Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 6.033
Filtrar
1.
Int J Mol Sci ; 20(20)2019 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-31614552

RESUMO

The incidence of diabetes mellitus (DM) is increasing rapidly and is associated with changes in dietary habits. Although restrictions in the use of sweeteners may prevent the development of DM, this might reduce the quality of life of patients with DM. Therefore, there has been a great deal of research into alternative sweeteners. In the search for such sweeteners, we analyzed the carbohydrate content of maple syrup and identified a novel oligosaccharide composed of fructose and glucose, linked at the C-4 of glucose and the C-6 of fructose. This oligosaccharide inhibited the release of fructose from sucrose by invertase (IC50: 1.17 mmol/L) and the decomposition of maltose by α-(1-4) glucosidase (IC50: 1.72 mmol/L). In addition, when orally administered together with sucrose to rats with DM, the subsequent plasma glucose concentrations were significantly lower than if the rats had been administered sucrose alone, without having any effect on the insulin concentration. These findings suggest that this novel oligosaccharide might represent a useful alternative sweetener for inclusion in the diet of patients with DM and may also have therapeutic benefits.


Assuntos
Acer/química , Diabetes Mellitus Tipo 2/dietoterapia , Oligossacarídeos/administração & dosagem , Sacarose/administração & dosagem , Administração Oral , Animais , Glicemia/efeitos dos fármacos , Diabetes Mellitus Tipo 2/sangue , Humanos , Insulina/sangue , Oligossacarídeos/química , Oligossacarídeos/farmacologia , Extratos Vegetais/química , Ratos , Sacarose/farmacologia
2.
Can J Microbiol ; 65(12): 895-903, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31479619

RESUMO

Bacteriocins are antimicrobial peptides, produced by Gram-positive bacteria such as lactococci and staphylococci, that have limited bactericidal action against Gram-negative bacteria. The aim of this paper was to study the sensitivity of three strains of Escherichia coli to bacteriocins: nisin (as Nisaplin®) and two staphylococcal peptides (warnerin and hominin) during sucrose-induced osmotic stress. We found that all peptides in a 0.3 g·mL-1 sucrose solution significantly reduced the number of viable E. coli. The most pronounced antibacterial effect was achieved by nisin against E. coli K-12 (3 log reduction). Slightly less bactericidal effects were observed with warnerin (1 mg·mL-1) and hominin (1 mg·mL-1) in sucrose solution. The lytic activity of staphylococcal peptides was detected by decreased optical density and viable cell counts. Moreover, it was confirmed by the increased amount of DNA and protein in the medium and the morphological changes detected by atomic force microscopy after 20 h of treatment. Zymographic analysis revealed the release of lytic enzymes from E. coli cells after treatment with staphylococcal peptides and sucrose. These results indicated that the antimicrobial action of peptides can be extended to Gram-negative bacteria via combination with high concentrations of sucrose.


Assuntos
Antibacterianos/farmacologia , Bacteriocinas/farmacologia , Escherichia coli/efeitos dos fármacos , Pressão Osmótica , Sacarose/farmacologia , Antibacterianos/metabolismo , Bacteriocinas/metabolismo , Bacteriólise/efeitos dos fármacos , Bactérias Gram-Positivas/metabolismo , Viabilidade Microbiana/efeitos dos fármacos
3.
Expert Opin Drug Metab Toxicol ; 15(9): 697-703, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31382802

RESUMO

Background: D-chiro-inositol (DCI) and glucose transporter inhibitors may inhibit myo-inositol (MI) transporters, and the aim is to clinically evaluate their effect on MI absorption. Research design and methods: Fasting 18 healthy volunteers received orally 6000 mg MI, 6000 mg MI with 1000 mg DCI, and 6000 mg MI with SelectSIEVE® Apple PCQ and Sorbitol, Maltodextrin and Sucralose (PCQ-SMS), in three different phases with a washout period of 7 days. At each phase, blood samples were collected before administration, and every 60 minutes until 540 minutes after administration. MI plasma levels (µmol/L) were quantified by gas chromatography-mass spectrometry; maximum plasma concentration (Cmax), time to reach it (Tmax), and the area under the time-concentration curve of MI (AUC 0-540) were evaluated. Results: The Cmax of MI alone (Tmax = 180min) was 1.29-fold higher than those of MI with DCI (Tmax = 180min) (p < 0.001) and 1.69-fold higher than those of MI with PCQ-SMS (Tmax = 240min) (p < 0.001). The AUC 0-540 was reduced by 19.09% in MI plus DCI (p = 0.0118) and by 31.8% in MI plus PCQ-SMS (p < 0.001) as compared to MI alone. Conclusions: DCI, glucose transporter inhibitors and sugars, such as sorbitol and maltodextrin, seem to inhibit MI absorption, decreasing MI plasma concentration as compared to MI alone.


