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Efficacy of geraniol but not of β-ionone or their combination for the chemoprevention of rat colon carcinogenesis

VIEIRA, A.; HEIDOR, R.; CARDOZO, M.T.; SCOLASTICI, C.; PURGATTO, E.; SHIGA, T.M.; BARBISAN, L.F.; ONG, T.P.; MORENO, F.S.
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica
Português
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37.342466%
β-ionone (βI), a cyclic isoprenoid, and geraniol (GO), an acyclic monoterpene, represent a promising class of dietary chemopreventive agents against cancer, whose combination could result in synergistic anticarcinogenic effects. The chemopreventive activities of βI and GO were evaluated individually or in combination during colon carcinogenesis induced by dimethylhydrazine in 48 3-week-old male Wistar rats (12 per group) weighing 40-50 g. Animals were treated for 9 consecutive weeks with βI (16 mg/100 g body weight), GO (25 mg/100 g body weight), βI combined with GO or corn oil (control). Number of total aberrant crypt foci (ACF) and of ACF ≥4 crypts in the distal colon was significantly lower in the GO group (66 ± 13 and 9 ± 2, respectively) compared to control (102 ± 9 and 17 ± 3) and without differences in the βI (91 ± 11 and 14 ± 3) and βI+GO groups (96 ± 5 and 19 ± 2). Apoptosis level, identified by classical apoptosis morphological criteria, in the distal colon was significantly higher in the GO group (1.64 ± 0.06 apoptotic cells/mm²) compared to control (0.91 ± 0.07 apoptotic cells/mm²). The GO group presented a 0.7-fold reduction in Bcl-2 protein expression (Western blot) compared to control. Colonic mucosa concentrations of βI and GO (gas chromatography/mass spectrometry) were higher in the βI and GO groups...

Chemopreventive effects of beta-ionone and geraniol during rat hepatocarcinogenesis promotion: distinct actions on cell proliferation, apoptosis, HMGCoA reductase, and RhoA

CARDOZO, Monica Testoni; CONTI, Aline de; ONG, Thomas Prates; SCOLASTICI, Clarissa; PURGATTO, Eduardo; HORST, Maria Aderuza; BASSOLI, Bruna Kempfer; MORENO, Fernando Salvador
Fonte: ELSEVIER SCIENCE INC Publicador: ELSEVIER SCIENCE INC
Tipo: Artigo de Revista Científica
Português
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Chemopreventive activities of the dietary isoprenoids beta-ionone (beta I) and geraniol (GOH) were evaluated during the promotion phase of hepatocarcinogenesis. Over 5 consecutive weeks, rats received daily 16 mg/100 g body weight (b.w.) of beta I (beta I group), 25 mg/100 g b.w. of GOH (GOH group), or only corn oil (CO group, controls). Compared to the CO group, the following was observed: only the beta I group showed a decrease in the mean number of visible hepatocyte nodules (P<.05); beta I and GOH groups had reduced mean number of persistent preneoplastic lesions (pPNLs) (P<.05), but no differences regarding number of remodeling PNL (rPNLs) were observed; only the beta I group exhibited smaller rPNL size and percentage of liver sections occupied by pPNLs (P<.05), whereas the GOH group displayed a smaller percentage of liver sections occupied by rPNLs (P<.05); a trend was observed in the beta I group, which showed reduced cell proliferation of pPNLs (P<.10), and the GOH group had increased apoptosis in pPNLs and rPNLs (P<.05); only the beta I group displayed reduced total plasma cholesterol concentrations (P<.05) and increased hepatic 3-hydroxy-3-methylglutaryl coenzyme A (HMGCoA) reductase mRNA levels (P<.05): only the GOH group had lower hepatic membrane RhoA protein levels (P<.05); both the beta I- and GOH-treated groups had higher hepatic concentrations of beta I and GOH...

