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1.
J Sports Sci ; 38(2): 187-191, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31783721

RESUMO

The popularity of pre-workout supplements is rising amongst professional athletes and fitness enthusiasts. Despite increased usage, the safety profile of pre-workout supplements is likely to be not well understood. Additionally, many different brands use various undisclosed proprietary blends of active ingredients creating safety regulation difficulties. This lack of oversight could prove unsafe for certain patients. This patient MK is a 33-year-old healthy housewife who presented with central chest tightness, pre-syncope and mild dyspnoea to the emergency department via ambulance. The presentation was in the context of recent strenuous exercise and ingestion of a pre-workout supplement (Alpha Lean-7). Most striking in her presentation was a troponin rise of 50 ng/L, while not very high it is unusual given her lack of cardiac risk factors. She had a 3-day uneventful admission with a downtrending troponin prior to discharge. This case highlights the possible dangers of pharmacologically active ingredients in pre-workout supplements.


Assuntos
Suplementos Nutricionais/efeitos adversos , Isquemia Miocárdica/etiologia , Corrida/fisiologia , Adulto , Cafeína/efeitos adversos , Estimulantes do Sistema Nervoso Central/efeitos adversos , Dispneia/etiologia , Serviço Hospitalar de Emergência , Feminino , Produtos de Degradação da Fibrina e do Fibrinogênio/metabolismo , Humanos , Isquemia Miocárdica/sangue , Síncope/etiologia , Troponina/sangue
2.
Toxicol Lett ; 321: 122-130, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31874197

RESUMO

Our previous studies confirmed that prenatal caffeine exposure (PCE) could induce susceptibility to osteoarthritis in adult offspring rats due to poor chondrocyte differentiation, but its mechanism remains to be further investigated. This study aimed to explore whether subchondral bone dysplasia mediates susceptibility to osteoarthritis in adult offspring rats induced by PCE. Pregnant Wistar rats were treated with caffeine (120 mg/kg.d) or saline from gestational day (GD) 9 to 20. The female offspring were euthanized to collect femurs at GD20, postnatal week (PW) 6, and PW28 (non-ovariectomy and ovariectomy groups) to detect osteoarthritis-like phenotype, subchondral bone mass, ossification center development, and other evidence. The results showed that PCE increased the Mankin score of pathological articular cartilage, but decreased articular cartilage thickness and subchondral bone mass, which were more obvious after ovariectomy. Meanwhile, the correlation analysis results demonstrated that the Mankin score of articular cartilage was significantly negatively correlated with subchondral bone mass, and the thickness of articular cartilage was significantly positively correlated with subchondral bone mass. Further, the length and area of the primary and secondary ossification centers, the number of osteoblasts, and the related genes' expression of osteogenic differentiation (e.g., Runx2, BSP, ALP, and OCN) were all significantly decreased in the PCE group before and after birth. Taken together, PCE induced susceptibility to osteoarthritis in adult female offspring, which was likely related to the subchondral bone dysplasia and reduction of subchondral bone mass production due to developmental disorder of primary and secondary ossification centers caused by osteoblast differentiation disability before and after birth.


Assuntos
Doenças do Desenvolvimento Ósseo/induzido quimicamente , Cafeína/toxicidade , Cartilagem Articular/efeitos dos fármacos , Estimulantes do Sistema Nervoso Central/toxicidade , Osteoartrite/induzido quimicamente , Osteogênese/efeitos dos fármacos , Efeitos Tardios da Exposição Pré-Natal , Fatores Etários , Animais , Doenças do Desenvolvimento Ósseo/genética , Doenças do Desenvolvimento Ósseo/metabolismo , Doenças do Desenvolvimento Ósseo/patologia , Cartilagem Articular/patologia , Diferenciação Celular/efeitos dos fármacos , Feminino , Fêmur/efeitos dos fármacos , Fêmur/metabolismo , Fêmur/patologia , Idade Gestacional , Osteoartrite/genética , Osteoartrite/metabolismo , Osteoartrite/patologia , Osteoblastos/efeitos dos fármacos , Osteoblastos/metabolismo , Osteoblastos/patologia , Osteogênese/genética , Ovariectomia , Gravidez , Ratos Wistar , Fatores Sexuais , Tíbia/efeitos dos fármacos , Tíbia/metabolismo , Tíbia/patologia
3.
J Agric Food Chem ; 68(1): 323-331, 2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31880932