Assuntos
Proteínas Facilitadoras de Transporte de Glucose/antagonistas & inibidores , Inositol/administração & dosagem , Absorção Intestinal , Adulto , Área Sob a Curva , Transporte Biológico , Interações de Medicamentos , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Inositol/farmacocinética , Masculino , Polissacarídeos/administração & dosagem , Polissacarídeos/farmacologia , Sorbitol/administração & dosagem , Sorbitol/farmacologia , Sacarose/administração & dosagem , Sacarose/análogos & derivados , Sacarose/farmacologia , Fatores de Tempo , Adulto Jovem
4.
J Coll Physicians Surg Pak ; 29(9): 848-851, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31455480

RESUMO

OBJECTIVE: To determine the cytoplasmic fatty change of rat liver due to artificial sweeteners - aspartame and sucralose. STUDY DESIGN: Experimental study. PLACE AND DURATION OF STUDY: Department of Anatomy, King Edward Medical University, Lahore, in collaboration with the University of Veterinary and Animal Sciences Lahore, from May to October 2016. METHODOLOGY: Adult Wistar albino rats were randomly divided into five groups. Group I was control group (animals were given drinking water by oral gavage). The animals of group II and III were given low (40 mg/kg body weight) and high dose (1000 mg/kg body weight) of aspartame, respectively. Animals of group IV and V were given low (5 mg/kg body weight) and high dose (1000 mg/kg body weight) of sucralose respectively by oral gavage. Doses were given once daily, six days a week for a total duration of 8 weeks. At the end of experiment, livers of all animal groups were observed for fatty change of cytoplasm. RESULTS: Artificial sweeteners cause cytoplasmic fatty change of varying degrees. This change was more marked in high dose group of aspartame (group III) as compared to low dose group (group II). In sucralose group, this change was seen only in high dose group (group V). CONCLUSION: Both artificial sweeteners-induced fatty changes in rat liver; the effect was least pronounced with low dose of sucralose.


Assuntos
Aspartame/farmacologia , Fígado/efeitos dos fármacos , Fígado/patologia , Sacarose/análogos & derivados , Edulcorantes/farmacologia , Animais , Citoplasma/efeitos dos fármacos , Citoplasma/patologia , Feminino , Hepatócitos/efeitos dos fármacos , Hepatócitos/patologia , Masculino , Ratos , Ratos Wistar , Sacarose/farmacologia
5.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 54(7): 456-462, 2019 Jul 09.
Artigo em Chinês | MEDLINE | ID: mdl-31288325

RESUMO

Objective: To study the influence of environmental factors on the two-species biofilm formed by the combinations of Streptococcus oligofermentans (So) with Streptococcus mutans (Sm) and Streptococcus sanguinis (Ss) with Sm so as to evaluate the role of So in maintaining the microecological balance of the oral cavity. Methods: Single-and two-species biofilms were grown on saliva-coated surfaces (glass tube and 96-well plate). Colony-counting method and safranin staining method were used to measure the biofilms formed under various oxygen conditions (aerobic and anaerobic), sucrose conditions (0%, 1% and 5% sucrose concentrations) and pH conditions (5.5, 6.0, 6.5, 7.0, 7.5 and 8.0). Results: Comparing the numbers of Sm in two co-cultures under various conditions, Sm counts in So+Sm group [(7.70±2.46)×10(8) CFU/ml] were significantly lower than those in Ss+Sm group [(9.00±1.13)×10(8) CFU/ml] in aerobic environment (P<0.05). Sm counts in So+Sm group [(2.80±0.52)×10(8) CFU/ml] were also significantly lower than those in the Ss+Sm group [(4.00±1.25)×10(8) CFU/ml] in anaerobic environment (P<0.05). The Sm counts in So+Sm group [(8.90±0.82)×10(8) CFU/ml] were significantly higher than those in Ss+Sm group [(7.50±1.73)×10(8) CFU/ml] in 0% sucrose environment (P<0.05). The Sm counts in So+Sm group [(5.70±2.94)×10(8) CFU/ml] were significantly lower than those in Ss+Sm group [(10.30±3.21) ×10(8) CFU/ml] in 1% sucrose environment (P<0.05). The Sm counts in So+Sm group [(6.10±1.71)×10(8) CFU/ml] were also significantly lower than those in Ss+Sm group [(7.40±1.20)×10(8) CFU/ml] in 5% sucrose environment (P<0.05). The Sm counts in So+Sm group [(3.50±1.50)×10(8) CFU/ml] were significantly lower than those in Ss+Sm group [(10.70±2.80)×10(8) CFU/ml] in pH7.0 environment (P<0.05). Comparing the formation of biofilm after 24 h cultivation, the Sm counts in So+Sm group were significantly lower than those in Ss+Sm group both in aerobic and anaerobic environments (P<0.05). The Sm counts in So+Sm group were significantly higher than those in Ss+Sm group in 0% sucrose environment (P<0.05). The Sm counts in So+Sm group were significantly lower than those in Ss+Sm group in 1% and 5% sucrose and pH 7.0 environments (P<0.05). Both So and Ss had no inhibitory effect on Sm in pH5.5 and pH8.0 environments. Conclusions: In the in vitro two-species co-culture systems, So showed stronger inhibitory effects than Ss on Sm and its inhibitory ability might influenced by various environmental factors.