Atividade quimiopreventiva do farnesol e geraniol em ratos Wistar submetidos ao modelo de hepatocarcinogênese do 'hepatócito resistente'"; Farnesol and gernariol chemopreventive activity in Wistar rats submitted to the "resistant hepatocyte"model of hepatocarcinogenesis

Ong, Thomas Prates
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 17/06/2004 Português
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No presente estudo avaliou-se a atividade quimiopreventiva do farnesol (FR) e geraniol (GR), isoprenóides presentes em frutas e ervas, quando administrados a ratos Wistar durante as etapas de iniciação e/ou seleção/promoção do modelo de hepatocarcinogênese do "hepatócito resistente" (RH). No Protocolo Experimental 1, os animais receberam durante 8 semanas consecutivas, continuamente durante as etapas de iniciação e seleção/promoção, por entubação gástrica e dissolvido em óleo de milho (OM): FR (25 mg/100 g de peso corpóreo [p.c.]; grupo FR) ou GR (25 mg/100 g de p.c.; grupo GR). Além disso, 1 grupo recebeu durante o mesmo período, por entubação gástrica, apenas OM (0,25 mL/100 g de p.c.; grupo OM; controle). Duas semanas após o início dos tratamentos, todos os grupos foram submetidos ao modelo do RH. Esse consistiu na aplicação intraperitoneal de uma dose do agente iniciante dietilnitrosamina (DEN, 20 mg/100 g de p.c.), seguida, 2 semanas após, da aplicação de 4 doses consecutivas de 2-acetilaminofluoreno (2-AAF; 2,5 mg/100 g de p.c.) e de uma hepatectomia parcial (HP) a 70%, acrescida de 2 doses de 2-AAF (2 mg/100 g de p.c.) 2 e 4 dias após a cirurgia. Decorridas 6 semanas após a iniciação com DEN...

Atividade quimiopreventiva do geraniol e β-ionona quando administrados isoladamente ou em associação a ratos durante a fase de promoção da hepatocarcinogênese; Chemopreventive activity of geraniol and β-ionona when administrated alone or in combination during the promotion phase of hepatocarcinogenesis in rats.

Cardozo, Mônica Testoni
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 03/07/2007 Português
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Foram avaliados as atividades quimiopreventivas da β-ionona (BI) e do geraniol (GR) durante a etapa de promoção da hepatocarcinogênese. Ratos Wistar foram submetidos ao modelo de hepatocarcinogênese do "Hepatócito Resistente" e receberam durante 5 semanas consecutivas: 16 mg/100 g p.c. de BI, 25 mg/100 g p.c. de GR, 16 mg/100 g p.c. de BI + 25 mg/100 g p.c. de GR ou somente 25 ml/100 g p.c. de óleo de milho (grupo OM, controle). Em comparação ao grupo OM, o grupo BI apresentou menor multiplicidade de nódulos hepáticos e os grupos BI, GR e GR+BI apresentaram menor número de lesões pré-neoplásicas (LPN) persistentes e maior porcentagem de LPN em remodelação. Comparados ao grupo OM, o grupo BI apresentou menor área de LPN em remodelação e menor porcentagem da área do corte histológico ocupado por LPN persistentes enquanto o grupo GR apresentou menor porcentagem da área do corte histológico ocupado por LPN em remodelação. O tratamento com BI tendeu a reduzir o colesterol plasmático e inibir a proliferação celular em LPN. O grupo GR apresentou maior número de corpúsculos apoptóticos em LPN persistentes em comparação ao grupo OM. Comparados ao grupo OM, os grupos BI e GR+BI apresentaram menor porcentagem de LPN hepáticas em remodelação positivas para a proteína p53 citoplasmática. Já o grupo GR apresentou maior porcentagem de LPN hepáticas persistentes positivas para p53. Os níveis da proteína RhoA nas membranas celulares hepáticas foram menores no grupo GR quando comparados aos do grupo OM. Assim...