RESUMO

4G-α-Glucopyranosylrutin (monoglucosylrutin, MGR) is a flavonol glycoside with quercetin as an aglycone, is pale yellow in color, and engages in both copigmentation and anticopigmentation. In this study, we elucidated the mechanism underlying the copigmentation of MGR upon complexation with caffeine. Three approaches were used: binding analyses based on changes in the absorbance spectrum, NOESY experiments, and DFT and TDDFT calculations using an explicit solvation model. Our findings show that copigmentation mainly results from a bathochromic shift in the absorbance spectrum and not a from hyperchromic effect. MGR and caffeine form a complex in both 1:1 and 1:2 stoichiometric ratios. The calculated optimized 1:1 and 1:2 complex structures were supported by the NOESY spectrum and form a cluster with 13 and 11 water molecules, respectively, through hydrogen bonds. Although HOMO and LUMO contribute most to the excitation of both the MGR monomer and the complexes, these frontier molecular orbitals in the complexes are distributed more widely than those in the MGR monomer. In particular, LUMO in the complexes spreads into the copigment caffeine and the solvent water molecules. This increase in electron delocalization reduces the energy gap between the frontier molecular orbitals, resulting in copigmentation with a bathochromic shift.


Assuntos
Cafeína/química , Flavonóis/química , Glucosídeos/química , Cor , Ligações de Hidrogênio
4.
Braz J Med Biol Res ; 52(12): e9169, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31826183

RESUMO

We investigated the effect of caffeine ingestion combined with a 2-wk sprint interval training (SIT) on training-induced reductions in body adiposity. Twenty physically-active men ingested either 5 mg/kg of cellulose as a placebo (PLA, n=10) or 5 mg/kg of caffeine (CAF, n=10) 60 min before each SIT session (13×30 s sprint/15 s of rest). Body mass and skinfold thickness were measured pre- and post-training. Energy expenditure was measured at rest, during exercise, and 45 min after exercise in the first SIT session. Body fat was similar between PLA and CAF groups at pre-training (P>0.05). However, there was a significant decrease in body fat after training in the CAF group (-5.9±4.2%, P<0.05) but not in PLA (1.5±8.0%, P>0.05). There was no difference in energy expenditure at rest and during exercise between PLA and CAF groups (P>0.05), but the post-exercise energy expenditure was 18.3±21.4% greater in the CAF than in the PLA group (P<0.05). In conclusion, caffeine ingestion before SIT sessions induced a body fat loss that may be associated with higher post-exercise energy expenditure.


Assuntos
Tecido Adiposo/efeitos dos fármacos , Cafeína/administração & dosagem , Metabolismo Energético/efeitos dos fármacos , Treinamento Intervalado de Alta Intensidade , Consumo de Oxigênio/efeitos dos fármacos , Adulto , Método Duplo-Cego , Humanos , Masculino , Adulto Jovem
5.
Chin J Physiol ; 62(6): 279-284, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31793465

RESUMO

The aim of this study was to investigate the plasma dopamine and serum serotonin levels in humans with and without caffeine (CAFF) ingestion during treadmill running exercise. Thirty male volunteers participated in the randomized experiment involving two groups: CON (n = 15, 200 mL of tap water) versus CAFF (n = 15, 3 mg/kg CAFF and 200 mL tap water). After treadmill running, the dopamine level was significantly increased in the CAFF group (P < 0.01) and was significantly higher than in the CON group (P < 0.01). Serotonin was significantly increased in both groups after treadmill running (P < 0.05). However, serotonin levels showed no significant statistical difference between the groups. Prolactin and cortisol were significantly increased in both groups after treadmill running (P < 0.01). However, there was no significant statistical difference between groups. ß-endorphin level was significantly increased in the CAFF group at after treadmill running (P < 0.01) and was significantly higher than in CON after treadmill running (P < 0.01). In conclusion, 3 mg/kg CAFF ingestion before treadmill running stimulated dopamine release without inhibiting serotonin, which may reduce central fatigue.


Assuntos
Corrida , Cafeína , Dopamina , Teste de Esforço , Humanos , Masculino , Homens
6.
J Int Soc Sports Nutr ; 16(1): 56, 2019 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-31771598