Assuntos
Biofilmes , Meio Ambiente , Interações Microbianas , Boca , Streptococcus mutans , Streptococcus , Concentração de Íons de Hidrogênio , Interações Microbianas/fisiologia , Boca/microbiologia , Oxigênio/farmacologia , Saliva/microbiologia , Streptococcus/efeitos dos fármacos , Streptococcus mutans/efeitos dos fármacos , Streptococcus sanguis/efeitos dos fármacos , Sacarose/farmacologia
6.
J Basic Microbiol ; 59(9): 867-878, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31347180

RESUMO

Removal of heavy metals from food material by growing micro-organisms is limited by the toxicity to cells. In this study, different preincubation treatments were investigated to analyze their effects on cadmium resistance and removal ability of Pichia kudriavzevii A16 and Saccharomyces cerevisiae CICC1211. Sucrose preincubation improved the cadmium resistance of both yeast cells and increased the cadmium-removal rate of P. kudriavzevii A16. An evident decrease of intracellular and cell-surface cadmium accumulation was observed after sucrose preincubation, which may be the primary reason responsible for the improved cadmium resistance. Flow cytometry assay showed that sucrose significantly reduced the production of reactive oxygen species (ROS) and cell death rate of both yeasts under cadmium compared with those normally cultured cells. Under cadmium stress, the content of both protein carbonyls and malonyldialdehyde were also reduced by the addition of sucrose, the results were in accordance with the tendency of ROS, exhibiting a defending function of sucrose. Osmotic regulators as proline and trehalose were increased by sucrose preincubation in P. kudriavzevii A16 in the presence of cadmium. The results suggested that sucrose preincubation could be applied to improve cadmium resistance and removal rate of yeasts.


Assuntos
Cádmio/metabolismo , Pichia/efeitos dos fármacos , Pichia/metabolismo , Sacarose/farmacologia , Biodegradação Ambiental/efeitos dos fármacos , Cádmio/toxicidade , Viabilidade Microbiana/efeitos dos fármacos , Pichia/fisiologia , Prolina/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/fisiologia , Estresse Fisiológico/efeitos dos fármacos , Trealose/metabolismo
7.
Food Chem Toxicol ; 132: 110692, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31351100

RESUMO

Over the last two decades, safety concerns about low/no-calorie sweeteners (LNCS) have been described in the archival scientific literature including elevated risk of metabolic syndrome, type 2 diabetes, excessive weight gain, cardiovascular disease, safety, and disruption of the gut microbiome. A recent review by Lobach, Roberts, and Roland in Food and Chemical Toxicology examined 17 research articles on modulation of gut bacteria by LNCS along with other selected publications. In the conclusions of their paper, they claim that LNCS 1) do not affect gut microbiota at use levels and 2) are safe at levels approved by regulatory agencies. Both of these claims are incorrect. The scientific literature on LNCS clearly indicates that it is inappropriate to draw generalized conclusions regarding effects on gut microbiota and safety issues for compounds that vary widely chemical structure and pharmacokinetics. Scientific studies on the sweetener sucralose, used here as a representative LNCS, indicate that this organochlorine compound unequivocally and irrefutably disrupts the gut microbiome at doses relevant to human use. Results of dozens of additional research publications added and reviewed here also raise significant and extensive concerns about the safety of sucralose for the human food supply.


Assuntos
Microbioma Gastrointestinal/efeitos dos fármacos , Sacarose/análogos & derivados , Edulcorantes/farmacologia , Animais , Bactérias/classificação , Bactérias/isolamento & purificação , Contagem de Colônia Microbiana , Fezes/microbiologia , Humanos , Masculino , Ratos , Sacarose/administração & dosagem , Sacarose/efeitos adversos , Sacarose/farmacologia , Edulcorantes/administração & dosagem , Edulcorantes/efeitos adversos
8.
Pharmacol Biochem Behav ; 184: 172744, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31351907

RESUMO

Previous studies have shown that providing rats with a non-drug alternative in a choice situation can reduce ethanol taking in rats. There is also evidence that brief experience with non-drug reinforcers can reduce the reinforcing effects of drugs like cocaine, even when those non-drug alternatives are not pitted against the drug in a choice procedure. The goal of the present experiment was to determine whether experience with sucrose - a high value non-drug reinforcer in rats - in a non-choice situation would reduce ethanol's reinforcing effects, as measured within a behavioral economic framework. In a first phase, separate groups of rats worked on fixed-ratio schedules for ethanol, sucrose, or ethanol plus sucrose (during separate components within a session). In a second phase, all rats worked for ethanol and sucrose during alternating components. The introduction of sucrose components in the second phase to the group that previously only had experience with ethanol caused a significant decrease in ethanol self-administration. There was also a significant interaction whereby the effect of phase on the elasticity of demand for ethanol differed between the group that only had ethanol and the group that had ethanol plus sucrose in the first phase. These results indicate that a high value non-drug alternative reinforcer can reduce ethanol's reinforcing effects even when that alternative is not available at the time when ethanol is available. These findings suggest that treatments aiming to increase exposure to non-alcohol sources of reinforcement might be beneficial in reducing alcohol drinking.