Geraniol, mas não beta-ionona ou associação desses isoprenóides, possui atividade quimiopreventiva em ratos submetidos a modelo de carcinogênese de cólon; Geraniol, but not beta-ionone or association this isoprenoids, has chemopreventive activity in rats submitted to model of colon carcinogenesis

Vieira, Alessandra
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 05/10/2007 Português
Relevância na Pesquisa
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Diversos estudos epidemiológicos têm demonstrado que isoprenóides presentes em frutas e hortaliças possuem ação protetora contra o desenvolvimento de câncer. Objetivou-se, no presente trabalho, avaliar as eventuais atividades quimiopreventivas dos isoprenóides geraniol (GO) e beta-ionona (BI) quando administrados a ratos Wistar, isoladamente ou em associação, continuamente durante as etapas de iniciação e pós-iniciação de modelo de carcinogênese de cólon induzida por dimetilhidrazina. A atividade quimiopreventiva desses compostos foi observada microscopicamente por meio da análise de Focos de Criptas Aberrantes (FCAs) em cólons corados com azul de metileno (0,02%). Verificou-se que, em comparação ao grupo controle apenas os ratos tratados com GO, mas não com BI, apresentaram redução (p≤0,05) do número de lesões pré-neoplásicas (FCAs), no cólon distal, tanto em relação ao número de focos totais quanto aqueles com número maior ou igual do que quatro criptas. Por outro lado, somente tratamento com BI foi capaz de reduzir a concentração de colesterol plasmático total. Posteriormente, raspagem da mucosa colônica foi utilizada para a avaliação de danos no DNA pelo método do "Cometa". Em comparação ao grupo controle...

Efeitos de diferentes doses de geraniol em categorias de lesões pré-neoplásicas induzidas durante a fase de pós-iniciação tardia da carcinogênese experimental de cólon; Effects of different doses of geraniol on preneoplastic lesions induced during late post-initiation in an experimental model of colon carcinogenesis

Vieira, Alessandra
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 11/10/2011 Português
Relevância na Pesquisa
37.732878%
O isoprenóide geraniol (GO) apresentou atividade quimiopreventiva quando administrado continuamente durante as fases de iniciação e pós-iniciação em modelo de carcinogênese experimental de cólon por meio da redução do número de focos de criptas aberrantes (FCAs) totais FCAs ≥ 4 criptas e aumento de apoptose no cólon distal. Dessa forma, optou-se por avaliar os eventuais efeitos de três doses de GO (GO1: 25mg/100g de peso corpóreo [p.c.], G02: 50 mg/100g de p.c. e G03: 100 mg/100g de p.c.) em categorias de lesões pré-neoplásicas (LPNs) induzidas por dimetilhidrazina (DMH) durante a fase de pós-iniciação tardia de modelo de carcinogênese experimental de cólon, caracterizada por apresentar lesões mais avançadas e com alto grau de alterações celulares morfológicas, bioquímicas e moleculares denominadas de displasia. Para isso, analisamos diferentes biomarcadores como: FCAs totais e FCAs < ou ≥ 4 criptas em cólons corados com azul de metileno; focos depletados ou positivos de mucina (FPMs ou FDMs) em cólons corados com azul de toluidina; FCAs convencionais ou displásicos por meio de análise histopatológica em cortes corados com hematoxilina e eosina (HE) e focos positivos ou negativos para beta-catenina (FPBCs ou FNBCs) citoplasmática e/ou nuclear por meio de imunoistoquímica. Além disso...

Efficacy of geraniol but not of β-ionone or their combination for the chemoprevention of rat colon carcinogenesis

Vieira, A.; Heidor, R.; Cardozo, M. T.; Scolastici, C.; Purgatto, E.; Shiga, T. M.; Barbisan, L. F.; Ong, T. P.; Moreno, F. S.
Fonte: Associação Brasileira de Divulgação Científica (ABRADIC) Publicador: Associação Brasileira de Divulgação Científica (ABRADIC)
Tipo: Artigo de Revista Científica Formato: 538-545
Português
Relevância na Pesquisa
37.342466%
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); β-ionone (βI), a cyclic isoprenoid, and geraniol (GO), an acyclic monoterpene, represent a promising class of dietary chemopreventive agents against cancer, whose combination could result in synergistic anticarcinogenic effects. The chemopreventive activities of βI and GO were evaluated individually or in combination during colon carcinogenesis induced by dimethylhydrazine in 48 3-week-old male Wistar rats (12 per group) weighing 40-50 g. Animals were treated for 9 consecutive weeks with βI (16 mg/100 g body weight), GO (25 mg/100 g body weight), βI combined with GO or corn oil (control). Number of total aberrant crypt foci (ACF) and of ACF ≥4 crypts in the distal colon was significantly lower in the GO group (66 ± 13 and 9 ± 2, respectively) compared to control (102 ± 9 and 17 ± 3) and without differences in the βI (91 ± 11 and 14 ± 3) and βI+GO groups (96 ± 5 and 19 ± 2). Apoptosis level, identified by classical apoptosis morphological criteria, in the distal colon was significantly higher in the GO group (1.64 ± 0.06 apoptotic cells/mm²) compared to control (0.91 ± 0.07 apoptotic cells/mm²). The GO group presented a 0.7-fold reduction in Bcl-2 protein expression (Western blot) compared to control. Colonic mucosa concentrations of βI and GO (gas chromatography/mass spectrometry) were higher in the βI and GO groups...