RESUMO

BACKGROUND: A limited amount of research has demonstrated beneficial effects of caffeine and theanine supplementation for enhancement of mental performance. The purpose of this investigation was to determine whether the acute ingestion of a supplement containing caffeine, theanine and tyrosine improves mental and physical performance in athletes. METHODS: Twenty current or former male collegiate athletes (age: 20.5 ± 1.4 y; height: 1.82 ± 0.08 m; weight: 83.9 ± 12.6 kg; body fat: 13.8 ± 5.6%) completed this randomized, double-blind, placebo-controlled crossover trial. After familiarization, each participant completed two identical testing sessions with provision of a proprietary dietary supplement (SUP) containing caffeine theanine and tyrosine or a placebo (PL). Within each testing session, participants completed assessments of mental and physical performance before and after provision of SUP or PL, as well as after two rounds of exercise. Assessments were performed using a performance testing device (Makoto Arena) that evaluated multiple aspects of mental and physical performance in response to auditory and visual stimuli. Testing was performed both with the body in a static position and during dynamic movement. General linear models were used to evaluate the effects of SUP and PL on performance. RESULTS: Changes in movement accuracy during performance assessment were greater following SUP ingestion as compared to PL for both static and dynamic testing (SUP: + 0.4 to 7.5%; PL: - 1.4 to 1.4% on average; p < 0.05). For dynamic testing, the change in number of targets hit was higher and the change in average hit time was lower with SUP as compared to PL (p < 0.05). However, there were no differences between conditions for the changes in number of targets hit or average hit time during static testing. There were no differences in changes of subjective variables during either condition, and performance measures during the two rounds of exercise did not differ between conditions (p > 0.05). DISCUSSION: The present results indicate that a combination of a low-dose of caffeine with theanine and tyrosine may improve athletes' movement accuracy surrounding bouts of exhaustive exercise without altering subjective variables. Based on this finding, supplementation with caffeine, theanine and tyrosine could potentially hold ergogenic value for athletes in sports requiring rapid and accurate movements. TRIAL REGISTRATION: NCT03019523. Registered 24 January 2017.


Assuntos
Desempenho Atlético , Cafeína/farmacologia , Suplementos Nutricionais , Glutamatos/farmacologia , Substâncias para Melhoria do Desempenho/farmacologia , Tirosina/farmacologia , Estudos Cross-Over , Método Duplo-Cego , Humanos , Masculino , Adulto Jovem
7.
Pharm Res ; 36(12): 178, 2019 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-31701258

RESUMO

PURPOSE: The intracellular fraction of unbound compound (fu,cell) is an important parameter for accurate prediction of drug binding to intracellular targets. fu,cell is the result of a passive distribution process of drug molecules partitioning into cellular structures. Initial observations in our laboratory showed an up to 10-fold difference in the fu,cell of a given drug for different cell types. We hypothesized that these differences could be explained by the phospholipid (PL) composition of the cells, since the PL cell membrane is the major sink of unspecific drug binding. Therefore, we determined the fu,cell of 19 drugs in cell types of different origin. METHOD: The cells were characterized for their total PL content and we used mass spectrometric PL profiling to delineate the impact of each of the four major cellular PL subspecies: phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylserine (PS) and phosphatidylinositol (PI). The cell-based experiments were compared to cell-free experiments that used beads covered by PL bilayers consisting of the most abundant PL subspecies. RESULTS: PC was found to give the largest contribution to the drug binding. Improved correlations between the cell-based and cell-free assays were obtained when affinities to all four major PL subspecies were considered. Together, our data indicate that fu,cell is influenced by PL composition of cells. CONCLUSION: We conclude that cellular PL composition varies between cell types and that cell-specific mixtures of PLs can replace cellular assays for determination of fu,cell as a rapid, small-scale assay covering a broad dynamic range. Graphical Abstract.


Assuntos
Cafeína/química , Membrana Celular/metabolismo , Citoplasma/metabolismo , Fenazopiridina/química , Fosfolipídeos/metabolismo , Disponibilidade Biológica , Transporte Biológico , Linhagem Celular , Simulação por Computador , Interações de Medicamentos , Humanos , Modelos Biológicos
8.
World J Microbiol Biotechnol ; 35(12): 183, 2019 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-31728740

RESUMO

Caffeine is a naturally occurring alkaloid, where its major consumption occurs with beverages such as coffee, soft drinks and tea. Despite a variety of reports on the effects of caffeine on diverse organisms including yeast, the complex molecular basis of caffeine resistance and response has yet to be understood. In this study, a caffeine-hyperresistant and genetically stable Saccharomyces cerevisiae mutant was obtained for the first time by evolutionary engineering, using batch selection in the presence of gradually increased caffeine stress levels and without any mutagenesis of the initial population prior to selection. The selected mutant could resist up to 50 mM caffeine, a level, to our knowledge, that has not been reported for S. cerevisiae so far. The mutant was also resistant to the cell wall-damaging agent lyticase, and it showed cross-resistance against various compounds such as rapamycin, antimycin, coniferyl aldehyde and cycloheximide. Comparative transcriptomic analysis results revealed that the genes involved in the energy conservation and production pathways, and pleiotropic drug resistance were overexpressed. Whole genome re-sequencing identified single nucleotide polymorphisms in only three genes of the caffeine-hyperresistant mutant; PDR1, PDR5 and RIM8, which may play a potential role in caffeine-hyperresistance.