Assuntos
Consumo de Bebidas Alcoólicas/psicologia , Etanol/administração & dosagem , Etanol/farmacologia , Esquema de Reforço , Análise de Variância , Animais , Comportamento Animal/efeitos dos fármacos , Condicionamento Operante/efeitos dos fármacos , Masculino , Motivação/efeitos dos fármacos , Ratos , Ratos Long-Evans , Autoadministração , Sacarose/administração & dosagem , Sacarose/farmacologia
9.
PLoS One ; 14(6): e0214170, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31206547

RESUMO

BACKGROUND: Current tools and strategies are not sufficient to reliably address threats and outbreaks of arboviruses including Zika, dengue, chikungunya, and yellow fever. Hence there is a growing public health challenge to identify the best new control tools to use against the vector Aedes aegypti. In this study, we investigated Ae. aegypti sugar feeding strategies in Bamako, Mali, to determine if this species can be controlled effectively using attractive toxic sugar baits (ATSB). METHODOLOGY: We determined the relative attraction of Ae. aegypti males and females to a variety of sugar sources including flowers, fruits, seedpods, and honeydew in the laboratory and using plant-baited traps in the field. Next, we observed the rhythm of blood feeding versus sugar feeding activity of Ae. aegypti in vegetation and in open areas. Finally, we studied the effectiveness of spraying vegetation with ATSB on Ae. aegypti in sugar rich (lush vegetation) and in sugar poor (sparse vegetation) urban environments. PRINCIPAL FINDINGS: Male and female laboratory sugar feeding rates within 24 h, on 8 of 16 plants offered were over 80%. The survival rates of mosquitoes on several plant sources were nearly as long as that of controls maintained on sucrose solution. In the field, females were highly attracted to 11 of 20 sugar sources, and 8 of these were attractive to males. Peak periods of host attraction for blood-feeding and sugar feeding in open areas were nearly identical and occurred shortly after sunrise and around sunset. In shaded areas, the first sugar-seeking peak occurred between 11:30 and 12:30 while the second was from 16:30 to 17:30. In a 50-day field trial, ATSB significantly reduced mean numbers of landing / biting female Ae. aegypti in the two types of vegetation. At sugar poor sites, the mean pre-treatment catch of 20.51 females on day 14 was reduced 70-fold to 0.29 on day 50. At sugar rich sites, the mean pre-treatment catch of 32.46 females on day 14 was reduced 10-fold to a mean of 3.20 females on day 50. CONCLUSIONS: This is the first study to show how the vector Ae. aegypti depends on environmental resources of sugar for feeding and survival. The demonstration that Ae. aegypti populations rapidly collapsed after ATSB treatment, in both sugar rich and sugar poor environments, is strong evidence that Ae. aegypti is sugar-feeding frequently. Indeed, this study clearly demonstrates that Ae. aegypti mosquitoes depend on natural sugar resources, and a promising new method for vector control, ATSB, can be highly effective in the fight against Aedes-transmitted diseases.


Assuntos
Aedes/metabolismo , Comportamento Alimentar , Inseticidas/farmacologia , Controle de Mosquitos/métodos , Sacarose/metabolismo , Animais , Vetores de Doenças , Feminino , Masculino , Mali , Sacarose/farmacologia , Infecção por Zika virus/prevenção & controle
10.
Behav Neurosci ; 133(4): 385-397, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31169385

RESUMO

The medial frontal cortex (MFC) is crucial for selecting actions and evaluating their outcomes. Outcome monitoring may be triggered by rostral parts of the MFC, which contain neurons that are modulated by reward consumption and are necessary for the expression of relative reward value. Here, we examined if the MFC further has a role in the control of instrumental licking. We used a progressive ratio licking task in which rats had to make increasing numbers of licks to receive liquid sucrose rewards. We determined what measures of progressive ratio performance are sensitive to value by testing rats with rewards containing 0%-16% sucrose. We found some measures (breakpoint, number of licking bouts) were sensitive to sucrose concentration and others (response rate, duration of licking bouts) were not. Then, we examined the effects of reversibly inactivating rostral (medial orbital) and caudal (prelimbic) parts of the MFC. We were surprised to find that inactivation had no effects on measures associated with value (e.g., breakpoint). Instead, inactivation altered behavioral measures associated with the pace of task performance (response rate and time to break). These effects depended on where inactivations were made. Response rates increased and time to break decreased when the caudal prelimbic area was inactivated. By contrast, response rates decreased and the time to break increased when the rostral medial orbital cortex was inactivated. Our findings suggest that the medial frontal cortex has a role in maintaining task engagement, but not in the motivational control of action, in the progressive ratio licking task. (PsycINFO Database Record (c) 2019 APA, all rights reserved).


