. Other structural features played a modified role in enhancing or reducing the activity. Within each class of phenolic compounds, the structure-activity relationship was elucidated and discussed. This study reveals the structure-activity relationships of a large series of representative natural phenolic compounds more systematically and fully than previous work. Structure-radical scavenging activity relationships of some natural phenolics identified in the medicinal plants were evaluated for the first time.


Assuntos
Medicamentos de Ervas Chinesas/farmacologia , Sequestradores de Radicais Livres/farmacologia , Medicina Tradicional Chinesa , Fenóis/farmacologia , Plantas Medicinais/química , Medicamentos de Ervas Chinesas/química , Sequestradores de Radicais Livres/química , Radicais Livres/química , Estrutura Molecular , Fenóis/química , Relação Estrutura-Atividade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...