Assuntos
Cafeína/farmacologia , Farmacorresistência Fúngica/genética , Engenharia de Proteínas/métodos , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/genética , Transportadores de Cassetes de Ligação de ATP/genética , Acroleína/análogos & derivados , Acroleína/farmacologia , Antimicina A/análogos & derivados , Antimicina A/farmacologia , Proteínas de Ciclo Celular/genética , Cicloeximida/farmacologia , Proteínas de Ligação a DNA/genética , Mutagênese , Polimorfismo de Nucleotídeo Único , Proteínas de Saccharomyces cerevisiae/genética , Sirolimo/farmacologia , Estresse Fisiológico , Fatores de Transcrição/genética , Transcriptoma , Sequenciamento Completo do Genoma
9.
J Agric Food Chem ; 67(46): 12741-12751, 2019 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-31659899

RESUMO

Tyrosinase inhibitors are important in cosmetic, medical, and food industries due to their regulation of melanin production. A tyrosinase inhibitor was purified from Camellia pollen using high-speed countercurrent chromatography and preparative high-performance liquid chromatography and was identified as caffeine by NMR and mass spectrometry. It showed strong mushroom tyrosinase inhibitory activity with an IC50 of 18.5 ± 2.31 µg/mL in a noncompetitive model. The caffeine did not interact with copper ions in the active center of the enzyme but could quench fluorescence intensity and change the secondary conformation of this tyrosinase. A molecular dynamics simulation showed that caffeine bound this tyrosinase via Lys379, Lys 376, Asp357, Glu356, Thr308, Gln307, Asp312, and Trp358, thus changing the binding sites of l-tyrosine and the loop conformation adjacent to the active center. In vitro cell model analysis revealed that caffeine exhibited significant inhibitory effects on both intracellular tyrosinase activity and melanin production of B16-F10 melanoma cells in a concentration-dependent manner. These comprehensive results suggest that caffeine is a strong tyrosinase inhibitor that has the potential to be developed as skin-whitening agents in the cosmetics and pharmaceutical industries or as antibrowning agents in the food industry.


Assuntos
Cafeína/química , Camellia/química , Inibidores Enzimáticos/química , Monofenol Mono-Oxigenase/antagonistas & inibidores , Extratos Vegetais/química , Pólen/química , Animais , Cafeína/isolamento & purificação , Linhagem Celular , Cobre , Melaninas/biossíntese , Camundongos , Simulação de Dinâmica Molecular , Preparações Clareadoras de Pele/química
10.
J Int Soc Sports Nutr ; 16(1): 47, 2019 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-31660991

RESUMO

BACKGROUND: TeaCrine® is the synthetic version to naturally occurring theacrine (1, 3, 7, 9-tetramethyluric acid) found in the leaves of Camellia kucha tea plants. A few studies have examined the effects of TeaCrine® on cognitive perception, but no research exists examining its effects on resistance exercise performance. The purpose of this study was to determine the efficacy of TeaCrine®, a caffeine-like compound, on maximal muscular strength, endurance, and power performance in resistance-trained men. METHODS: Twelve resistance-trained men participated in a randomized, double-blind, cross-over designed study. Each participant performed one-repetition maximum (1RM) bench press, 1RM squat, bench press repetitions to failure (RTF) at 70% 1RM, squat RTF at 70% 1RM, and 2-km rowing time trial 90 min after consumption of: (1) Caffeine 300 mg (CAFF300); (2) TeaCrine® 300 mg (TEA300); (3) TeaCrine® + Caffeine (COMBO; 150 mg/150 mg); (4) Placebo 300 mg (PLA). Power and velocity were measured using a TENDO Power Analyzer. Visual analogue scales for energy, focus, motivation to exercise, and fatigue were administered at baseline and 90 min post-treatment ingestion (pre-workout). Rating of perceived exertion was assessed after bench press RTF and squat RTF. RESULTS: There were no differences between groups for 1RM, RTF, and power in the bench press and squat exercises. Only CAFF300 resulted in significant increases in perceived energy and motivation to exercise vs. TEA300 and PLA (Energy: + 9.8%, 95% confidence interval [3.3-16.4%], p < 0.01; + 15.3%, 95% CI [2.2-28.5%], p < 0.02; Motivation to exercise: + 8.9%, 95% CI [0.2-17.6%], p = 0.04, + 14.8%, 95% CI [4.7-24.8%], p < 0.01, respectively) and increased focus (+ 9.6%, 95% CI [2.1-17.1%], p = 0.01) vs. TEA300, but there were no significant differences between CAFF300 and COMBO (Energy + 3.9% [- 6.9-14.7%], Focus + 2.5% [- 6.3-11.3%], Motivation to exercise + 0.5% [- 11.6-12.6%]; p > 0.05). CONCLUSION: Neither TEA300, CAFF300, COMBO, or PLA (when consumed 90 min pre-exercise) improved muscular strength, power, or endurance performance in resistance-trained men. Only CAFF300 improved measures of focus, energy, and motivation to exercise.


