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1.
J Agric Food Chem ; 68(1): 206-212, 2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31808686

RESUMO

The present study aimed to investigate the effects of matured hop bitter acids (MHBAs) on human cognition, mental fatigue, and mood state. In this randomized double-blind placebo-controlled study, 60 healthy adults (age 45-64 years) with self-awareness of cognitive decline were randomly divided into 2 groups and received either orally administered MHBAs (35 mg/day) or placebo for 12 weeks. Cognitive functions and mental states were assessed using neuropsychological tests or questionnaires at baseline and weeks 6 and 12 of the intervention. The change in verbal fluency score at week 6 compared with that at baseline was significantly higher in the MHBAs-treated group compared with that in the placebo group (P = 0.034), and Stroop test score at week 12 was significantly lower in the MHBAs-treated group compared with the placebo group (P = 0.019). Furthermore, subjective fatigue and anxiety at week 12 were significantly improved in the MHBAs-treated group (P = 0.008 and 0.043, respectively) compared with the placebo group. This is the first study to evaluate the effects of bitter ingredients in beer on cognition, subjective mood, and mental fatigue in a clinical trial. Our findings suggest that hop-derived bitter acids might be beneficial for cognition and mood state.


Assuntos
Ácidos/metabolismo , Cerveja/análise , Cognição , Disfunção Cognitiva/metabolismo , Disfunção Cognitiva/psicologia , Humulus/química , Humulus/metabolismo , Extratos Vegetais/metabolismo , Ácidos/análise , Afeto , Feminino , Voluntários Saudáveis , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos
2.
J Agric Food Chem ; 67(42): 11650-11656, 2019 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-31554401

RESUMO

Occurring in hops (Humulus lupulus) and beer as a racemic mixture, (2R,2S)-8-prenylnaringenin (8-PN) is a potent phytoestrogen in hop dietary supplements used by women as alternatives to conventional hormone therapy. With a half-life exceeding 20 h, 8-PN is excreted primarily as 8-PN-7-O-glucuronide or 8-PN-4'-O-glucuronide. Human liver microsomes and 11 recombinant human UDP-glucuronosyltransferases (UGTs) were used to catalyze the formation of the two oxygen-linked glucuronides of purified (2R)-8-PN and (2S)-8-PN, which were subsequently identified using mass spectrometry and nuclear magnetic resonance spectroscopy. Formation of (2R)- and (2S)-8-PN-7-O-glucuronides predominated over the 8-PN-4'-O-glucuronides except for intestinal UGT1A10, which formed more (2S)-8-PN-4'-O-glucuronide. (2R)-8-PN was a better substrate for all 11 UGTs except for UGT1A1, which formed more of both (2S)-8-PN glucuronides than (2R)-8-PN glucuronides. Although several UGTs conjugated both enantiomers of 8-PN, some conjugated just one enantiomer, suggesting that human phenotypic variation might affect the routes of metabolism of this chiral estrogenic constituent of hops.


Assuntos
Flavanonas/química , Glucuronídeos/química , Glucuronosiltransferase/química , Extratos Vegetais/química , Biocatálise , Flavanonas/metabolismo , Glucuronídeos/metabolismo , Glucuronosiltransferase/metabolismo , Humanos , Humulus/química , Humulus/metabolismo , Espectrometria de Massas , Microssomos Hepáticos/química , Microssomos Hepáticos/metabolismo , Extratos Vegetais/metabolismo , Estereoisomerismo
3.
J Agric Food Chem ; 67(30): 8291-8302, 2019 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-31287692

RESUMO

Over the next 50 years, the prevention and control of chronic diseases, such as obesity, cardiovascular disease, Alzheimer's disease, and many cancers, will be one of the most critical challenges in human health. Plant biochemistry and phytonutrient supplements are a promising complementary therapy for the management of chronic disease. Among them, Humulus lupulus has attracted special attention throughout the world because it contains numerous dietary phytochemicals that not only contribute to the aroma and flavor of beer but may also be used for medicinal purposes, as its properties include antiseptic, (an)aphrodisiac, anticancer, antiplatelet, antibacterial, antidiuretic, anti-inflammatory, sedative, hypnotic, and stomachic properties. This review sought to identify and understand the risk factors for chronic disease with a focus on two types of phytochemicals, bitter acids and xanthohumol. The goal was to understand how their metabolites promote human health and reduce the risk of chronic disease.


