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1.
Plant Cell Rep ; 42(8): 1365-1378, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37269374

RESUMO

KEY MESSAGE: DcWRKY5 increases the antioxidant enzyme activity and proline accumulation, oppositely, reduces the accumulation of ROS and MDA, through directly activating the genes expression, finally enhances the salt and drought tolerance. Drought and salinity are two main environmental factors that limit the large-scale cultivation of the medicinal plant Dioscorea composita (D. composita). WRKY transcription factors (TFs) play vital roles in regulating drought and salt tolerance in plants. Nevertheless, the molecular mechanism of WRKY TF mediates drought and salt resistance of D. composita remains largely unknown. Here, we isolated and characterized a WRKY TF from D. composita, namely DcWRKY5, which was localized to the nucleus and bound to the W-box cis-acting elements. Expression pattern analysis showed that it was highly expressed in root and significantly up-regulated in the presence of salt, polyethylene glycol-6000 (PEG-6000) and abscisic acid (ABA). Heterologous expression of DcWRKY5 increased salt and drought tolerance in Arabidopsis, but was insensitive to ABA. In addition, compared with the wild type, the DcWRKY5 overexpressing transgenic lines had more proline, higher antioxidant enzyme (POD, SOD, and CAT) activities, less reactive oxygen species (ROS) and malondialdehyde (MDA). Correspondingly, the overexpression of DcWRKY5 modulated the expression of genes related to salt and drought stresses, such as AtSS1, AtP5CS1, AtCAT, AtSOD1, AtRD22, and AtABF2. Dual luciferase assay and Y1H were further confirmed that DcWRKY5 activate the promoter of AtSOD1 and AtABF2 through directly binding to the enrichment region of the W-box cis-acting elements. These results suggest that DcWRKY5 is a positive regulator of the drought and salt tolerance in D. composita and has potential applications in transgenic breeding.


Assuntos
Arabidopsis , Dioscorea , Dioscorea/genética , Dioscorea/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Secas , Tolerância ao Sal/genética , Antioxidantes/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Estresse Fisiológico/genética , Melhoramento Vegetal , Ácido Abscísico/metabolismo , Arabidopsis/genética , Regulação da Expressão Gênica de Plantas
2.
Plant Physiol Biochem ; 196: 746-758, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36827956

RESUMO

Dioscorea composita (D. composita) is an important medicinal plant worldwide with high economic value. However, its large-scale cultivation was limited by soil salinization. Identification of genes and their mechanisms of action in response to salt stress are critically important. In the present study, we isolated a classical WRKY transcription factor from D. composita, namely DcWRKY12, and analyzed its function in salt tolerance. Expression pattern analysis showed DcWRKY12 is mainly expressed in roots and significantly induced by NaCl, polyethylene glycol-6000 (PEG-6000), and abscisic acid (ABA). Phenotypic and physiological analyses revealed that heterologous expression of DcWRKY12 enhanced salt and osmotic stress tolerance by increasing antioxidant enzyme activity, osmoregulatory substance content, maintaining relative water content and ion homeostasis, decreasing reactive oxygen species and malondialdehyde content. Correspondingly, the overexpression of DcWRKY12 modulated the expression of salt stress-responsive and ion transport-related genes. Dual luciferase assay and Y1H were further confirmed that DcWRKY12 activates the promoter of AtRCI2A through directly binding to the specific W-box cis-acting elements. These results suggest that DcWRKY12 is a positive regulator of salt tolerance in D. composita and has potential applications in salt stress.


Assuntos
Arabidopsis , Dioscorea , Arabidopsis/genética , Dioscorea/genética , Dioscorea/metabolismo , Tolerância ao Sal , Estresse Fisiológico/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Ácido Abscísico/metabolismo , Regulação da Expressão Gênica de Plantas , Plantas Geneticamente Modificadas/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
3.
Int J Med Sci ; 19(12): 1806-1815, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36313224

RESUMO

Hepatocellular carcinoma (HCC) is a primary liver cancer commonly found in adults. Previously, we showed the anticancer effects of Thai herbal plant extract, Dioscorea membranacea Pierre (DM), in HCC-bearing rats. In the present study, we further examined the proposed mechanism of DM, including apoptosis and antioxidant activity. Moreover, we used RNA sequencing (RNA-seq) to analyze molecular pathways in the rat model in which HCC was induced by diethylnitrosamine (DEN) and thioacetamide (TAA). The HCC-bearing rats were then treated with 40 mg/kg of DM for 8 weeks, after which experimental and control rats were sacrificed and liver tissues were collected. The RNA-seq data of DEN/TAA-treated rats exhibited upregulation of 16 hallmark pathways, including epithelial mesenchymal transition, inflammatory responses, and angiogenesis (p<0.01). DM extract expanded the Bax protein-positive pericentral zone in the tumor areas and decreased hepatic malondialdehyde levels, implying a decrease in lipid peroxidation in liver. However, DM treatment did not ameliorate the molecular pathways induced in DEN/TAA-treated livers. Our findings indicate that DM extract has antioxidant activity and exerts its pro-apoptotic effect on rat HCCs in vivo at the (post-)translational level.