Assuntos
Cafeína/farmacologia , Força Muscular/efeitos dos fármacos , Músculo Esquelético/efeitos dos fármacos , Substâncias para Melhoria do Desempenho/farmacologia , Resistência Física/efeitos dos fármacos , Ácido Úrico/análogos & derivados , Adulto , Estudos Cross-Over , Método Duplo-Cego , Humanos , Masculino , Treinamento de Resistência , Ácido Úrico/farmacologia , Adulto Jovem
11.
J Int Soc Sports Nutr ; 16(1): 44, 2019 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-31623659

RESUMO

BACKGROUND: The ergogenic properties of acute caffeine (CAF) and sodium bicarbonate (NaHCO3) ingestion on athletic performance have been previously investigated. However, each sport has unique physiological and technical characteristics which warrants optimizing supplementations strategies for maximizing performance. This study examined the effects of CAF and NaHCO3 ingestion on physiological responses and rate of perceived exertion during a Karate-specific aerobic test (KSAT) in competitive karatekas. METHODS: In a double-blind, crossover, randomized placebo-controlled trial, eight Karatekas underwent five experimental conditions including control (CON), placebo (PLA), CAF, NaHCO3, and CAF + NaHCO3 before completing KSAT. Capsules containing 6 mg/kg BW CAF were consumed 50 min prior to a KSAT whilst 0.3 g/kg BW NaHCO3 was consumed for 3 days leading to and 120, 90, and 60 min prior to a KSAT. Time to exhaustion (TTE), rate of perceived exertion (RPE), and blood lactate (BL) were measured before, immediately after and 3 min following KSAT. RESULTS: TTE was significantly greater following CAF, NaHCO3, and CAF + NaHCO3 consumption compared to PLA and CON. However, the differences between CAF, NaHCO3, and CAF + NaHCO3 were not statistically significant (p > 0.05). BL increased significantly from baseline to immediately after and 3 min following KSAT in all conditions (p < 0.01), while RPE at the end of KSAT was not significantly different between conditions (p = 0.11). CONCLUSIONS: Karate practitioners may benefit from the ergogenic effects of CAF and NaHCO3 when consumed separately or together.


Assuntos
Desempenho Atlético/fisiologia , Cafeína/farmacologia , Artes Marciais/fisiologia , Substâncias para Melhoria do Desempenho/farmacologia , Bicarbonato de Sódio/farmacologia , Adolescente , Estudos Cross-Over , Método Duplo-Cego , Humanos , Adulto Jovem
12.
J Sports Med Phys Fitness ; 59(9): 1435-1441, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31610637

RESUMO

BACKGROUND: This study investigated the effects of coffee ingestion with supplemental caffeine (CAF) on serum testosterone (T) responses to exercise in recreationally strength-trained males. METHODS: Subjects ingested 6 mg/kg body weight of caffeine via 12 ounces of coffee (CAF) supplemented with anhydrous caffeine or decaffeinated (DEC) coffee prior to exercise in a randomized, within-subject, crossover design. The exercise session consisted of 21 minutes of high-intensity interval cycling (alternating intensities at power outputs associated with 2.0 mmol/L lactate for two minutes and 4.0 mmol/L lactate for one minute) followed by resistance exercise (seven exercises, three sets of ten repetitions, 65% 1RM, one-minute rest periods). Subjects also completed repetitions to fatigue tests and soreness scales to determine muscle recovery 24 hours following the exercise. RESULTS: T was elevated immediately and 30-minutes post-exercise by 20.5% and 14.3% respectively (P<0.05). There was no main effect for treatment and no exercise x treatment interaction. There were no differences in repetitions to fatigue or soreness between treatments (P>0.05). No relationships were observed between T and any proxy of recovery. CONCLUSIONS: While past literature suggests caffeine may enhance T post-exercise, data from the current study suggest that augmented T response is not evident following anhydrous caffeine added to coffee. The duration of T elevation indicates that this protocol is beneficial to creating long-lasting increases in serum testosterone.