Assuntos
Humulus/metabolismo , Extratos Vegetais/química , Extratos Vegetais/metabolismo , Animais , Saúde , Humanos , Humulus/química
4.
Food Chem ; 275: 15-23, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30724181

RESUMO

This study investigated the volatile phytochemical diversity of 30 samples obtained from experimental hybrid and commercial H. lupulus L. plants. Essential oils distilled from these samples were analysed by high resolution gas chromatography coupled with accurate mass time-of-flight mass spectrometry (GC-accTOFMS). A total of 58 secondary metabolites, mainly comprising 18 esters, 6 monoterpene hydrocarbons, 2 oxygenated monoterpenes, 20 sesquiterpene hydrocarbons, 7 oxygenated sesquiterpenes, and 4 ketones, were positively or tentatively identified. A total of 24 metabolites were detected in all samples, but commercial cultivars (selected for brewing performance) had fewer compounds identified compared to experimental genotypes. Chemometrics analyses enabled distinct differentiation of experimental hybrids from commercial cultivars, discussed in terms of the different classes of compounds present in different genotypes. Differences among the mono- and sesquiterpenoids, appear to be related to either: i) the genetic origin of the plants; or ii) the processes of bioaccumulation of the identified secondary metabolites.


Assuntos
Humulus/química , Óleos Voláteis/análise , Austrália , Cerveja , Cromatografia Gasosa-Espectrometria de Massas/métodos , Genótipo , Humulus/genética , Humulus/metabolismo , Monoterpenos/análise , Óleos Voláteis/química , Compostos Fitoquímicos/análise , Metabolismo Secundário , Sesquiterpenos/análise
5.
Appl Biochem Biotechnol ; 188(3): 787-797, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30684240

RESUMO

Lupulones, naturally produced by glandular trichomes of hop (Humulus lupulus), are prenylated phloroglucinol derivatives that contribute the bitter flavor of beer and demonstrate antimicrobial and anticancer activities. It is appealing to develop microbial cell factories such that lupulones may be produced via fermentation technology in lieu of extraction from limited plant resources. In this study, the yeast Saccharomyces cerevisiae transformants harboring a synthetic lupulone pathway that consisted of five genes from hop were constructed. The transformants accumulated several precursors but failed to accumulate lupulones. Overexpression of 3-hydroxy-3-methyl glutaryl co-enzyme A reductase, the key enzyme in precursor formation in the mevalonate pathway, also failed to achieve a detectable level of lupulones. To decrease the consumption of the precursors, the ergosterol biosynthesis pathway was chemically downregulated by a small molecule ketoconazole, leading to successful production of lupulones. Our study demonstrated a combination of molecular biology and chemical biology to regulate the metabolism for heterologous production of lupulones. The strategy may be valuable for future engineering microbial process for other prenylated natural products.


Assuntos
Saccharomyces cerevisiae/genética , Terpenos/metabolismo , Genes de Plantas , Humulus/efeitos dos fármacos , Humulus/genética , Humulus/metabolismo , Hidroximetilglutaril-CoA Redutases/metabolismo , Cetoconazol/farmacologia , Ácido Mevalônico/metabolismo
6.
Chem Res Toxicol ; 32(2): 222-233, 2019 02 18.
Artigo em Inglês | MEDLINE | ID: mdl-30608650

RESUMO

Botanical dietary supplements for women's health are increasingly popular. Older women tend to take botanical supplements such as hops as natural alternatives to traditional hormone therapy to relieve menopausal symptoms. Especially extracts from spent hops, the plant material remaining after beer brewing, are enriched in bioactive prenylated flavonoids that correlate with the health benefits of the plant. The chalcone xanthohumol (XH) is the major prenylated flavonoid in spent hops. Other less abundant but important bioactive prenylated flavonoids are isoxanthohumol (IX), 8-prenylnaringenin (8-PN), and 6-prenylnaringenin (6-PN). Pharmacokinetic studies revealed that these flavonoids are conjugated rapidly with glucuronic acid. XH also undergoes phase I metabolism in vivo to form IX, 8-PN, and 6-PN. Several hop constituents are responsible for distinct effects linked to multiple biological targets, including hormonal, metabolic, inflammatory, and epigenetic pathways. 8-PN is one of the most potent phytoestrogens and is responsible for hops' estrogenic activities. Hops also inhibit aromatase activity, which is linked to 8-PN. The weak electrophile, XH, can activate the Keap1-Nrf2 pathway and turn on the synthesis of detoxification enzymes such as NAD(P)H-quinone oxidoreductase 1 and glutathione S-transferase. XH also alkylates IKK and NF-κB, resulting in anti-inflammatory activity. Antiobesity activities have been described for XH and XH-rich hop extracts likely through activation of AMP-activated protein kinase signaling pathways. Hop extracts modulate the estrogen chemical carcinogenesis pathway by enhancing P450 1A1 detoxification. The mechanism appears to involve activation of the aryl hydrocarbon receptor (AhR) by the AhR agonist, 6-PN, leading to degradation of the estrogen receptor. Finally, prenylated phenols from hops are known inhibitors of P450 1A1/2; P450 1B1; and P450 2C8, 2C9, and 2C19. Understanding the biological targets of hop dietary supplements and their phytoconstituents will ultimately lead to standardized botanical products with higher efficacy, safety, and chemopreventive properties.