Assuntos
Carcinoma Hepatocelular , Dioscorea , Neoplasias Hepáticas , Ratos , Animais , Carcinoma Hepatocelular/induzido quimicamente , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/genética , Tioacetamida/toxicidade , Tioacetamida/metabolismo , Dietilnitrosamina/toxicidade , Dietilnitrosamina/metabolismo , Dioscorea/metabolismo , Antioxidantes/farmacologia , Neoplasias Hepáticas/induzido quimicamente , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/genética , Fígado/patologia , Extratos Vegetais/efeitos adversos
4.
Plant J ; 109(4): 940-951, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34816537

RESUMO

Diosgenin is an important compound in the pharmaceutical industry and it is biosynthesized in several eudicot and monocot species, herein represented by fenugreek (a eudicot), and Dioscorea zingiberensis (a monocot). Formation of diosgenin can be achieved by the early C22,16-oxidations of cholesterol followed by a late C26-oxidation. This study reveals that, in both fenugreek and D. zingiberensis, the early C22,16-oxygenase(s) shows strict 22R-stereospecificity for hydroxylation of the substrates. Evidence against the recently proposed intermediacy of 16S,22S-dihydroxycholesterol in diosgenin biosynthesis was also found. Moreover, in contrast to the eudicot fenugreek, which utilizes a single multifunctional cytochrome P450 (TfCYP90B50) to perform the early C22,16-oxidations, the monocot D. zingiberensis has evolved two separate cytochrome P450 enzymes, with DzCYP90B71 being specific for the 22R-oxidation and DzCYP90G6 for the C16-oxidation. We suggest that the DzCYP90B71/DzCYP90G6 pair represent more broadly conserved catalysts for diosgenin biosynthesis in monocots.


Assuntos
Dioscorea/metabolismo , Diosgenina/metabolismo , Hidroxicolesteróis/metabolismo , Trigonella/metabolismo , Vias Biossintéticas , Colesterol , Sistema Enzimático do Citocromo P-450/metabolismo , Hidroxilação , Oxigenases/metabolismo , Extratos Vegetais
5.
Int J Mol Sci ; 22(20)2021 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-34681613

RESUMO

Dioscorea zingiberensis is a medicinal herb containing a large amount of steroidal saponins, which are the major bioactive compounds and the primary storage form of diosgenin. The CYP72A gene family, belonging to cytochromes P450, exerts indispensable effects on the biosynthesis of numerous bioactive compounds. In this work, a total of 25 CYP72A genes were identified in D. zingiberensis and categorized into two groups according to the homology of protein sequences. The characteristics of their phylogenetic relationship, intron-exon organization, conserved motifs and cis-regulatory elements were performed by bioinformatics methods. The transcriptome data demonstrated that expression patterns of DzCYP72As varied by tissues. Moreover, qRT-PCR results displayed diverse expression profiles of DzCYP72As under different concentrations of jasmonic acid (JA). Likewise, eight metabolites in the biosynthesis pathway of steroidal saponins (four phytosterols, diosgenin, parvifloside, protodeltonin and dioscin) exhibited different contents under different concentrations of JA, and the content of total steroidal saponin was largest at the dose of 100 µmol/L of JA. The redundant analysis showed that 12 DzCYP72As had a strong correlation with specialized metabolites. Those genes were negatively correlated with stigmasterol and cholesterol but positively correlated with six other specialized metabolites. Among all DzCYP72As evaluated, DzCYP72A6, DzCYP72A16 and DzCYP72A17 contributed the most to the variation of specialized metabolites in the biosynthesis pathway of steroidal saponins. This study provides valuable information for further research on the biological functions related to steroidal saponin biosynthesis.