Geraniol-a flavoring agent with multifunctional effects in protecting the gastric and duodenal mucosa

Moraes de Carvalho, Katharinne Ingrid; Bonamin, Flavia; Santos, Raquel Cassia dos; Perico, Larissa Lucena; Beserra, Fernando Pereira; Sousa, Damio Pergentino de; Barbosa Filho, Jose Maria; Machado da Rocha, Lucia Regina; Hiruma-Lima, Clelia Akiko
Fonte: Springer Publicador: Springer
Tipo: Artigo de Revista Científica Formato: 355-365
Português
Relevância na Pesquisa
37.893638%
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Geraniol is an acyclic monoterpene alcohol commonly used as a flavoring agent. The present study was undertaken to investigate antiulcerogenic effects of geraniol and to determine the possible mechanisms involved in this action. In the model of the ethanol-induced ulcer, treatment of rats with geraniol by oral route significantly inhibited gastric lesions by 70 % (7.50 mg/kg) to 99 % (200 mg/kg). Analysis of the gastric tissue of rats treated with geraniol (7.50 mg/kg) revealed that total glutathione content levels (GSH) increased and levels of myeloperoxidase (MPO) decreased in the gastric mucosa. Oral treatment with geraniol significantly decreased the number of ulcerative lesions induced by ischemia/reperfusion injury by 71 % and the duodenal ulcers induced by cysteamine by 68 %. The action of geraniol was mediated by the activation of defensive mucosa-protective factors such as the nitric oxide (NO) pathway, endogenous prostaglandins, increased mucus production, increased sulfhydryl compounds, antioxidant properties and the stimulation of calcitonin gene-related peptide (CGRP) release through the activation of transient receptor potential vanilloid (TRPV). The multifaceted gastroprotective mechanisms of geraniol represent a promising option for the treatment of gastric and duodenal mucosa injury.

Cymbopogon martinii essential oil and geraniol at noncytotoxic concentrations exerted immunomodulatory/anti-inflammatory effects in human monocytes

Murbach Teles Andrade, Bruna Fernanda; Conti, Bruno Jose; Santiago, Karina Basso; Fernandes Junior, Ary; Sforcin, Jose Mauricio
Fonte: Wiley-Blackwell Publicador: Wiley-Blackwell
Tipo: Artigo de Revista Científica Formato: 1491-1496
Português
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ObjectivesIn traditional medicine, plants have formed the basis of sophisticated systems that have been in existence for thousands of years and still provide mankind with new remedies. Cymbopogon martinii, known as palmarosa, has been used in aromatherapy as a skin tonic due to its antimicrobial properties. It has also used in Ayurvedic medicine for skin problems and to relieve nerve pain. The immunomodulatory action of C.martinii essential oil (EO) and geraniol was evaluated regarding the production of pro- and anti-inflammatory cytokines (tumour necrosis factor (TNF)- and IL-10, respectively) by human monocytes in vitro.MethodsMonocyte cultures were incubated with EO or geraniol. After 18h, cytotoxicity assays were performed using 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide method, and cytokine production was determined by ELISA.Key findingsThe variables showed no cytotoxic effects on monocytes. TNF- production was not affected by C.martinii and geraniol, and only the concentration of 5g/ml of C.martinii stimulated its production. On the other hand, all concentrations of C.martinii and geraniol increased IL-10 production by human monocytes.ConclusionsData showed that noncytotoxic concentrations of EO and geraniol exerted an anti-inflammatory action by increasing IL-10 production; moreover...