Assuntos
Flavonoides/química , Humulus/química , Proteínas Quinases Ativadas por AMP/metabolismo , Citocromo P-450 CYP1A1/metabolismo , Feminino , Flavonoides/metabolismo , Flavonoides/farmacologia , Humanos , Humulus/metabolismo , Extratos Vegetais/química , Receptores de Hidrocarboneto Arílico/química , Receptores de Hidrocarboneto Arílico/metabolismo , Receptores Estrogênicos/química , Receptores Estrogênicos/metabolismo , Transdução de Sinais/efeitos dos fármacos
7.
J Sci Food Agric ; 99(4): 1772-1779, 2019 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-30226273

RESUMO

BACKGROUND: Although fatty acids have a beneficial effect on yeast growth during fermentation, their effect on foam and sensory stability of beer is negative. In general, long-chain fatty acids originate from raw materials, whereas short-chain acids are produced by yeast during fermentation. If the concentration of short-chain fatty acids, especially isovaleric and butyric acid, overreaches a sensory threshold, then an unpleasant aroma, such as cheesy or sweaty feet, can be formed in beer. RESULTS: The distribution of fatty acids, from the preparation of sweet wort to the final beer, was studied using chemometric evaluation. Differences were observed between the decoction and infusion system using four barley varieties. Attention was paid to the behavior of short-chain fatty acids, namely isovaleric acid. The concentration of isovaleric acid in commercial beers brewed in infusion and decoction systems was approximately 1.4 and 1.0 mg L-1 , respectively. The same trend was observed in experimental samples (1.3 and 0.5 mg L-1 , respectively). This phenomenon was confirmed experimentally; based on the results, this possibly explains why, during the fermentation, isovaleric acid is coupled with the redox state of yeast cell, which is given by the wort composition (i.e. by the mashing process). CONCLUSION: The formation of isovaleric acid is not only caused by microbiology infection or by oxidized hops, but also is influenced by the mashing process. © 2018 Society of Chemical Industry.


Assuntos
Cerveja/análise , Ácidos Graxos/química , Hordeum/química , Ácidos Graxos/metabolismo , Fermentação , Manipulação de Alimentos , Hordeum/metabolismo , Humanos , Humulus/química , Humulus/metabolismo , Oxirredução , Saccharomyces cerevisiae/metabolismo , Paladar
8.
FEMS Microbiol Rev ; 43(3): 193-222, 2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-30445501

RESUMO

Aroma compounds provide attractiveness and variety to alcoholic beverages. We discuss the molecular biology of a major subset of beer aroma volatiles, fruity and floral compounds, originating from raw materials (malt and hops), or formed by yeast during fermentation. We introduce aroma perception, describe the most aroma-active, fruity and floral compounds in fruits and their presence and origin in beer. They are classified into categories based on their functional groups and biosynthesis pathways: (1) higher alcohols and esters, (2) polyfunctional thiols, (3) lactones and furanones, and (4) terpenoids. Yeast and hops are the main sources of fruity and flowery aroma compounds in beer. For yeast, the focus is on higher alcohols and esters, and particularly the complex regulation of the alcohol acetyl transferase ATF1 gene. We discuss the release of polyfunctional thiols and monoterpenoids from cysteine- and glutathione-S-conjugated compounds and glucosides, respectively, the primary biological functions of the yeast enzymes involved, their mode of action and mechanisms of regulation that control aroma compound production. Furthermore, we discuss biochemistry and genetics of terpenoid production and formation of non-volatile precursors in Humulus lupulus (hops). Insight in these pathways provides a toolbox for creating innovative products with a diversity of pleasant aromas.