Assuntos
Ciclopentanos/farmacologia , Sistema Enzimático do Citocromo P-450/genética , Dioscorea/efeitos dos fármacos , Oxilipinas/farmacologia , Proteínas de Plantas/genética , Saponinas/metabolismo , Sequência de Aminoácidos , Sistema Enzimático do Citocromo P-450/classificação , Sistema Enzimático do Citocromo P-450/metabolismo , Dioscorea/química , Dioscorea/genética , Dioscorea/metabolismo , Diosgenina/metabolismo , Filogenia , Fitosteróis/metabolismo , Proteínas de Plantas/classificação , Proteínas de Plantas/metabolismo , Plantas Medicinais/química , Plantas Medicinais/metabolismo , Regiões Promotoras Genéticas , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Alinhamento de Sequência
6.
Food Chem ; 298: 125063, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31260979

RESUMO

Dioscorea opposita Thunb. cv. Tiegun (DTT), a type of homologous medicinal plant, is commonly used as food in daily life. However, there has always been confusion regarding removal of the peel, as the nutrient metabolite composition of the peel is unclear. Here, a nuclear magnetic resonance (NMR)-based metabolomics approach was used to determine the metabolite distribution in DTT exclude-peel and peel. Thirteen characteristic metabolites with statistical significance were identified and compared using multivariate, univariate and cluster analyses. The results demonstrated that the peel contained the higher levels of α-glucose, batatasin IV, batatasin I, asparagine, ß-glucose, protodioscin, threonine, protogracillin, dioscin, and ß-sitosteryl acetate, and the samples without the peel had the higher levels of leucine, glutamine and alanine. This study provided scientific data for understanding the distribution characteristics of metabolites in DTT samples, promoting reasonable consumption of DTT.


Assuntos
Dioscorea/metabolismo , Metabolômica/métodos , Análise por Conglomerados , Diosgenina/análogos & derivados , Diosgenina/química , Diosgenina/metabolismo , Leucina/metabolismo , Espectroscopia de Ressonância Magnética , Exsudatos de Plantas/metabolismo , Plantas Medicinais/metabolismo , Análise de Componente Principal , Saponinas/química , Saponinas/metabolismo
7.
Biochem Biophys Res Commun ; 509(3): 822-827, 2019 02 12.
Artigo em Inglês | MEDLINE | ID: mdl-30638657

RESUMO

Dioscorea zingiberensis is a perennial medicinal herb rich in a variety of pharmaceutical steroidal saponins. Squalene epoxidase (SE) is the key enzyme in the biosynthesis pathways of triterpenoids and sterols, and catalyzes the epoxidation of squalene in coordination with NADPH-cytochrome P450 reductase (CPR). In this study, we cloned DzSE and DzCPR gene sequences from D. zingiberensis leaves, encoding proteins with 514 and 692 amino acids, respectively. Recombinant proteins were successfully expressed in vitro, and enzymatic analysis indicated that, when SE and CPR were incubated with the substrates squalene and NADPH, 2,3-oxidosqualene was formed as the product. Subcellular localization revealed that both the DzSE and DzCPR proteins are localized to the endoplasmic reticulum. The changes in transcription of DzSE and DzCPR were similar in several tissues. DzSE expression was enhanced in a time-dependent manner after methyl jasmonate (MeJA) treatments, while DzCPR expression was not inducible.


Assuntos
Dioscorea/enzimologia , NADPH-Ferri-Hemoproteína Redutase/metabolismo , NADP/metabolismo , Proteínas de Plantas/metabolismo , Esqualeno Mono-Oxigenase/metabolismo , Esqualeno/metabolismo , Acetatos/metabolismo , Ciclopentanos/metabolismo , Dioscorea/genética , Dioscorea/metabolismo , Regulação da Expressão Gênica de Plantas , NADPH-Ferri-Hemoproteína Redutase/genética , Oxilipinas/metabolismo , Proteínas de Plantas/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Esqualeno/análogos & derivados , Esqualeno Mono-Oxigenase/genética
8.
Curr Med Chem ; 25(42): 5986-6001, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29768998

RESUMO

Lectins are a group of proteins or glycoproteins with various potentially exploitable bioactivities and have been capturing more interest recently. They have been isolated and reported from various tissues of a diversity of plant species. Tubers are modified and enlarged plant structures derived from stems or roots that are used for nutrient storage and asexual reproduction. A number of plants such as yam, taro and potato are grown for their edible tubers, and lectins are found to be one of the major storage proteins. These lectins exhibit potent bioactivities encompassing mitogenic, antitumor, antimicrobial, immunomodulatory, antioxidative, hypoglycemic, insecticidal and nematicidal activities. They are potential resources for development into functional or healthy foods and targets for food protein researchers.


Assuntos
Lectinas/metabolismo , Arisaema/metabolismo , Dioscorea/metabolismo , Lectinas/química , Tubérculos/metabolismo , Solanum tuberosum/metabolismo , Trichosanthes/metabolismo
9.
Food Funct ; 9(4): 2416-2425, 2018 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-29620784

RESUMO

The in vitro prebiotic effects of resistant starch (RS), prepared by different treatments from purple yam, on Bifidobacterium adolescentis (bifidobacteria for short), were investigated. Tolerance tests indicated that bifidobacteria in PDS (prepared by debranching combined with autoclaving) and PDS.H (PDS further treated by double enzyme hydrolysis) media adapted better to simulated upper gastrointestinal conditions (at pH 1.5-3.0 and 0.3% and 1.0% bile acid) than those in GLU (glucose) and DAS (prepared by autoclaving) media. PDS.H, which had the highest digestion resistibility, exhibited significant effects on the OD600 nm value (1.544) and the pH value (4.21) when the carbohydrate concentration was 20 g L-1. Additionally, the exponential growth phase of bifidobacteria was 2 h in the PDS or PDS.H media, whereas it was 4 h in the GLU or DAS media. A higher content of short-chain fatty acids (SCFAs) was obtained in the PDS.H medium. Analysis of the structural features of RS and fermented RS indicated that PDS, especially PDS.H, had a rougher surface and higher crystallinity than DAS. Fermented RS in a simulated large bowel environment showed an eroded surface and decreased crystallinity. All of these findings suggest that RS with a rough surface and perfect crystalline structure could protect bifidobacteria from gastrointestinal conditions and enhance the proliferation of bifidobacteria.


Assuntos
Bifidobacterium adolescentis/crescimento & desenvolvimento , Bifidobacterium adolescentis/metabolismo , Extratos Vegetais/metabolismo , Prebióticos/análise , Amido/metabolismo , Dioscorea/química , Dioscorea/metabolismo , Dioscorea/microbiologia , Ácidos Graxos Voláteis/metabolismo , Fermentação , Intestino Grosso/metabolismo , Intestino Grosso/microbiologia , Tubérculos/química , Tubérculos/metabolismo , Tubérculos/microbiologia , Amido/química
10.
Oxid Med Cell Longev ; 2017: 4176518, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29085554

RESUMO

Studying the biotransformation of natural products by intestinal microflora is an important approach to understanding how and why some medicines-particularly natural medicines-work. In many cases, the active components are generated by metabolic activation. This is critical for drug research and development. As a means to explore the therapeutic mechanism of Dioscorea nipponica (DN), a medicinal plant used to treat myocardial ischemia (MI), metabolites generated by intestinal microflora from DN were identified, and the cardioprotective efficacy of these metabolites was evaluated. Our results demonstrate that diosgenin is the main metabolite produced by rat intestinal microflora from DN. Further, our results show that diosgenin protects the myocardium against ischemic insult through increasing enzymatic and nonenzymatic antioxidant levels in vivo and by decreasing oxidative stress damage. These mechanisms explain the clinical efficacy of DN as an anti-MI drug.


Assuntos
Biotransformação/imunologia , Cardiotônicos/uso terapêutico , Dioscorea/metabolismo , Diosgenina/uso terapêutico , Plantas Medicinais/metabolismo , Animais , Cardiotônicos/farmacologia , Diosgenina/farmacologia , Microbioma Gastrointestinal/efeitos dos fármacos , Humanos , Masculino , Ratos , Ratos Sprague-Dawley
11.
Sci Rep ; 6: 29136, 2016 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-27385275

RESUMO

Yams (Dioscorea spp.) are a multispecies crop with production in over 50 countries generating ~50 MT of edible tubers annually. The long-term storage potential of these tubers is vital for food security in developing countries. Furthermore, many species are important sources of pharmaceutical precursors. Despite these attributes as staple food crops and sources of high-value chemicals, Dioscorea spp. remain largely neglected in comparison to other staple tuber crops of tropical agricultural systems such as cassava (Manihot esculenta) and sweet potato (Ipomoea batatas). To date, studies have focussed on the tubers or rhizomes of Dioscorea, neglecting the foliage as waste. In the present study metabolite profiling procedures, using GC-MS approaches, have been established to assess biochemical diversity across species. The robustness of the procedures was shown using material from the phylogenetic clades. The resultant data allowed separation of the genotypes into clades, species and morphological traits with a putative geographical origin. Additionally, we show the potential of foliage material as a renewable source of high-value compounds.