In vitro larvicidal activity of geraniol and citronellal against Contracaecum sp (Nematoda: Anisakidae)

Barros,L.A.; Yamanaka,A.R.; Silva,L.E.; Vanzeler,M.L.A.; Braum,D.T.; Bonaldo,J.
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/10/2009 Português
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Human infection with fish parasites can result from the ingestion of incompletely cooked or raw fish, giving origin to parasitic diseases such as anisakiasis, caused by parasites of the Anisakidae family. The present study assessed the in vitro larvicidal effect of two monoterpene compounds, geraniol and citronellal, against Contracaecum sp (Nematoda: Anisakidae). Four hundred live larvae of Contracaecum sp obtained from "traíra" fish (Hoplias malabaricus, Bloch, 1974) were analyzed on 40 Petri dishes (10 larvae each) with the compounds to be tested. The final concentrations tested for each compound were 250, 125, 62.5, and 31.2 µg/mL and the evaluation was carried out at five different times (2, 4, 8, 24, and 48 h). The larvicidal action of geraniol and citronellal was statistically superior (P < 0.005) to the control (1% ethanol) at concentrations of 250 and 31.2 µg/mL (geraniol) and 250, 125, and 62.5 μg/mL (citronellal). However, no larvicidal activity was observed at concentrations of 125 and 62.5 µg/mL for geraniol and 31.2 µg/mL for citronellal. When the larvicidal action of geraniol was compared to that of citronellal, the former was found to be statistically superior (P < 0.05) to the latter at concentrations of 250 and 31.2 μg/mL. On the other hand...

Efficacy of geraniol but not of β-ionone or their combination for the chemoprevention of rat colon carcinogenesis

Vieira,A.; Heidor,R.; Cardozo,M.T.; Scolastici,C.; Purgatto,E.; Shiga,T.M.; Barbisan,L.F.; Ong,T.P.; Moreno,F.S.
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2011 Português
Relevância na Pesquisa
37.342466%
β-ionone (βI), a cyclic isoprenoid, and geraniol (GO), an acyclic monoterpene, represent a promising class of dietary chemopreventive agents against cancer, whose combination could result in synergistic anticarcinogenic effects. The chemopreventive activities of βI and GO were evaluated individually or in combination during colon carcinogenesis induced by dimethylhydrazine in 48 3-week-old male Wistar rats (12 per group) weighing 40-50 g. Animals were treated for 9 consecutive weeks with βI (16 mg/100 g body weight), GO (25 mg/100 g body weight), βI combined with GO or corn oil (control). Number of total aberrant crypt foci (ACF) and of ACF ≥4 crypts in the distal colon was significantly lower in the GO group (66 ± 13 and 9 ± 2, respectively) compared to control (102 ± 9 and 17 ± 3) and without differences in the βI (91 ± 11 and 14 ± 3) and βI+GO groups (96 ± 5 and 19 ± 2). Apoptosis level, identified by classical apoptosis morphological criteria, in the distal colon was significantly higher in the GO group (1.64 ± 0.06 apoptotic cells/mm²) compared to control (0.91 ± 0.07 apoptotic cells/mm²). The GO group presented a 0.7-fold reduction in Bcl-2 protein expression (Western blot) compared to control. Colonic mucosa concentrations of βI and GO (gas chromatography/mass spectrometry) were higher in the βI and GO groups...