Assuntos
Bebidas Alcoólicas/análise , Cerveja/análise , Microbiologia de Alimentos , Odorantes/análise , Compostos Orgânicos Voláteis/análise , Humulus/genética , Humulus/metabolismo , Proteínas/genética , Proteínas/metabolismo , Saccharomyces cerevisiae/enzimologia , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo
9.
Food Chem ; 277: 32-37, 2019 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-30502152

RESUMO

For brewers, it is important to know the geographic origins of the hop plants (Humulus lupulus L.) used in their brewing processes since the contents and compositions of the bitter resins and essential oils in them depend on the environmental conditions during their growth. In this study, the multi-elemental profiles of hop plants from each of the world's main growing regions were determined by non-destructive energy dispersive X-ray fluorescence spectrometry (EDXRF). Understanding the multi-element profiles of the plants could be a useful tool in determining the geographic origins of produced hop plants.


Assuntos
Humulus/química , Óleos Voláteis/química , Resinas Vegetais/química , Austrália , Análise Discriminante , Humulus/metabolismo , Nova Zelândia , Óleos Voláteis/análise , Análise de Componente Principal , Resinas Vegetais/análise , África do Sul , Espectrometria por Raios X , Estados Unidos
10.
J Agric Food Chem ; 67(1): 364-371, 2019 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-30539627

RESUMO

Bottom-fermented and top-fermented beers, both either late or dry hopped with Huell Melon hops, and respective reference beers without late or dry hopping were subjected to a comparative odorant screening by aroma extract dilution analyses. On the basis of differences in the FD factors, 14 odorants were identified as hop-derived. Among them were ethyl 2-methylpropanoate, methyl 2-methylbutanoate, ethyl 2-methylbutanoate, propyl 2-methylbutanoate, myrcene, linalool, and geraniol. Differences between late hopped, dry hopped, and reference beers were substantiated by quantitation. Results showed minimal transfer of myrcene from hops into beer. Moderate transfer was observed for propyl 2-methylbutanoate, geraniol, and linalool. Process-induced changes of ethyl 2-methylpropanoate, ethyl 2-methylbutanoate, and methyl 2-methylbutanoate were beyond a direct transfer from hops into beer, suggesting a formation from the corresponding hop-derived carboxylic acids by yeast. Spiking experiments revealed that linalool and propyl 2-methylbutanoate contributed particularly to the characteristic aroma of beers flavored with Huell Melon hops.


Assuntos
Cerveja/análise , Aromatizantes/metabolismo , Humulus/metabolismo , Leveduras/metabolismo , Adulto , Feminino , Fermentação , Aromatizantes/química , Frutas/química , Frutas/classificação , Frutas/metabolismo , Frutas/microbiologia , Humanos , Humulus/química , Humulus/classificação , Humulus/microbiologia , Masculino , Pessoa de Meia-Idade , Odorantes/análise , Paladar , Adulto Jovem
11.
Cell Physiol Biochem ; 51(2): 543-556, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30458450

RESUMO

BACKGROUND/AIMS: Prenylnaringenins are natural prenylflavonoids with anticancer properties. However, the underlying mechanisms have not been elucidated yet. Here we report a novel mode of action of 6- and 8-prenylnaringenin (PN) on human melanoma cells: Inhibition of cellular histone deacetylases (HDACs). METHODS: We performed in silico and in vitro analyses using 6-PN or 8-PN to study a possible interaction of 6-PN or 8-PN with HDAC as well as Western blot and FACS analyses, real-time cell proliferation and cell viability assays to assess the impact of 6-PN and 8-PN on human metastatic melanoma cells. RESULTS: In silico, 6-PN and 8-PN fit into the binding pocket of HDAC2, 4, 7 and 8, binding to the zinc ion of their catalytic center that is essential for enzymatic activity. In vitro, 100 µmol/L of 6-PN or 8-PN inhibited all 11 conserved human HDAC of class I, II and IV. In clinical oncology HDAC inhibitors are currently investigated as new anticancer compounds. In line, treatment of SK-MEL-28 cells with 6-PN or 8-PN induced a hyperacetylation of histone complex H3 within 2 h. Further, 6-PN or 8-PN mediated a prominent, dose-dependent reduction of cellular proliferation and viability of SK-MEL-28 and BLM melanoma cells. This effect was apoptosis-independent and accompanied by down-regulation of mTOR-specific pS6 protein via pERK/pP90 in SK-MEL-28 cells. CONCLUSION: The identification of a broad inhibitory capacity of 6-PN and 8-PN for HDAC enzymes with antiproliferative effects on melanoma cells opens the perspective for clinical application as novel anti-melanoma drugs and the usage as innovative lead structures for chemical modification to enhance pharmacology or inhibitory activities.


Assuntos
Apoptose/efeitos dos fármacos , Flavanonas/farmacologia , Flavonoides/farmacologia , Inibidores de Histona Desacetilases/farmacologia , Humulus/química , Acetilação/efeitos dos fármacos , Sítios de Ligação , Domínio Catalítico , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Regulação para Baixo/efeitos dos fármacos , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Flavanonas/química , Flavanonas/isolamento & purificação , Flavonoides/química , Flavonoides/isolamento & purificação , Inibidores de Histona Desacetilases/química , Inibidores de Histona Desacetilases/isolamento & purificação , Histona Desacetilases/química , Histona Desacetilases/metabolismo , Histonas/metabolismo , Humanos , Humulus/metabolismo , Melanoma/metabolismo , Melanoma/patologia , Simulação de Acoplamento Molecular , Isoformas de Proteínas/antagonistas & inibidores , Isoformas de Proteínas/metabolismo , Proteínas Quinases S6 Ribossômicas/genética , Proteínas Quinases S6 Ribossômicas/metabolismo , Serina-Treonina Quinases TOR/metabolismo
12.
Viruses ; 10(10)2018 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-30340328

RESUMO

Viroids are smallest known pathogen that consist of non-capsidated, single-stranded non-coding RNA replicons and they exploits host factors for their replication and propagation. The severe stunting disease caused by Citrus bark cracking viroid (CBCVd) is a serious threat, which spreads rapidly within hop gardens. In this study, we employed comprehensive transcriptome analyses to dissect host-viroid interactions and identify gene expression changes that are associated with disease development in hop. Our analysis revealed that CBCVd-infection resulted in the massive modulation of activity of over 2000 genes. Expression of genes associated with plant immune responses (protein kinase and mitogen-activated protein kinase), hypersensitive responses, phytohormone signaling pathways, photosynthesis, pigment metabolism, protein metabolism, sugar metabolism, and modification, and others were altered, which could be attributed to systemic symptom development upon CBCVd-infection in hop. In addition, genes encoding RNA-dependent RNA polymerase, pathogenesis-related protein, chitinase, as well as those related to basal defense responses were up-regulated. The expression levels of several genes identified from RNA sequencing analysis were confirmed by qRT-PCR. Our systematic comprehensive CBCVd-responsive transcriptome analysis provides a better understanding and insights into complex viroid-hop plant interaction. This information will assist further in the development of future measures for the prevention of CBCVd spread in hop fields.


Assuntos
Humulus/virologia , Doenças das Plantas/genética , Proteínas de Plantas/genética , Vírus de Plantas/fisiologia , Viroides/fisiologia , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Humulus/genética , Humulus/metabolismo , Doenças das Plantas/virologia , Folhas de Planta/genética , Folhas de Planta/metabolismo , Folhas de Planta/virologia , Proteínas de Plantas/metabolismo , Vírus de Plantas/genética , Vírus de Plantas/isolamento & purificação , Viroides/classificação , Viroides/genética , Viroides/isolamento & purificação
13.
Mol Metab ; 16: 76-87, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30120064

RESUMO

OBJECTIVES: Extracts of the hops plant have been shown to reduce weight and insulin resistance in rodents and humans, but elucidation of the mechanisms responsible for these benefits has been hindered by the use of heterogeneous hops-derived mixtures. Because hop extracts are used as flavoring agents for their bitter properties, we hypothesized that bitter taste receptors (Tas2rs) could be mediating their beneficial effects in metabolic disease. Studies have shown that exposure of cultured enteroendocrine cells to bitter tastants can stimulate release of hormones, including glucagon-like peptide 1 (GLP-1). These findings have led to the suggestion that activation of Tas2rs may be of benefit in diabetes, but this tenet has not been tested. Here, we have assessed the ability of a pure derivative of a hops isohumulone with anti-diabetic properties, KDT501, to signal through Tas2rs. We have further used this compound as a tool to systematically assess the impact of bitter taste receptor activation in obesity-diabetes. METHODS: KDT501 was tested in a panel of bitter taste receptor signaling assays. Diet-induced obese mice (DIO) were dosed orally with KDT501 and acute effects on glucose homeostasis determined. A wide range of metabolic parameters were evaluated in DIO mice chronically treated with KDT501 to establish the full impact of activating gut bitter taste signaling. RESULTS: We show that KDT501 signals through Tas2r108, one of 35 mouse Tas2rs. In DIO mice, acute treatment stimulated GLP-1 secretion and enhanced glucose tolerance. Chronic treatment caused weight and fat mass loss, increased energy expenditure, enhanced glucose tolerance and insulin sensitivity, normalized plasma lipids, and induced broad suppression of inflammatory markers. Chronic KDT501 treatment altered enteroendocrine hormone levels and bile acid homeostasis and stimulated sustained GLP-1 release. Combined treatment with a dipeptidyl peptidase IV inhibitor amplified the incretin-based benefits of this pure isohumulone. CONCLUSIONS: Activation of Tas2r108 in the gut results in a remodeling of enteroendocrine hormone release and bile acid metabolism that ameliorates multiple features of metabolic syndrome. Targeting extraoral bitter taste receptors may be useful in metabolic disease.


Assuntos
Ciclopentanos/metabolismo , Receptores Acoplados a Proteínas-G/metabolismo , Receptores Acoplados a Proteínas-G/fisiologia , Animais , Peso Corporal/efeitos dos fármacos , Ciclopentanos/farmacologia , Diabetes Mellitus Tipo 2/metabolismo , Modelos Animais de Doenças , Células Enteroendócrinas/metabolismo , Peptídeo 1 Semelhante ao Glucagon/efeitos dos fármacos , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Humulus/metabolismo , Hipoglicemiantes/farmacologia , Resistência à Insulina/fisiologia , Mucosa Intestinal/metabolismo , Intestinos/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos , Receptores Acoplados a Proteínas-G/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos
14.
J Chem Ecol ; 44(7-8): 711-726, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29978430

RESUMO

Phorodon humuli (Damson-hop aphid) is one of the major pests of hops in the northern hemisphere. It causes significant yield losses and reduces hop quality and economic value. Damson-hop aphid is currently controlled with insecticides, but the number of approved pesticides is steadily decreasing. In addition, the use of insecticides almost inevitably results in the development of resistant aphid genotypes. An integrated approach to pest management in hop cultivation is therefore badly needed in order to break this cycle and to prevent the selection of strains resistant to the few remaining registered insecticides. The backbone of such an integrated strategy is the breeding of hop cultivars that are resistant to Damson-hop aphid. However, up to date mechanisms of hops resistance towards Damson-hop aphids have not yet been unraveled. In the experiments presented here, we used metabolite profiling followed by multivariate analysis and show that metabolites responsible for hop aroma and flavor (sesquiterpenes) in the cones can also be found in the leaves, long before the hop cones develop, and may play a role in resistance against aphids. In addition, aphid feeding induced a change in the metabolome of all hop genotypes particularly an increase in a number of oxidized compounds, which suggests this may be part of a resistance mechanism.


Assuntos
Afídeos/fisiologia , Humulus/metabolismo , Humulus/parasitologia , Metaboloma , Metabolômica , Animais , Resistência à Doença , Cromatografia Gasosa-Espectrometria de Massas/métodos , Genótipo , Interações Hospedeiro-Parasita , Humulus/genética , Humulus/crescimento & desenvolvimento , Metabolômica/métodos , Melhoramento Vegetal , Doenças das Plantas/genética , Doenças das Plantas/parasitologia , Sesquiterpenos/metabolismo
15.
PLoS One ; 13(6): e0198971, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29894496

RESUMO

The vascular plant pathogen Verticillium nonalfalfae causes Verticillium wilt in several important crops. VnaSSP4.2 was recently discovered as a V. nonalfalfae virulence effector protein in the xylem sap of infected hop. Here, we expanded our search for candidate secreted effector proteins (CSEPs) in the V. nonalfalfae predicted secretome using a bioinformatic pipeline built on V. nonalfalfae genome data, RNA-Seq and proteomic studies of the interaction with hop. The secretome, rich in carbohydrate active enzymes, proteases, redox proteins and proteins involved in secondary metabolism, cellular processing and signaling, includes 263 CSEPs. Several homologs of known fungal effectors (LysM, NLPs, Hce2, Cerato-platanins, Cyanovirin-N lectins, hydrophobins and CFEM domain containing proteins) and avirulence determinants in the PHI database (Avr-Pita1 and MgSM1) were found. The majority of CSEPs were non-annotated and were narrowed down to 44 top priority candidates based on their likelihood of being effectors. These were examined by spatio-temporal gene expression profiling of infected hop. Among the highest in planta expressed CSEPs, five deletion mutants were tested in pathogenicity assays. A deletion mutant of VnaUn.279, a lethal pathotype specific gene with sequence similarity to SAM-dependent methyltransferase (LaeA), had lower infectivity and showed highly reduced virulence, but no changes in morphology, fungal growth or conidiation were observed. Several putative secreted effector proteins that probably contribute to V. nonalfalfae colonization of hop were identified in this study. Among them, LaeA gene homolog was found to act as a potential novel virulence effector of V. nonalfalfae. The combined results will serve for future characterization of V. nonalfalfae effectors, which will advance our understanding of Verticillium wilt disease.


Assuntos
Proteínas Fúngicas/metabolismo , Humulus/metabolismo , Doenças das Plantas/microbiologia , Proteoma/metabolismo , Verticillium/metabolismo , Xilema/metabolismo , Simulação por Computador , Regulação Fúngica da Expressão Gênica , Humulus/microbiologia , Verticillium/patogenicidade , Xilema/microbiologia
16.
Food Res Int ; 108: 42-47, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29735075

RESUMO

Thirty male merino lambs were fed with a pelleted total mixed ration (TMR) alone or supplemented with hop (Humulus lupulus L.) cones at two different doses (1.5 and 3.0 g hop cones/kg pelleted TMR, respectively), to study the effects of this dietary source of antioxidants on animal performance, ruminal parameters and meat quality attributes. The results showed that dietary supplementation with hop cones decreased lambs' growth rate (P < 0.05) due to a shift in ruminal fermentation, towards a more acetic and less propionic acid production (P < 0.05). These changes in animal growth rate might have promoted microstructural modifications in the quantity and size of muscle fibres, thereby inducing the differences observed in meat chemical composition, colour and texture (P < 0.05), regardless of the lack of differences in meat antioxidant status (P > 0.10).


Assuntos
Ração Animal , Antioxidantes/metabolismo , Suplementos Nutricionais , Fermentação , Qualidade dos Alimentos , Humulus/metabolismo , Músculo Esquelético/metabolismo , Carne Vermelha/análise , Rúmen/microbiologia , Criação de Animais Domésticos/métodos , Fenômenos Fisiológicos da Nutrição Animal , Animais , Antioxidantes/administração & dosagem , Cor , Culinária/métodos , Temperatura Alta , Masculino , Músculo Esquelético/crescimento & desenvolvimento , Carneiro Doméstico
17.
Plant Sci ; 269: 32-46, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29606215

RESUMO

Hop is an important source of medicinally valuable secondary metabolites including bioactive prenylated chalcones. To gain in-depth knowledge of the regulatory mechanisms of hop flavonoids biosynthesis, full-length cDNA of HlMyb8 transcription factor gene was isolated from lupulin glands. The deduced amino acid sequence of HlMyb8 showed high similarity to a flavonol-specific regulator of phenylpropanoid biosynthesis AtMYB12 from Arabidopsis thaliana. Transient expression studies and qRT-PCR analysis of transgenic hop plants overexpressing HlMyb8 revealed that HlMYB8 activates expression of chalcone synthase HlCHS_H1 as well as other structural genes from the flavonoid pathway branch leading to the production of flavonols (F3H, F'3H, FLS) but not prenylflavonoids (PT1, OMT1) or bitter acids (VPS, PT1). HlMyb8 could cross-activate Arabidopsis flavonol-specific genes but to a much lesser extent than AtMyb12. Reciprocally, AtMyb12 could cross-activate hop flavonol-specific genes. Transcriptome sequence analysis of hop leaf tissue overexpressing HlMyb8 confirmed the modulation of several other genes related to flavonoid biosynthesis pathways (PAL, 4CL, ANR, DFR, LDOX). Analysis of metabolites in hop female cones confirmed that overexpression of HlMyb8 does not increase prenylflavonoid or bitter acids content in lupulin glands. It follows from our results that HlMYB8 plays role in a competition between flavonol and prenylflavonoid or bitter acid pathways by diverting the flux of CHS_H1 gene product and thus, may influence the level of these metabolites in hop lupulin.


Assuntos
Flavonoides/biossíntese , Humulus/genética , Proteínas de Plantas/genética , Fatores de Transcrição/genética , Sequência de Aminoácidos , Perfilação da Expressão Gênica , Humulus/metabolismo , Filogenia , Folhas de Planta/metabolismo , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Alinhamento de Sequência , Tabaco/genética , Tabaco/metabolismo , Fatores de Transcrição/química , Fatores de Transcrição/metabolismo
18.
Anal Bioanal Chem ; 410(15): 3521-3531, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29350255

RESUMO

Humulus lupulus L. (hop) represents one of the most cultivated crops, it being a key ingredient in the brewing process. Many health-related properties have been described for hop extracts, making this plant gain more interest in the field of pharmaceutical and nutraceutical research. Among the analytical tools available for the phytochemical characterization of plant extracts, quantitative nuclear magnetic resonance (qNMR) represents a new and powerful technique. In this ambit, the present study was aimed at the development of a new, simple, and efficient qNMR method for the metabolite fingerprinting of bioactive compounds in hop cones, taking advantage of the novel ERETIC 2 tool. To the best of our knowledge, this is the first attempt to apply this method to complex matrices of natural origin, such as hop extracts. The qNMR method set up in this study was applied to the quantification of both prenylflavonoids and bitter acids in eight hop cultivars. The performance of this analytical method was compared with that of HPLC-UV/DAD, which represents the most frequently used technique in the field of natural product analysis. The quantitative data obtained for hop samples by means of the two aforementioned techniques highlighted that the amount of bioactive compounds was slightly higher when qNMR was applied, although the order of magnitude of the values was the same. The accuracy of qNMR was comparable to that of the chromatographic method, thus proving to be a reliable tool for the analysis of these secondary metabolites in hop extracts. Graphical abstract Graphical abstract related to the extraction and analytical methods applied in this work for the analysis of bioactive compounds in Humulus lupulus L. (hop) cones.


Assuntos
Ácidos/análise , Flavonoides/análise , Humulus/química , Extratos Vegetais/química , Ácidos/metabolismo , Cromatografia Líquida de Alta Pressão/métodos , Flavonoides/metabolismo , Humulus/metabolismo , Espectroscopia de Ressonância Magnética/métodos , Metaboloma , Extratos Vegetais/metabolismo , Metabolismo Secundário
19.
J Sci Food Agric ; 98(6): 2385-2392, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29023816

RESUMO

BACKGROUND: The effects of dietary levels of hop ß-acids on physical attributes, lipid oxidation and chemical composition of pork meat were evaluated. Thirty-two castrated male pigs obtained from a complete block design feeding experiment (6.23 ± 0.42 kg initial body weight (BW) to 20.45 ± 0.95 kg final BW) and fed diets supplemented with 0, 120, 240 or 360 mg kg-1 hop ß-acids during 35 days were slaughtered to sample longissimus dorsi muscle for meat analysis. RESULTS: No effects (P > 0.05) of dietary hop ß-acids were observed on meat physical attributes. Quadratic effects (P < 0.05) of hop ß-acids were observed on lipid and protein contents and on thiobarbituric acid-reactive substance (TBARS) values of meatballs, whose equations allowed the estimation of dietary hop ß-acid levels of 176, 169 and 181 mg kg-1 to provide up to 16.20% lipid reduction, 1.95% protein accretion and 23.31% TBARS reduction respectively. CONCLUSION: Dietary hop ß-acids fed to pigs might reduce lipid, increase protein and reduce lipid oxidation without affecting physical attributes of the pork meat. © 2017 Society of Chemical Industry.


Assuntos
Ácidos/metabolismo , Suplementos Nutricionais/análise , Humulus/metabolismo , Carne/análise , Suínos/metabolismo , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Humulus/química , Metabolismo dos Lipídeos , Lipídeos/química , Masculino , Músculo Esquelético/química , Músculo Esquelético/metabolismo , Oxirredução
20.
J Agric Food Chem ; 65(49): 10820-10828, 2017 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-29129062

RESUMO

Thiol-containing proteins have been suggested to have antioxidative properties in beer. A kinetic model has been setup for the reactivity of thiols during early stages of oxidative degradation of beer. Kinetic analysis based on the proposed reaction mechanism allowed evaluation of the relative reactivity of beer components, such as bitter acids from hops and polyphenols. The rate constants for the reaction of 1-hydroxyethyl radicals, which are generated during radical mediated oxidation of ethanol in beer, with hop bitter acids and thiols were very similar, and the concentration of these compounds in beer is therefore essential for the relative reactivity. For a standard pilsner beer with 35 international bitter units with typical concentrations of thiols and hop bitter acids, thiols were found to react with ca. 9% of 1-hydroxyethyl radicals, while bitter acids from hops accounted for ca. 88% of the reaction with 1-hydroxyethyl radicals. Polyphenols were not found to account for any major part of the reaction with 1-hydroxyethyl radicals due to low reaction rates and low concentrations in pilsner beer compared to the other components. The kinetic model suggests that the concentration of thiols has to be increased in order to contribute with any significant antioxidative protection and that the fate of thiols during oxidation must be considered since some thiol oxidation products may induce further damage.


Assuntos
Cerveja/análise , Humulus/química , Humulus/metabolismo , Proteínas/química , Compostos de Sulfidrila/química , Ácidos/química , Antioxidantes/química , Etanol/química , Análise de Alimentos/métodos , Humanos , Cinética , Simulação de Dinâmica Molecular , Polifenóis/química , Paladar
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