Assuntos
Biodiversidade , Dioscorea/metabolismo , Metabolômica/métodos , Compostos Fitoquímicos/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Geografia , Metaboloma , Filogenia , Extratos Vegetais/metabolismo , Folhas de Planta/metabolismo , Ácido Chiquímico/metabolismo , Especificidade da Espécie
12.
Appl Biochem Biotechnol ; 180(1): 79-93, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27131879

RESUMO

Rhizomes of Dioscorea species are traditionally used for relieving menopausal syndromes in Chinese medicine. The estrogen-stimulating bioactive principles have been demonstrated in our previous study. In this study, the estrogen-stimulating effects of proteins isolated from four Dioscorea species [D. alata L. (DA), D. zingiberensis C.H. Wright (DH), D. collettii var. hypoglauca (Palib.) S.J. Pei & C.T. Ting (DH), and D. oppositifolia L. (DO)] have been investigated and compared. Microscopic authentication of four Dioscorea species was performed by using paraffin and powder sections of the rhizomes. The potential bioactive proteins of four Dioscorea species have been rapidly isolated by using a DOI-antibody affinity column chromatography on immobilized antibodies against on estradiol-stimulating protein from DO (DOI), and their bioactivity has been rapidly confirmed and compared by phenotypic (i.e., estradiol-stimulating effect) and target-based (i.e., STAR, aromatase, estrogen receptors) screening approaches. The estrogen-stimulating activity of bioactive proteins from DO is the highest. In addition, bioactive proteins from DO upregulated the estradiol-metabolizing enzymes (aromatase and steroidogenic acute regulatory protein). Meanwhile, bioactive proteins from DA, DH and DO upregulated estrogen receptor ß (ERß). All bioactive proteins did not change the expression of estrogen receptor ß (ERα). The estrogen-stimulating bioactive proteins isolated from DO increased biosynthesis of estradiol and upregulated the protein expression of aromatase, steroidogenic acute regulatory protein, and ERß. The results scientifically support the traditional use of DO in Chinese medicine for relieving menopausal syndrome. Besides, proteins from DA and DZ could also upregulate the translational levels of ERß, and potentially reducing the risk of ovarian cancer, which also support the clinical use of them for treating female aging disorder. Graphical Abstract Comparative Analysis of DOI-like Proteins with Stimulating Activity on Ovarian Estradiol Biosynthesis from Four Different Dioscorea Species in vitro.


Assuntos
Dioscorea/metabolismo , Estradiol/biossíntese , Menopausa/efeitos dos fármacos , Menopausa/fisiologia , Ovário/metabolismo , Proteínas de Plantas/farmacologia , Animais , Aromatase/metabolismo , Western Blotting , Eletroforese em Gel de Poliacrilamida , Feminino , Células da Granulosa/citologia , Células da Granulosa/efeitos dos fármacos , Células da Granulosa/metabolismo , Humanos , Ovário/citologia , Ovário/efeitos dos fármacos , Inclusão em Parafina , Fenótipo , Fosfoproteínas/metabolismo , Pós , Ratos Sprague-Dawley , Receptores de Estrogênio/metabolismo , Rizoma/química
13.
Sci Rep ; 5: 10179, 2015 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-26160710

RESUMO

A novel protein, designated as DOI, isolated from the Chinese yam (Dioscorea opposita Thunb.) could be the first protein drug for the treatment of menopausal syndrome and an alternative to hormone replacement therapy (HRT), which is known to have undesirable side effects. DOI is an acid- and thermo-stable protein with a distinctive N-terminal sequence Gly-Ile-Gly-Lys-Ile-Thr-Thr-Tyr-Trp-Gly-Gln-Tyr-Ser-Asp-Glu-Pro-Ser-Leu-Thr-Glu. DOI was found to stimulate estradiol biosynthesis in rat ovarian granulosa cells; induce estradiol and progesterone secretion in 16- to 18-month-old female Sprague Dawley rats by upregulating expressions of follicle-stimulating hormone receptor and ovarian aromatase; counteract the progression of osteoporosis and augment bone mineral density; and improve cognitive functioning by upregulating protein expressions of brain-derived neurotrophic factor and TrkB receptors in the prefrontal cortex. Furthermore, DOI did not stimulate the proliferation of breast cancer and ovarian cancer cells, which suggest it could be a more efficacious and safer alternative to HRT.