Assuntos
Cafeína/metabolismo , Treinamento Intervalado de Alta Intensidade/métodos , Treinamento de Resistência/métodos , Testosterona/sangue , Adulto , Cafeína/administração & dosagem , Café , Estudos Cross-Over , Humanos , Ácido Láctico/sangue , Masculino , Adulto Jovem
13.
Phys Chem Chem Phys ; 21(39): 22067-22080, 2019 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-31565708

RESUMO

The aggregation and deposition of neurotoxic Aß fibrils are key in the etiology of Alzheimer's disease (AD). It has been clinically recognized as a major form of dementia across the globe. Finding and testing various natural compounds to target Aß fibrils to disrupt their stable structures seems to be a promising and attractive therapeutic strategy. The destabilization effects of caffeine on Aß fibrils are investigated via in silico studies, where a series of molecular dynamics (MD) simulations, each of 100 ns, was conducted. The simulation outcomes obtained henceforth clearly indicated the drift of the terminal chains from the protofibrils, leading to disorganization of the characteristically organized cross-ß structures of Aß fibrils. The structural instability of Aß17-42 protofibrils is explained through enhanced fluctuations in the RMSD, radius of gyration and RMSF values in the presence of caffeine. The key interactions providing stability, comprising D23-K28 salt bridges, intra- and inter-chain hydrogen bonding and hydrophobic interactions involving interchain A21-V36 and F19-G38 and intrachain L34-V36, were found to be disrupted due to increases in the distances between the participating components. The loss of ß-sheet structure with the introduction of turns and α-helices in terminal chains may further inhibit the formation of higher order aggregates, which is necessary to stop the progression of the disease. The atomistic details obtained via MD studies relating to the mechanism behind the underlying destabilization of Aß17-42 protofibrils by caffeine encourage further investigations exploring the potency of natural compounds to treat AD via disrupting preformed neurotoxic Aß protofibrils.


Assuntos
Peptídeos beta-Amiloides/química , Produtos Biológicos/química , Cafeína/química , Simulação de Dinâmica Molecular , Sítios de Ligação , Ligações de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Ligação Proteica , Conformação Proteica , Estabilidade Proteica/efeitos dos fármacos , Termodinâmica , Água/química
14.
Anticancer Res ; 39(9): 4653-4657, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31519563

RESUMO

BACKGROUND/AIM: Osteosarcoma is a recalcitrant neoplasm which occurs predominantly in adolescents and young adults. Recently, using a patient-derived orthotopic xenograft (PDOX) model of malignant soft-tissue sarcoma (STS), we showed that oral recombinant methioninase (o-rMETase), in combination with caffeine, was more efficacious than o-rMETase alone in inhibiting STS tumor growth. In the present report, we determined the efficacy of o-rMETase combined with oral caffeine on a cisplatinum (CDDP)-resistant osteosarcoma PDOX model. MATERIALS AND METHODS: Osteosarcoma PDOX models were randomly divided into seven treatment groups (6 mice in each group): untreated control; CDDP alone; o-rMETase alone; o-rMETase with caffeine; CDDP plus o-rMETase; CDDP plus caffeine; and CDDP plus o-rMETase with caffeine. Tumor size and body weight were measured throughout the treatment. RESULTS: Tumors regressed after treatment with CDDP plus o-rMETase with caffeine. Tumors treated with CDDP plus o-rMETase with caffeine also had the most necrosis. CONCLUSION: The combination of o-rMETase and caffeine together with first-line chemotherapy was efficacious for drug-resistant osteosarcoma and has clinical potential in the treatment of this highly-resistant neoplasm.


Assuntos
Antimetabólitos Antineoplásicos/administração & dosagem , Cafeína/administração & dosagem , Liases de Carbono-Enxofre/administração & dosagem , Cisplatino/administração & dosagem , Resistencia a Medicamentos Antineoplásicos , Administração Oral , Animais , Modelos Animais de Doenças , Humanos , Camundongos , Osteossarcoma/diagnóstico por imagem , Osteossarcoma/tratamento farmacológico , Osteossarcoma/patologia , Carga Tumoral/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
15.
Endocrinology ; 160(10): 2314-2325, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31504387

RESUMO

Adaptive thermogenesis is a catabolic process that consumes energy-storing molecules and expends that energy as heat in response to environmental changes. This process occurs primarily in brown and beige adipose tissue. Thermogenesis is regulated by many factors, including lipid derived paracrine and endocrine hormones called lipokines. Recently, technologic advances for identifying new lipid biomarkers of thermogenic activity have shed light on a diverse set of lipokines that act through different pathways to regulate energy expenditure. In this review, we highlight a few examples of lipokines that regulate thermogenesis. The biosynthesis, regulation, and effects of the thermogenic lipokines in several families are reviewed, including oloeylethanolamine, endocannabinoids, prostaglandin E2, and 12,13-diHOME. These thermogenic lipokines present potential therapeutic targets to combat states of excess energy storage, such as obesity and related metabolic disorders.


Assuntos
Adaptação Fisiológica/fisiologia , Benzofuranos/metabolismo , Cafeína/metabolismo , Di-Iodotironinas/metabolismo , Fenilpropanolamina/metabolismo , Termogênese/fisiologia , Ioimbina/metabolismo , Animais
16.
Environ Sci Pollut Res Int ; 26(32): 33440-33450, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31522398

RESUMO

Investigation during 11-month period was performed to study the presence of caffeine in the Lis River in Leiria Town in Portugal, and a monitoring during 9-month period was realized to check the contribution of the human pollution of two wastewater treatment plants (WWTPs) that discharge their effluents to the studied river. The samples were collected in five sampling points along the river and in two influents and two effluents of the studied WWTPs. Caffeine was detected in all ninety-one collected samples. The caffeine concentration ranged from 25.3 to 321 ng/L in the river samples, from 112 to 1927 ng/L in the WWTP effluents, and from 9478 to 83,901 ng/L in the WWTP influents. The highest concentration in the river was detected in the two sampling points located after the effluent discharge points and reached 315 and 321 ng/L. Risk assessment was performed for three trophic levels using the risk quotient calculation and revealed that caffeine do not cause toxic effect on Daphnia magna and on fish but could be possibly toxic to algae. The results proved that caffeine can be an effective indicator of human-born pollution.


Assuntos
Cafeína/análise , Monitoramento Ambiental/métodos , Águas Residuárias/química , Poluentes Químicos da Água/análise , Cafeína/química , Cidades , Humanos , Portugal , Medição de Risco , Rios/química , Inquéritos e Questionários , Eliminação de Resíduos Líquidos , Águas Residuárias/análise
17.
Artigo em Inglês | MEDLINE | ID: mdl-31479386

RESUMO

A rapid method for quantitative caffeine analysis in carbonated and non-carbonated beverages and liquid dietary supplement products was developed based on the direct sample introduction technique of laser diode thermal desorption atmospheric pressure chemical ionisation with tandem mass spectrometry (LDTD-MS/MS). Product samples were diluted with a mixture of methanol, water, and d3-caffeine internal standard. Sample aliquots were filtered, spotted on a metal-lined LDTD microtitre plate, dried, and thermally desorbed for subsequent ionisation and analysis by MS/MS analysis. Each sample required a 6 s desorption, and sample-to-sample analysis time of less than 30 s per sample. Caffeine yielded a linear calibration curve over the range 0.5-100 µg mL-1 (R2 > 0.995). Caffeine recoveries from fortified samples ranged from 97% to 107% with <5% RSD. The caffeine determination was not affected by matrix interferences despite the large range of ingredients, vitamins, sweeteners, extracts, and additives present in the products tested, even though LDTD-MS/MS is a whole-sample desorption technique with no separation of matrix background. The method detection limit was below 0.12 µg mL-1. The method was applied to 33 caffeinated products and LDTD-MS/MS quantitative results closely correlated (R2 > 0.998) with the regulatory standard HPLC-UV method (AOAC Official Method 979.08).


Assuntos
Bebidas/análise , Cafeína/análise , Análise de Alimentos/métodos , Lasers , Análise de Alimentos/instrumentação , Espectrometria de Massas em Tandem
18.
J Int Soc Sports Nutr ; 16(1): 38, 2019 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-31488190

RESUMO

BACKGROUND: Caffeine (CAF) supplementation could have a positive impact on physical performance and sport abilities. Nevertheless, the CAF-induced, dose-dependent influence on discipline-specific performance and combat activity in combat sports have not been sufficiently investigated. The aim of this study was to examine the effect of single ingestion of 3, 6, or 9 mg/kg body weight of CAF and placebo (PLA) on judo-specific performance and sparring combat activities. METHODS: In a randomised double-blind placebo-controlled cross-over design, acute pre-exercise supplementation with CAF (3, 6, or 9 mg/kg body weight) and placebo PLA in 22 male highly-trained judoists was examined. The study protocol involved five separate testing sessions using the Special Judo Fitness Test (SJFT) with heart rate monitoring, three judo sparring combats and evaluation of the rate of perceived exertion (RPE) using the Borg scale. RESULTS: Six and 9 mg/kg CAF improved SJFT performance, while 9 mg/kg increased combat activity. Three mg/kg CAF lacked any apparent positive ergogenic effect. Among athletes, who include CAF-containing products in their habitual diet (consumers), only 9 mg/kg CAF effectively enhanced SJFT performance, while in those who do not consume CAF-containing products at regular basis (non-consumers), the enhancing effect was achieved even at 6 mg/kg. CONCLUSIONS: Regarding combat sports, higher (6-9 mg/kg) than currently recommended CAF dosages (3-6 mg/kg) are apparently more effective in terms of judo-specific performance. However, the ergogenic CAF effect is not only dose-dependent, but it is also related to customary CAF consumption. TRIAL REGISTRATION: Clinical Trials Gov, NCT03822663 . Registered 28 January 2019 - Retrospectively registered.


Assuntos
Desempenho Atlético/fisiologia , Cafeína/farmacologia , Artes Marciais/fisiologia , Substâncias para Melhoria do Desempenho/farmacologia , Adolescente , Adulto , Cafeína/administração & dosagem , Estudos Cross-Over , Relação Dose-Resposta a Droga , Método Duplo-Cego , Teste de Esforço , Humanos , Masculino , Substâncias para Melhoria do Desempenho/administração & dosagem , Adulto Jovem
19.
Molecules ; 24(17)2019 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-31480657

RESUMO

Alnustone, a nonphenolic diarylheptanoid, first isolated from Alnus pendula (Betulaceae), has recently received a great deal of attention due to its various beneficial pharmacological effects. However, its pharmacokinetic profile in vivo remains unclear. The purpose of this study is to establish a fast and sensitive quantification method of alnustone using liquid chromatography tandem mass spectrometry (LC-MS/MS) and evaluate the pharmacokinetic and tissue distribution profiles of alnustone in rats. The sample was precipitated with acetonitrile with 0.5% formic acid and separated on BEH C18 Column. The mobile phase was composed of 0.1% formic acid in water and methanol at a flow rate of 0.3 mL/min. Alnustone and the internal standard (caffeine) were quantitatively monitored with precursor-to-product ion transitions of m/z 262.9→105.2 and m/z 195.2→138.0, respectively. The calibration curve for alnustone was linear from 1 to 2000 ng/mL. The intra- and inter-day assay precision (RSD) ranged from 1.1-9.0 % to 3.3-8.6%, respectively and the intra- and inter-day assay accuracy (RE) was between -8.2-9.7% and -10.3-9.9%, respectively. The validated method was successfully applied to the pharmacokinetic studies of alnustone in rats. After single-dose intravenous administration of alnustone (5 mg/kg), the mean peak plasma concentration (Cmax) value was 7066.36 ± 820.62 ng/mL, and the mean area under the concentration-time curve (AUC0-t) value was 6009.79 ± 567.30 ng/mL∙h. Our results demonstrated that the residence time of alnustone in vivo was not long and it eliminated quickly from the rat plasma. Meanwhile, the drug is mainly distributed in tissues with large blood flow, and the lung and liver might be the target organs for alnustone efficacy. The study will provide information for further application of alnustone.


Assuntos
Cromatografia Líquida/métodos , Diarileptanoides/administração & dosagem , Diarileptanoides/farmacocinética , Espectrometria de Massas em Tandem/métodos , Administração Intravenosa , Animais , Cafeína/química , Calibragem , Diarileptanoides/sangue , Diarileptanoides/química , Limite de Detecção , Masculino , Ratos Sprague-Dawley , Padrões de Referência , Reprodutibilidade dos Testes , Distribuição Tecidual
20.
J Int Soc Sports Nutr ; 16(1): 37, 2019 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-31477133

RESUMO

The timing of macronutrient ingestion in relation to exercise is a purported strategy to augment muscle accretion, muscle and athletic performance, and recovery. To date, the majority of macronutrient nutrient timing research has focused on carbohydrate and protein intake. However, emerging research suggests that the strategic ingestion of various ergogenic aids and micronutrients may also have beneficial effects. Therefore, the purpose of this narrative review is to critically evaluate and summarize the available literature examining the timing of ergogenic aids (caffeine, creatine, nitrates, sodium bicarbonate, beta-alanine) and micronutrients (iron, calcium) on muscle adaptations and exercise performance. In summary, preliminary data is available to indicate the timing of caffeine, nitrates, and creatine monohydrate may impact outcomes such as exercise performance, strength gains and other exercise training adaptations. Furthermore, data is available to suggest that timing the administration of beta-alanine and sodium bicarbonate may help to minimize known untoward adverse events while maintaining potential ergogenic outcomes. Finally, limited data indicates that timed ingestion of calcium and iron may help with the uptake and metabolism of these nutrients. While encouraging, much more research is needed to better understand how timed administration of these nutrients and others may impact performance, health, or other exercise training outcomes.


Assuntos
Desempenho Atlético/fisiologia , Exercício , Micronutrientes/administração & dosagem , Substâncias para Melhoria do Desempenho/administração & dosagem , Fenômenos Fisiológicos da Nutrição Esportiva , Cafeína/administração & dosagem , Cálcio na Dieta/administração & dosagem , Creatina/administração & dosagem , Humanos , Ferro/administração & dosagem , Nitratos/administração & dosagem , Bicarbonato de Sódio/administração & dosagem , Fatores de Tempo , beta-Alanina/administração & dosagem
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