Assuntos
Comportamento Animal/fisiologia , Lobo Frontal/fisiologia , Tempo de Reação/fisiologia , Animais , Feminino , Giro do Cíngulo/fisiologia , Masculino , Motivação , Neurônios/fisiologia , Córtex Pré-Frontal/fisiologia , Ratos , Ratos Long-Evans , Ratos Sprague-Dawley , Recompensa , Sacarose/farmacologia
11.
J Plant Physiol ; 238: 1-11, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31121522

RESUMO

Treatment of Arabidopsis thaliana seedlings with the PSII-inhibiting herbicide atrazine results in xenobiotic and oxidative stress, developmental arrest, induction of senescence and cell death processes. In contrast, exogenous sucrose supply confers a high level of atrazine stress tolerance, in relation with genome-wide modifications of transcript levels and regulation of genes involved in detoxification, defense and repair. However, the regulation mechanisms related to exogenous sucrose, involved in this sucrose-induced tolerance, are largely unknown. Characterization of these mechanisms was carried out through a combination of transcriptomic, metabolic, functional and mutant analysis under different conditions of atrazine exposure. Exogenous sucrose was found to differentially regulate genes involved in polyamine synthesis. ARGININE DECARBOXYLASE ADC1 and ADC2 paralogues, which encode the rate-limiting enzyme (EC 4.1.1.19) of the first step of polyamine biosynthesis, were strongly upregulated by sucrose treatment in the presence of atrazine. Such regulation occurred concomitantly with significant changes of major polyamines (putrescine, spermidine, spermine). Physiological characterization of a mutant affected in ADC activity and exogenous treatments with sucrose, putrescine, spermidine and spermine further showed that modification of polyamine synthesis and of polyamine levels could play adaptive roles in response to atrazine stress, and that putrescine and spermine had antagonistic effects, especially in the presence of sucrose. This interplay between sucrose, putrescine and spermine is discussed in relation with survival and anti-death mechanisms in the context of chemical stress exposure.


Assuntos
Arabidopsis/efeitos dos fármacos , Atrazina/farmacologia , Herbicidas/farmacologia , Putrescina/metabolismo , Espermidina/metabolismo , Espermina/metabolismo , Sacarose/farmacologia , Arabidopsis/metabolismo , Morte Celular/efeitos dos fármacos , Resistência a Herbicidas , Estresse Oxidativo/efeitos dos fármacos , Fotossíntese/efeitos dos fármacos , Complexo de Proteína do Fotossistema II/efeitos dos fármacos , Reação em Cadeia da Polimerase em Tempo Real , Plântula/efeitos dos fármacos , Plântula/metabolismo , Transcriptoma/efeitos dos fármacos
12.
Toxins (Basel) ; 11(5)2019 05 22.
Artigo em Inglês | MEDLINE | ID: mdl-31121925

RESUMO

Fusarium proliferatum can infect many crops and then produce fumonisins that are very harmful to humans and animals. Previous study indicates that carbon sources play important roles in regulating the fumonisin biosynthesis. Unfortunately, there is limited information on the effects of carbon starvation in comparison with the carbon sources present in the host of fumonisin production in F. proliferatum. Our results indicated that F. proliferatum cultivated in the Czapek's broth (CB) medium in the absence of sucrose could greatly induce production of fumonisin, while an additional supplementation of sucrose to the culture medium significantly reduced the fumonisin production. Furthermore, cellulose and hemicellulose, and polysaccharide extracted from banana peel, which replaced sucrose as the carbon source, can reduce the production of fumonisin by F. proliferatum. Further work showed that these genes related to the synthesis of fumonisin, such as FUM1 and FUM8, were significantly up-regulated in the culture medium in the absence of sucrose. Consistent with fumonisin production, the expressions of FUM gene cluster and ZFR1 gene decreased after the addition of sucrose. Moreover, these genes were also significantly down-regulated in the presence of cellulose, hemicellulose or polysaccharide extracted from peel. Altogether, our results suggested that fumonisin production was regulated in F. proliferatum in response to different carbon source conditions, and this regulation might be mainly via the transcriptional level. Future work on these expressions of the fumonisin biosynthesis-related genes is needed to further clarify the response under different carbon conditions during the infection of F. proliferatum on banana fruit hosts. The findings in this study will provide a new clue regarding the biological effect of the fumonisin production in response to environmental stress.


Assuntos
Fumonisinas/metabolismo , Fusarium/metabolismo , Carbono/metabolismo , Celulose/farmacologia , Fusarium/efeitos dos fármacos , Fusarium/genética , Fusarium/crescimento & desenvolvimento , Musa , Polissacarídeos/farmacologia , Sacarose/farmacologia
13.
PLoS One ; 14(5): e0216431, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31086418

RESUMO

Outbred rats display variable preferences for bittersweet solutions, expressed as preference or avoidance of high concentrations of artificial sweeteners over water. This may reflect individual differences in appetitive/aversive conflict processing that may have predictive validity for disorders of motivation. Here we use a homecage two-bottle choice procedure to examine the test/retest stability and between-tastant consistency in sucralose preference to determine the reliability of bittersweet taste preference. Sucralose is a non-caloric artificial sweetener that is preferred by some rats and avoided by others. We sought to determine whether sucralose preference is consistent with preference of sucrose/quinine solutions that have known sweet and bitter taste qualities, respectively. We give fluid restricted rats 45-minutes homecage access to water and ascending concentrations of sucralose (SUCRA; 0.0025-10mM) or a compound solution of sucrose (116mM) + quinine (0.002-2mM) (SQ). We use a within-subject counterbalanced design (SUCRA or SQ testing) to determine preference of each bittersweet solution relative to water. We observed individual variability in preference for SUCRA and SQ, such that some rats preferred bittersweet solutions over water (preferring) while other rats preferred water over bittersweet solutions (avoiding). Within tastant, this preference remained stable across repeated testing. Between solutions, SUCRA preference scores correlated with SQ scores, suggesting consistent taste conflict processing for both bittersweet solutions. Population level analyses confirmed that preference generalizes across bittersweet solutions, and that rats' preferences for bittersweet solutions relative to water are stable over time. The test/retest and between-tastant reliability of this taste conflict screening procedure support the potential utility of this model for exploring individual variability in appetitive/aversive conflict processes mediating motivated behavior.