Assuntos
Dioscorea/metabolismo , Estradiol/biossíntese , Proteínas de Plantas/metabolismo , Sequência de Aminoácidos , Animais , Aromatase/genética , Aromatase/metabolismo , Densidade Óssea , Osso e Ossos/diagnóstico por imagem , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Feminino , Menopausa , Dados de Sequência Molecular , Osteoporose/prevenção & controle , Ovário/citologia , Peptídeos/química , Peptídeos/uso terapêutico , Proteínas de Plantas/química , Córtex Pré-Frontal/metabolismo , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Receptor trkB/metabolismo , Receptores do FSH/genética , Receptores do FSH/metabolismo , Rizoma/metabolismo , Microtomografia por Raio-X
14.
Electron. j. biotechnol ; 16(5): 6-6, Sept. 2013. ilus, tab
Artigo em Inglês | LILACS | ID: lil-690466

RESUMO

Background: The perennial medicinal herb Dioscorea zingiberensis is a very important plant used for steroid drug manufacturing for its high level of diosgenin in rhizome. Although the stimulation of diosgenin accumulation by ethylene has been reported in a few of plant species, its regulation is not yet characterized at the molecular level, the underlying molecular mechanism remains elusive. Results: In this study, the effects of ethylene on diosgenin biosynthesis in in vitro cultures of D. zingiberensis were described. The results showed that, in samples treated with ethylene at concentration E3 (10(4) dilution of 40% ethephon), the diosgenin biosynthesis was significantly promoted in comparison with the control samples. Treatment with high concentrations of ethylene had inhibitory effect, whereas with low concentration of the gas elicitor brought about no detectable deleterious effect on the growth rate and diosgenin content of the cultures. The considerable increase of diosgenin level in in vitro cultured Dioscorea zingiberensis by ethylene application is accompanied by the concomitant increase of soluble proteins and chlorophyll content. The gene expressions of cycloartenol synthase and 3-hydroxy-3-methylglutaryl-CoA reductase but not of squalene synthase or farnesyl pyrophosphate synthase were up-regulated by applied ethylene. Conclusions: Our results suggest that ethylene treatment enhanced diosgenin accumulation via up-regulation of the gene expressions of cycloartenol synthase and 3-hydroxy-3-methylglutaryl-CoA reductase.


Assuntos
Transferases Intramoleculares/genética , Transferases Intramoleculares/metabolismo , Dioscorea/metabolismo , Hidroximetilglutaril-CoA Redutases/genética , Hidroximetilglutaril-CoA Redutases/metabolismo , Técnicas In Vitro , RNA/isolamento & purificação , Expressão Gênica , Regulação para Cima , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Dioscorea/crescimento & desenvolvimento , Dioscorea/genética , Diosgenina/análise , Etilenos
15.
Bioresour Technol ; 146: 549-555, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23973974

RESUMO

A novel method utilizing microbial treatment for cleaner production of diosgenin from Dioscorea zingiberensis C.H. Wright (DZW) was presented. A new Bacillus pumilus HR19, which has the great ability to secrete pectinase, was screened and applied in the microbial treatment. Low-pressure steam expansion pretreatment (LSEP) was employed in advance to assist microbial treatment efficiently in releasing saponins, which are the precursors of diosgenin. Compared with the traditional process of acid hydrolysis, this novel process reduced the consumptions of water, acid and organic solvent by more than 92.5%, 97.0%, 97.0%, respectively, while simultaneously increasing the diosgenin yield by 6.21%. In addition, the microbial treatment was more efficient than enzymatic treatment, which arised from that microorganisms could be induced to secrete related enzymes by the compositions of DZW and relieve product inhibition by utilizing enzyme hydrolysates.


Assuntos
Bacillus/metabolismo , Dioscorea/metabolismo , Diosgenina/metabolismo , Poligalacturonase/metabolismo , Parede Celular/metabolismo , Poluentes Ambientais/análise , Enzimas/química , Hidrólise , Indústrias , Lignina/química , Pressão , Saponinas/química , Solventes/química , Vapor , Temperatura , Águas Residuárias , Água/química , Poluentes Químicos da Água/análise
16.
Biochim Biophys Acta ; 1828(3): 1153-8, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23262192

RESUMO

Dioscin is a kind of steroidal saponin isolated from the root bark of wild yam Dioscorea nipponica. We investigated the antifungal effect of dioscin against different fungal strains and its antifungal mechanism(s) in Candida albicans cells. Using the propidium iodide assay and calcein-leakage measurement, we confirmed that dioscin caused fungal membrane damage. Furthermore, we evaluated the ability of dioscin to disrupt the plasma membrane potential, using 3,3'-dipropylthiadicarbocyanine iodide [DiSC(3)(5)] and bis-(1,3-dibarbituric acid)-trimethine oxanol [DiBAC(4)(3)]. Cells stained with the dyes had a significant increase in fluorescent intensity after exposure to dioscin, indicating that dioscin has an effect on the membrane potential. To visualize the effect of dioscin on the cell membrane, we synthesized rhodamine-labeled giant unilamellar vesicles (GUVs) mimicking the outer leaflet of the plasma membrane of C. albicans. As seen in the result, the membrane disruptive action of dioscin caused morphological change and rhodamine leakage of the GUVs. In three-dimensional contour-plot analysis using flow cytometry, we observed a decrease in cell size, which is in agreement with our result from the GUV assay. These results suggest that dioscin exerts a considerable antifungal activity by disrupting the structure in membrane after invading into the fungal membrane, resulting in fungal cell death.


Assuntos
Antifúngicos/farmacologia , Candida albicans/efeitos dos fármacos , Dioscorea/metabolismo , Diosgenina/análogos & derivados , Biofísica/métodos , Membrana Celular/efeitos dos fármacos , Diosgenina/química , Relação Dose-Resposta a Droga , Citometria de Fluxo/métodos , Fluoresceínas/química , Potenciais da Membrana/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Microscopia de Fluorescência/métodos , Extratos Vegetais/metabolismo , Propídio/farmacologia , Rodaminas/farmacologia , Fatores de Tempo
17.
Food Chem ; 134(2): 1074-80, 2012 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-23107730

RESUMO

A study was undertaken to evaluate whether the interaction between Monascus-fermented products and lovastatin contributes to increased risk of rhabdomyolysis. Rhabdomyolysis is a potentially dangerous side effect of statin drugs. In this study with hyperlipidemic hamsters fed lovastatin only, lovastatin with 1-fold red mold dioscorea (RMD), and lovastatin, the functional components of red mold fermented products, HMG-CoA reductase inhibitors, did not exacerbate pre-existing diseases, and actually helped in improving existing disease conditions, respectively, as compared with the control. Administration of RMD, alone or in combination with lovastatin did not cause significant rhabdomyolysis as assessed by measuring the levels of creatinine phosphokinase. Further, we did not find any study that clearly implicates the involvement of RMD, which have long been considered a food product, in liver and kidney toxicity. RMD alone or in combination with lovastatin, does not increase the risk of rhabdomyolysis, even when administered at a high dosage (including HMG-CoA reductase inhibitors >75 mg/day/adult).


Assuntos
Dioscorea/microbiologia , Alimento Funcional/microbiologia , Hiperlipidemias/dietoterapia , Hipolipemiantes/metabolismo , Monascus/metabolismo , Animais , Colesterol/metabolismo , Terapia Combinada , Cricetinae , Dioscorea/efeitos adversos , Dioscorea/metabolismo , Fermentação , Alimento Funcional/efeitos adversos , Alimento Funcional/análise , Humanos , Hiperlipidemias/complicações , Hiperlipidemias/tratamento farmacológico , Hiperlipidemias/metabolismo , Hipolipemiantes/efeitos adversos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Lovastatina/administração & dosagem , Masculino , Mesocricetus , Rabdomiólise/etiologia , Triglicerídeos/metabolismo
18.
J Sci Food Agric ; 92(7): 1483-9, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22144071

RESUMO

BACKGROUND: Monascus-fermented products have featured in Chinese cuisine for thousands of years and are widely used as food colourants and dietary materials in many Asian countries. Rice and dioscorea fermented with Monascus purpureus NTU 568 have health-promoting attributes in vitro and in vivo. The aim of this study was to investigate the immunomodulatory and antioxidant effects of polysaccharides from red mould rice (RMRP) and red mould dioscorea (RMDP) in Raw 264.7 cells. RESULTS: The results showed the antioxidant capabilities (including scavenging, chelating, inhibition of lipid peroxidation, and reducing power) of RMRP and RMDP at a concentration of 10 mg mL(-1). RMRP and RMDP also stimulated cell proliferation, nitric oxide production, phagocytosis and cytokine production (including IL1-ß, IL-6 and TNF-α) in Raw 264.7 cells. CONCLUSION: These findings demonstrate that RMRP and RMDP have antioxidant and immunomodulation potential to be developed as novel dietary supplements.