Characterization of Geraniol Synthase from the Peltate Glands of Sweet Basil1

Iijima, Yoko; Gang, David R.; Fridman, Eyal; Lewinsohn, Efraim; Pichersky, Eran
Fonte: The American Society for Plant Biologists Publicador: The American Society for Plant Biologists
Tipo: Artigo de Revista Científica
Publicado em /01/2004 Português
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27.8517%
The monoterpene fraction of the lemon-scented sweet basil (Ocimum basilicum) cv Sweet Dani consists mostly of citral (a mixture of geranial and neral), with lower levels of geraniol and nerol. These compounds are stored in the peltate glands found on the leaf epidermis. Younger leaves, which have a higher density of such glands, also have a higher content of monoterpenes than older leaves. Geraniol synthase (GES) activity, generating geraniol from geranyl diphosphate, was shown to be localized exclusively or almost exclusively to glands. GES activity resides in a homodimeric protein that was purified to near homogeneity. Basil GES requires Mn2+ as a divalent metal cofactor for activity and produces only geraniol from geranyl diphosphate. Km values of 21 and 51 μm were obtained for geranyl diphosphate and Mn2+, respectively. In the presence of 18O-labeled water, GES catalyzed the formation of 18O-geraniol from geranyl diphosphate, indicating that the reaction mechanism of GES is similar to that of other monoterpene synthases and is different from the action of phosphatases. A GES cDNA was isolated based on analysis of a glandular trichome expressed sequence tag database, and the sequence of the protein encoded by this cDNA shows some similarity to sequences of other terpene synthases. The expression of the GES cDNA in Escherichia coli resulted in a protein with enzymatic activity essentially identical to that of plant-purified GES. RNA gel-blot analysis indicated that GES is expressed in glands but not in leaves of basil cv Sweet Dani...

Geraniol and Geranial Dehydrogenases Induced in Anaerobic Monoterpene Degradation by Castellaniella defragrans

Lüddeke, Frauke; Wülfing, Annika; Timke, Markus; Germer, Frauke; Weber, Johanna; Dikfidan, Aytac; Rahnfeld, Tobias; Linder, Dietmar; Meyerdierks, Anke; Harder, Jens
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /04/2012 Português
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Castellaniella defragrans is a Betaproteobacterium capable of coupling the oxidation of monoterpenes with denitrification. Geraniol dehydrogenase (GeDH) activity was induced during growth with limonene in comparison to growth with acetate. The N-terminal sequence of the purified enzyme directed the cloning of the corresponding open reading frame (ORF), the first bacterial gene for a GeDH (geoA, for geraniol oxidation pathway). The C. defragrans geraniol dehydrogenase is a homodimeric enzyme that affiliates with the zinc-containing benzyl alcohol dehydrogenases in the superfamily of medium-chain-length dehydrogenases/reductases (MDR). The purified enzyme most efficiently catalyzes the oxidation of perillyl alcohol (kcat/Km = 2.02 × 106 M−1 s−1), followed by geraniol (kcat/Km = 1.57 × 106 M−1 s−1). Apparent Km values of <10 μM are consistent with an in vivo toxicity of geraniol above 5 μM. In the genetic vicinity of geoA is a putative aldehyde dehydrogenase that was named geoB and identified as a highly abundant protein during growth with phellandrene. Extracts of Escherichia coli expressing geoB demonstrated in vitro a geranial dehydrogenase (GaDH) activity. GaDH activity was independent of coenzyme A. The irreversible formation of geranic acid allows for a metabolic flux from β-myrcene via linalool...

Assessment of Cultivation Factors that Affect Biomass and Geraniol Production in Transgenic Tobacco Cell Suspension Cultures

Vasilev, Nikolay; Schmitz, Christian; Grömping, Ulrike; Fischer, Rainer; Schillberg, Stefan
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 12/08/2014 Português
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A large-scale statistical experimental design was used to determine essential cultivation parameters that affect biomass accumulation and geraniol production in transgenic tobacco (Nicotiana tabacum cv. Samsun NN) cell suspension cultures. The carbohydrate source played a major role in determining the geraniol yield and factors such as filling volume, inoculum size and light were less important. Sucrose, filling volume and inoculum size had a positive effect on geraniol yield by boosting growth of plant cell cultures whereas illumination of the cultures stimulated the geraniol biosynthesis. We also found that the carbohydrates sucrose and mannitol showed polarizing effects on biomass and geraniol accumulation. Factors such as shaking frequency, the presence of conditioned medium and solubilizers had minor influence on both plant cell growth and geraniol content. When cells were cultivated under the screened conditions for all the investigated factors, the cultures produced ∼5.2 mg/l geraniol after 12 days of cultivation in shaking flasks which is comparable to the yield obtained in microbial expression systems. Our data suggest that industrial experimental designs based on orthogonal arrays are suitable for the selection of initial cultivation parameters prior to the essential medium optimization steps. Such designs are particularly beneficial in the early optimization steps when many factors must be screened...

Identification of enzymes responsible for the reduction of geraniol to citronellol

Yuan, Tian-Tian; Chen, Qian-Qian; Zhao, Pei-Ji; Zeng, Ying; Liu, Xiao-Zhu; Lu, Shan
Fonte: Springer-Verlag Publicador: Springer-Verlag
Tipo: Artigo de Revista Científica
Publicado em 13/12/2011 Português
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The reduction of geraniol to citronellol is the first step for the synthesis of natural phytol in the production of tocopherols and natural vitamin K. Baker’s yeast was used in the bioreduction described above as a whole-cell biocatalyst. However, the enzyme responsible for the reduction of geraniol to citronellol is not yet known. Four old yellow enzyme (OYE) genes were cloned from yeast and plants, and expressed in Escherichia coli for a high level of recombinant proteins. The recombinant protein displayed a catalytic activity of converting geraniol to citronellol as a sole product verified by GC-MS analyses. The recombinant OYE2 intact cells were found to show 3.7 and 1.9-fold higher activity than that of yeast cells and the recombinant crude extracts, respectively. Compared to the recombinant fusion enzyme, the entrokinase-cleaved enzyme displayed nearly identical activity for geraniol reduction. To our knowledge, this is the first enzyme identified to catalyze the formation of citronellol from geraniol by reducing the allylic alcohol double bond, which is normally known as inactivating group for the old yellow enzymes.

Effect of Inhaling Cymbopogon martinii Essential Oil and Geraniol on Serum Biochemistry Parameters and Oxidative Stress in Rats

Andrade, Bruna Fernanda Murbach Teles; Braga, Camila Pereira; dos Santos, Klinsmann Carolo; Barbosa, Lidiane Nunes; Rall, Vera Lúcia Mores; Sforcin, José Maurício; Fernandes, Ana Angélica Henrique; Fernandes Júnior, Ary
Fonte: Hindawi Publishing Corporation Publicador: Hindawi Publishing Corporation
Tipo: Artigo de Revista Científica
Português
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The effects of the inhalation of Cymbopogon martinii essential oil (EO) and geraniol on Wistar rats were evaluated for biochemical parameters and hepatic oxidative stress. Wistar rats were divided into three groups (n = 8): G1 was control group, treated with saline solution; G2 received geraniol; and G3 received C. martinii EO by inhalation during 30 days. No significant differences were observed in glycemia and triacylglycerol levels; G2 and G3 decreased (P < 0.05) total cholesterol level. There were no differences in serum protein, urea, aspartate aminotransferase activity, and total hepatic protein. Creatinine levels increased in G2 but decreased in G3. Alanine aminotransferase activity and lipid hydroperoxide were higher in G2 than in G3. Catalase and superoxide dismutase activities were higher in G3. C. martinii EO and geraniol increased glutathione peroxidase. Oxidative stress caused by geraniol may have triggered some degree of hepatic toxicity, as verified by the increase in serum creatinine and alanine aminotransferase. Therefore, the beneficial effects of EO on oxidative stress can prevent the toxicity in the liver. This proves possible interactions between geraniol and numerous chemical compounds present in C. martinii EO.

Geraniol Suppresses Angiogenesis by Downregulating Vascular Endothelial Growth Factor (VEGF)/VEGFR-2 Signaling

Wittig, Christine; Scheuer, Claudia; Parakenings, Julia; Menger, Michael D.; Laschke, Matthias W.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 08/07/2015 Português
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Geraniol exerts several direct pharmacological effects on tumor cells and, thus, has been suggested as a promising anti-cancer compound. Because vascularization is a major precondition for tumor growth, we analyzed in this study the anti-angiogenic action of geraniol. In vitro, geraniol reduced the migratory activity of endothelial-like eEND2 cells. Western blot analyses further revealed that geraniol downregulates proliferating cell nuclear antigen (PCNA) and upregulates cleaved caspase-3 (Casp-3) expression in eEND2 cells. Moreover, geraniol blocked vascular endothelial growth factor (VEGF)/VEGFR-2 signal transduction, resulting in a suppression of downstream AKT and ERK signaling pathways. In addition, geraniol significantly reduced vascular sprout formation in a rat aortic ring assay. In vivo, geraniol inhibited the vascularization of CT26 tumors in dorsal skinfold chambers of BALB/c mice, which was associated with a smaller tumor size when compared to vehicle-treated controls. Immunohistochemical analyses confirmed a decreased number of Ki67-positive cells and CD31-positive microvessels with reduced VEGFR-2 expression within geraniol-treated tumors. Taken together, these findings indicate that geraniol targets multiple angiogenic mechanisms and...

Production of geraniol by honey bees of various ages

Boch, R.; Shearer, D.A.
Fonte: INRA - Instituto Nacional de Investigação Agronômica da França Publicador: INRA - Instituto Nacional de Investigação Agronômica da França
Tipo: Journal Article-postprint
Português
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The amount of geraniol obtained by a standard procedure from the Nassanoff gland of the honey bee varied from zero to 1·5 μg per bee, depending on the age of the bees. Newly emerged bees had no geraniol. Guard bees produced ca. 0·3 μg per bee and a marked increase to ca. 1·0 μg per bee occurred when the bees began to forage.

Quantitative analysis of geraniol, nerol, linalool, and a-terpineol in wine

Pedersen, D.; Capone, D.; Skouroumounis, G.; Pollnitz, A.; Sefton, M.
Fonte: Springer-Verlag Publicador: Springer-Verlag
Tipo: Artigo de Revista Científica
Publicado em //2003 Português
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A mixture of [²H₇]-geraniol, [²H₇]-nerol, [²H₇]-linalool and [²H₇]-f-terpineol was prepared for use as internal standards in a rapid and accurate analytical method, employing gas chromatography-mass spectrometry (GC/MS), to determine the concentration of geraniol, nerol, linalool and f-terpineol in wine. The method avoids the possible formation, degradation and interconversion of these compounds during their analysis.

Inhibitory effect of Rosa damascena Mill flower essential oil, geraniol and citronellol on rat ileum contraction

Sadraei, H.; Asghari, G.; Emami, S.
Fonte: Medknow Publications & Media Pvt Ltd Publicador: Medknow Publications & Media Pvt Ltd
Tipo: Artigo de Revista Científica
Publicado em //2013 Português
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Flower of Rosa damascena Mill is widely used in Iran for gastrointestinal (GI) disorders. However, its pharmacological action on ileum contraction has not been studied. In this research we have investigated ileum motility effect of essential oil of flower petals of R. damascena growing in Kashan, Iran, and two of its constituents. The essential oils obtained by hydrodistillation were investigated by a combination of GC and GC/MS. More than 34 compounds have been identified. The main constituents of the essential oil were β-citronellol (23%), nonadecane (16%), geraniol (16%) and heneicosane (5%). A portion of rat isolated ileum was suspended under 1g tension in Tyrode's solution at 37°C and gassed with O2. Effect of the R. damascena essential oil (2.5-160 μg/ml), geraniol (0.2-3.2 μg/ml) and citronellol (0.8-6.4 μg/ml) were studied on ileum contractions induced by KCl, acetylcholine (ACh) and electrical field stimulation (EFS) and compared with standard drugs atropine and loperamide. The contractile response of EFS was mediated mainly through the intramural nerve plexuses, because its response was inhibited by loperamide and partially reduced by atropine. The essential oil concentration dependently inhibited the response to KCl (IC50=67 ± 8.4μg/ml) and EFS (IC50=47 ± 10.6 μg/ml). Geraniol (IC50=1.7 ± 0.15 μg/ml for KCl) and citronellol (IC50=2.9 ± 0.3 μg/ml for KCl) also had inhibitory effect of ileum contraction and both were more potent than the essential oil. It was concluded that R. damascena essential oil mainly had an inhibitory effect on ileum contractions and geraniol and citronellol had a major role in inhibitory effect of the essential.