Assuntos
Individualidade , Sacarose/análogos & derivados , Edulcorantes/farmacologia , Percepção Gustatória/fisiologia , Animais , Masculino , Ratos , Ratos Long-Evans , Sacarose/farmacologia
14.
PLoS Biol ; 17(5): e3000238, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-31071075

RESUMO

The high vector competence of mosquitoes is intrinsically linked to their reproductive strategy because females need a vertebrate blood meal to develop large batches of eggs. However, the molecular mechanisms and pathways regulating mosquito host-seeking behaviour are largely unknown. Here, we test whether host-seeking behaviour may be linked to the female's energy reserves, with low energy levels triggering the search for a nutrient-rich blood meal. Our results demonstrate that sugar feeding delays host-seeking behaviour in the invasive tiger mosquito Aedes albopictus, but the levels of energy reserves do not correlate with changes in host-seeking behaviour. Using tissue-specific gene expression analyses, we show for the first time, to our knowledge, that sugar feeding alone induces a transient up-regulation of several vitellogenesis-related genes in the female fat body, resembling the transcriptional response after a blood meal. Specifically, high expression levels of a vitellogenin gene (Vg-2) correlated with the lowest host-seeking activity of sugar-fed females. Knocking down the Vg-2 gene via RNA interference (RNAi) restored host-seeking behaviour in these females, firmly establishing that Vg-2 gene expression has a pivotal role in regulating host-seeking behaviour in young Ae. albopictus females. The identification of a molecular mechanism regulating host-seeking behaviour in mosquitoes could pave the way for novel vector control strategies aiming to reduce the biting activity of mosquitoes. From an evolutionary perspective, this is the first demonstration of vitellogenin genes controlling feeding-related behaviours in nonsocial insects, while vitellogenins are known to regulate caste-specific foraging and brood-care behaviours in eusocial insects. Hence, this work confirms the key role of vitellogenin in controlling feeding-related behaviours in distantly related insect orders, suggesting that this function could be more ubiquitous than previously thought.


Assuntos
Aedes/fisiologia , Corpo Adiposo/metabolismo , Comportamento de Busca por Hospedeiro , Vitelogeninas/metabolismo , Aedes/efeitos dos fármacos , Animais , Metabolismo Energético/efeitos dos fármacos , Corpo Adiposo/efeitos dos fármacos , Comportamento Alimentar/efeitos dos fármacos , Feminino , Especificidade de Órgãos/efeitos dos fármacos , Filogenia , Sacarose/farmacologia
15.
Poult Sci ; 98(9): 4161-4171, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31065720

RESUMO

Chicken semen conservation is an important tool for programs of genetic diversity management and of endangered breeds' conservation. However, the method still needs to be improved in order to be applied in a wide variety of environments and breeds. Our objective was to compare the effects of 2 external cryoprotectants saccharides (sucrose and raffinose) on the sperm freezability of a Thai local breed, Pradu Hang Dum, in which semen was frozen with a simple freezing method using nitrogen vapors and dimethyl formamide (DMF). Thirty-six males were selected on their motility vigor score for the experiments. In a first experiment, a large range of sucrose and raffinose doses were tested. Semen quality was evaluated after incubation at 5°C or after cryopreservation in straws in the saline Blumberger Hahnen Sperma Verdünner diluent + DMF (6% v/v) with or without sucrose/raffinose. The best targeted doses of sucrose and raffinose were then kept for experiment 2 that was focused on cryopreserved semen. In this experiment, semen quality was measured on frozen-thawed sperm: different objective motility data evaluated by computer-assisted sperm analysis (CASA), membrane integrity, acrosome integrity, mitochondria function evaluated using flow cytometry, lipid peroxide production assessed by the thiobarbituric acid test. Fertility obtained with frozen-thawed semen supplemented or not with sucrose or raffinose was also evaluated after artificial insemination of laying hens. The presence of sucrose at the osmotically inactive dose 1 mmol significantly increased the vigor motility, membrane integrity, acrosome integrity, and mitochondrial functions of frozen-thawed sperm (P < 0.05), and showed the highest levels of fertility after sperm cryopreservation (91% vs. control 86%, P < 0.001). Raffinose showed negative effects on in vitro semen quality from 1 to 100 mmol. Fertility was also negatively (P < 0.001) affected by raffinose (fertility rate 66 to 70%). We thus showed in the present study the high success of a simple chicken sperm cryopreservation method with an external cryoprotectant easily available and cheap, the sucrose, used at an osmotically inactive low concentration.