Assuntos
Antioxidantes/farmacologia , Dioscorea/química , Fatores Imunológicos/farmacologia , Monascus/metabolismo , Oryza/química , Preparações de Plantas/farmacologia , Polissacarídeos/farmacologia , Animais , Proliferação de Células/efeitos dos fármacos , Citocinas/biossíntese , Suplementos Nutricionais , Dioscorea/metabolismo , Fermentação , Macrófagos/efeitos dos fármacos , Camundongos , Oryza/metabolismo , Fagocitose/efeitos dos fármacos
19.
Molecules ; 16(11): 9003-16, 2011 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-22031064

RESUMO

Three polysaccharides, namely exopolysaccharide (EPS), water-extracted mycelial polysaccharide (WPS) and sodium hydroxide-extracted mycelial polysaccharide (SPS), were prepared from the endophytic fungus Fusarium oxysporium Dzf17 isolated from the rhizomes of Dioscorea zingiberensis. The effects of the time of addition and polysaccharide concentration on the growth and diosgenin accumulation in cell suspension culture of D. zingiberensis were studied. Among them, WPS was found to be the most effective polysaccharide. When WPS was added to the medium at 20 mg/L on the 25th day of culture, the cell dry weight was increased 1.34-fold, diosgenin content 2.85-fold, and diosgenin yield 3.83-fold in comparison to those of control. EPS and SPS showed moderate and relatively weak enhancement effects on cell growth and diosgenin accumulation, respectively. The dynamics of cell growth and diosgenin accumulation when WPS was added to the medium at 20 mg/L on the 25th day of culture were investigated, and results showed that dry weight of cells reached a maximum value on day 30 but the maximum diosgenin content was achieved on day 31.


Assuntos
Dioscorea/efeitos dos fármacos , Dioscorea/metabolismo , Dioscorea/microbiologia , Diosgenina/metabolismo , Endófitos/química , Fusarium/química , Polissacarídeos/farmacologia , Células Cultivadas , Dioscorea/citologia , Medicina Tradicional Chinesa , Rizoma/microbiologia
20.
J Agric Food Chem ; 59(15): 8199-207, 2011 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-21732592

RESUMO

Red mold dioscorea (RMD) produced by Monascus sp. was proven to be a hypolipidemic functional food. Deep ocean water (DOW), that is, water obtained from over 200 m deep in the ocean, was found to promote the growth of fungus via its mineral richness. On the basis of the advantages, this study used 650 m DOW as the culture water to culture Monascus purpuresus NTU 568 and produce the DOW-RMD. The goal of this study is to compare the difference between DOW-RMD and reverse osmosis water-cultured RMD (ROW-RMD) on the hypolipidemic effect. Hyperlipidemic hamsters were fed a high-cholesterol diet and administered various doses of DOW-RMD or ROW-RMD for 8 weeks. After sacrifice, biochemical analyses in serum, liver, and feces were carried out. The results showed that DOW-RMD had a greater effect on lowering cholesterol levels and lipid peroxidation in serum and lipid plaque in heart aorta than ROW-RMD. However, DOW was likely to modulate the Monascus metabolite biosynthesis pathway toward the formation of hypolipidemic yellow pigments (such as monascin and ankaflavin) rather than red pigments and the mycotoxin citrinin. In addition, the DOW with higher Mg(2+) ion was proven to absorb into DOW-RMD; however, the accumulation of Mg(2+) ions should contribute a greater hypolipidemic effect to DOW-RMD. Comprehensively, the DOW-induced metabolism modulation and the ions of DOW were a benefit to the development of safe DOW-RMD with low citrinin levels and high hypolipidemic, antiatherosclerosis, and anti-fatty liver effects.


Assuntos
Dioscorea/microbiologia , Hiperlipidemias/tratamento farmacológico , Hipolipemiantes/metabolismo , Monascus/metabolismo , Preparações de Plantas/metabolismo , Animais , Cricetinae , Meios de Cultura/análise , Meios de Cultura/metabolismo , Dioscorea/metabolismo , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Fermentação , Humanos , Hiperlipidemias/metabolismo , Hipolipemiantes/administração & dosagem , Hipolipemiantes/efeitos adversos , Masculino , Mesocricetus , Monascus/crescimento & desenvolvimento , Preparações de Plantas/administração & dosagem , Preparações de Plantas/efeitos adversos , Água do Mar/análise , Água do Mar/microbiologia
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