Assuntos
Galinhas/fisiologia , Crioprotetores/farmacologia , Fertilização/fisiologia , Rafinose/farmacologia , Preservação do Sêmen/veterinária , Espermatozoides/fisiologia , Sacarose/farmacologia , Animais , Feminino , Masculino , Análise do Sêmen/veterinária , Preservação do Sêmen/métodos
16.
Int J Food Sci Nutr ; 70(8): 970-976, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31066319

RESUMO

The study was designed to examine the immunomodulatory effect of three commercial sweeteners on human peripheral blood mononuclear cells (PBMC) and on the immune dialogue between these and human HT-29 and HuCC colon cancer lines. PBMC were incubated with Sweet'N Low, Splenda and Stevia and the cytokine production was examined. The cytokine release of PBMC co-cultured with colon cancer cells in the presence of sweeteners was evaluated. Sweet'N Low enhanced IFNγ, IL-1ß and IL-6 release, and augmented HuCC-induced IL-10 secretion. Splenda reduced IFNγ and TNFα secretion by LPS and HuCC stimulated PBMC and enhanced HuCC-induced IL-10 and IL-1ra production. Stevia reduced IL-1ß, TNFα and IL-1ra secretion prompted by HuCC and HT-29 cells and enhanced IL-6 production induced by HuCC. The inhibition of pro-inflammatory- and increased anti-inflammatory cytokines release by Splenda and Stevia indicate that they possess valuable potential as carcinopreventive agents.


Assuntos
Colo/efeitos dos fármacos , Colo/metabolismo , Neoplasias do Colo/metabolismo , Citocinas/metabolismo , Edulcorantes/farmacologia , Anti-Inflamatórios/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Técnicas de Cocultura , Células HT29 , Humanos , Interferon gama/metabolismo , Proteína Antagonista do Receptor de Interleucina 1/metabolismo , Interleucina-10/metabolismo , Interleucina-1beta/metabolismo , Interleucina-6/metabolismo , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/metabolismo , Stevia/metabolismo , Sacarose/análogos & derivados , Sacarose/farmacologia , Fator de Necrose Tumoral alfa/metabolismo
17.
Anim Reprod Sci ; 206: 69-77, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31138492

RESUMO

Sperm vitrification is a rapid freezing method in which carbohydrates are used as cryoprotectants. The aim of this study was to determine the optimal volume, concentration and type of carbohydrates for stallion sperm vitrification using 0.25 ml straws in comparison to conventional freezing. Ejaculates (n = 54) were collected from six stallions. For vitrification, straws were filled with different volumes (30, 70, 100 µl), sperm concentrations (50, 100, 200 × 106 sperm/ml) and extenders containing sucrose (20, 100, 200 mM), trehalose (50, 100, 200 mM) and raffinose (50, 100, 200 mM) and plunged into LN2. Conventional freezing was performed in 0.5 ml straws frozen in LN2 vapors. Sperm motility, plasma and acrosome membrane integrities and DNA fragmentation were compared among treatments. The use of straws filled with 100 µl at 100 × 106 sperm/ml with the extender containing 100 mM trehalose resulted in greater values for sperm quality than the other concentrations, volumes and carbohydrates. With vitrification, there were greater values (mean ± SEM; P < 0.05) than freezing for progressive motility (48.2 ± 2.3 compared with 37.3 ± 2.2%), plasma membrane integrity (82.8 ± 1.5 compared with 74.1 ± 1.9%), and intact acrosomes (50.2 ± 1.2 compared with 43.1 ± 1.4%); and less DNA fragmentation (6.4 ± 0.7 compared with 8.2 ± 0.3%). In conclusion, stallion sperm can be vitrified in 0.25 ml straws filled with 100 µl of sperm at 100 x 106 sperm/ml using an extender with 100 mM of trehalose, obtaining better sperm quality after warming than conventional freezing.


Assuntos
Carboidratos/farmacologia , Criopreservação/veterinária , Crioprotetores/farmacologia , Análise do Sêmen/veterinária , Preservação do Sêmen/veterinária , Motilidade Espermática , Vitrificação , Animais , Criopreservação/métodos , Cavalos , Masculino , Rafinose/farmacologia , Preservação do Sêmen/métodos , Sacarose/farmacologia , Edulcorantes/farmacologia , Trealose/farmacologia
18.
Drug Deliv ; 26(1): 532-541, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31090468

RESUMO

Oral drug delivery is an attractive noninvasive alternative to injectables. However, oral delivery of biopharmaceuticals is highly challenging due to low stability during transit in the gastrointestinal tract (GIT), resulting in low systemic bioavailability. Thus, novel formulation strategies are essential to overcome this challenge. An interesting approach is increasing retention in the GIT by utilizing mucoadhesive biomaterials as excipients. Here, we explored the potential of the GRAS excipient sucrose acetate isobutyrate (SAIB) to obtain mucoadhesion in vivo. Mucoadhesive properties of a 90% SAIB/10% EtOH (w/w) drug delivery system (DDS) were assessed using a biosimilar mucus model and evaluation of rheological behavior after immersion in biosimilar intestinal fluid. To ease readability of this manuscript, we will refer to this as SAIB DDS. The effect of SAIB DDS on cell viability and epithelial membrane integrity was tested in vitro prior to in vivo studies that were conducted using SPECT/CT imaging in rats. When combining SAIB DDS with biosimilar mucus, increased viscosity was observed due to secondary interactions between biosimilar mucus and sucrose ester predicting considerable mucoadhesion. Mucoadhesion was confirmed in vivo, as radiolabeled insulin entrapped in SAIB DDS, remained in the small intestine for up to 22 h after administration. Moreover, the integrity of the system was investigated using the dynamic gastric model under conditions simulating the chemical composition of stomach fluid and physical shear stress in the antrum under fasted conditions. In conclusion, SAIB is an interesting and safe biomaterial to promote high mucoadhesion in the GIT after oral administration.


Assuntos
Produtos Biológicos/administração & dosagem , Excipientes/farmacologia , Insulina/administração & dosagem , Sacarose/análogos & derivados , Adesivos Teciduais/farmacologia , Animais , Células CACO-2 , Sobrevivência Celular/efeitos dos fármacos , Liberação Controlada de Fármacos , Ácido Gástrico/química , Humanos , Masculino , Muco/química , Organização e Administração , Ratos Endogâmicos F344 , Reologia , Sacarose/farmacologia
19.
Mater Sci Eng C Mater Biol Appl ; 101: 404-414, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31029334

RESUMO

The synthesis of bioactive CuO/C nano composite using sucrose as a capping agent is achieved through simple green approach via Response Surface Methodology. The synthesis process was done in a green environment which prevents aggregation of sucrose and promotes nanoparticles formation. The innovative approach produces sucrose as a carbon source mediated copper oxide nanocomposites (CuO/C nanocomposite) with the particle size of 50 nm. Additionally, the produced CuO/C nanocomposite were characterized using microscopic techniques like SEM, TEM and spectroscopic techniques like UV-vis and X-ray diffraction. The antifungal activities of CuO/C nanocomposite were tested against Aspergillus niger and Aspergillus flavus species. At 1000 ppm of CuO/C nanocomposite, it showed 70% restraint on A. flavus and 90% hindrance on A. niger. The fungal inhibition mechanism of bioactive CuO/C nanocomposite was discussed in this research article. The particular high antifungal performance of CuO/C nanocomposite was found against Aspergillus niger while compare to Aspergillus flavus fungal strain.


Assuntos
Antifúngicos/farmacologia , Carbono/farmacologia , Cobre/farmacologia , Nanocompostos/química , Sacarose/farmacologia , Análise de Variância , Aspergillus/efeitos dos fármacos , Hemólise/efeitos dos fármacos , Humanos , Testes de Sensibilidade Microbiana , Nanocompostos/ultraestrutura , Análise de Regressão , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier
20.
Pharmacol Biochem Behav ; 181: 9-16, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30954637

RESUMO

Learning processes associated with nicotine influence the development of addiction to tobacco products. In the present report, we are interested in the interoceptive stimulus effects of nicotine acquiring control over appetitive behaviors - specifically, reward seeking. Also of interest is the current smoking cessation drug, varenicline (Chantix®). Varenicline, with its nicotine-like stimulus effects, can decrease withdrawal and cravings for a subset of individuals addicted to nicotine, though relapse is still common. We trained rats (N = 48) with nicotine (0.4 mg/kg, SC) as an excitatory stimulus (i.e., paired with sucrose) in a drug-discriminated goal-tracking (DGT) task. There was no access to sucrose on interspersed saline days. After acquisition of the initial nicotine-saline discrimination, rats were separated into four groups to test discrimination reversal and drug substitution. The control group maintained nicotine as the excitatory stimulus (NIC+). The substitution group had varenicline (1 mg/kg) replace nicotine as the stimulus paired with sucrose (VAR+). One reversal group had nicotine signal the absence of sucrose (i.e., now available on intermixed saline sessions; NIC-). The last group was similar to the NIC- group except varenicline replaced nicotine on non-reinforced sessions (VAR-). We found that varenicline fully substituted as the training stimulus when the drug-sucrose relation remained in place (VAR+). Both reversal groups acquired the new discrimination, albeit slowly and more variable for the VAR- group in comparison to NIC-. There was an effect of group during substitution testing. Specifically, nicotine fully substituted for varenicline regardless of condition. However, varenicline only partially substituted for the nicotine stimulus. At the start of extinction, responding mimicked that of the rats training condition. However, by extinction session 12, all groups maintained similarly low levels of responding. These findings show nicotine and varenicline share stimulus elements, yet the conclusion of partial to full substitution depends on the nature of the testing protocol.


Assuntos
Comportamento Apetitivo/efeitos dos fármacos , Interocepção/efeitos dos fármacos , Nicotina/farmacologia , Agonistas Nicotínicos/farmacologia , Vareniclina/farmacologia , Animais , Condicionamento Clássico/efeitos dos fármacos , Aprendizagem por Discriminação/efeitos dos fármacos , Substituição de Medicamentos , Extinção Psicológica/efeitos dos fármacos , Injeções Subcutâneas , Masculino , Nicotina/administração & dosagem , Agonistas Nicotínicos/administração & dosagem , Ratos , Ratos Sprague-Dawley , Solução Salina/farmacologia , Abandono do Hábito de Fumar , Síndrome de Abstinência a Substâncias/tratamento farmacológico , Sacarose/farmacologia , Vareniclina/administração & dosagem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA