Periódicos
URI permanente desta comunidadehttps://thoth.dti.ufv.br/handle/123456789/3352
Navegar
35 resultados
Filtros
Configurações
Resultados da Pesquisa
Item Effects of caffeine on central and peripheral fatigue following closed- and open-loop cycling exercises(Associação Brasileira de Divulgação Científica, 2022-02-28) Couto, P. G.; Silva-Cavalcante, M. D.; Mezêncio, B.; Azevedo, R. A.; Cruz, R.; Bertuzzi, R.; Lima-Silva, A. E.; Kiss, M. A. P. D.We examined whether endurance performance and neuromuscular fatigue would be affected by caffeine ingestion during closed- and open-loop exercises. Nine cyclists performed a closed-loop (4,000-m cycling time trial) and an open-loop exercise (work rate fixed at mean power of the closed-loop trial) 60 min after ingesting caffeine (CAF, 5 mg/kg) or placebo (PLA, cellulose). Central and peripheral fatigue was quantified via pre- to post-exercise decrease in quadriceps voluntary activation and potentiated twitch force, respectively. Test sensitivity for detecting caffeine-induced improvements in exercise performance was calculated as the mean change in time divided by the error of measurement. Caffeine ingestion reduced the time of the closed-loop trial (PLA: 375.1±14.5 s vs CAF: 368.2±14.9 s, P=0.024) and increased exercise tolerance during the open-loop trial (PLA: 418.2±99.5 s vs CAF: 552.5±106.5 s, P=0.001), with similar calculated sensitivity indices (1.5, 90%CI: 0.7-2.9 vs 2.8, 90%CI: 1.9-5.1). The reduction in voluntary activation was more pronounced (P=0.019) in open- (-6.8±8.3%) than in closed-loop exercises (-1.9±4.4%), but there was no difference between open- and closed-loop exercises for the potentiated twitch force reduction (-25.6±12.8 vs -26.6±12.0%, P>0.05). Caffeine had no effect on central and peripheral fatigue development in either mode of exercise. In conclusion, caffeine improved endurance performance in both modes of exercise without influence on post-exercise central and peripheral fatigue, with the open-loop exercise imposing a greater challenge to central fatigue tolerance.Item Color stability and gloss of esthetic restorative materials after chemical challenges(Fundação Odontológica de Ribeirão Preto, 2019-03-11) Ozera, Eduardo Haruki; Pascon, Fernanda Miori; Correr, Américo Bortolazzo; Puppin-Rontani, Regina Maria; Castilho, Aline Rogéria de; Correr-Sobrinho, Lourenço; Paula, Andreia Bolzan deThis study evaluated gloss and color changes of esthetic restorative materials subjected to different acidic beverages. Specimens of resin composites (Z350XT (Z350), IPS Empress Direct (ED), Charisma Diamond (CD)) were prepared and the initial surface gloss and color (ΔE) were measured (n=10). Then, the specimens were immersed in 4 mL of each of the different beverages (cranberry juice; Coca-Cola; coffee or artificial saliva) during 15 min, 3x/day for 14 days and new gloss and color readings were obtained. Color change was evaluated with the ΔE formula and gloss change values were obtained by the formula: (final gloss - initial gloss). Data was submitted to two-way ANOVA followed by Tukey’s post hoc test (a=0.05). CD showed the lowest color change among resin composites. The highest ΔE values were obtained after immersion in coffee and cranberry juice. Coffee promoted the highest gloss change (worst gloss retention), followed by cranberry juice, Coca-cola and artificial saliva (p<0.05). The type of beverage significantly influenced the gloss of resin composites. Coca-cola reduced gloss of the three resin composites in a similar manner. Coffee affected the ED gloss more than that of Z350 and CD, while cranberry juice affected Z350 more than ED and CD. Saliva had a more pronounced effect on the gloss retention of CD than ED. The beverages used in this study influenced the optical surface properties of the composites studied.Item Green coffee extract attenuates Parkinson’s-related behaviors in animal models(Academia Brasileira de Ciências, 2021-11-01) Molska, Graziella R.; Paula-Freire, Lyvia Izaura G.; Sakalem, Marna E.; Köhn, Daniele O.; Negri, Giuseppina; Carlini, Elisaldo A.; Mendes, Fúlvio R.Epidemiological studies have shown an inverse association between coffee consumption and the development of Parkinson’s disease (PD). The effects of the oral treatment with green (non-roasted) coffee extracts (CE, 100 or 400 mg/kg) and caffeine (31.2 mg/kg) were evaluated on catalepsy induced by haloperidol in mice, and unilateral 6-OHDA lesion of medial forebrain bundle (MFB) or striatum in rats. Also, the in vitro antioxidant activity and the monoamine levels in the striatum were investigated. CE presented a mild antioxidant activity in vitro and its administration decreased the catalepsy index. CE at the dose of 400 mg/kg induced ipsilateral rotations 14 days after lesion; however, chronic 30-day CE and caffeine treatments did not interfere with the animals’ rotation after apomorphine or methamphetamine challenges in animals with MFB lesion, nor on monoamines levels. Furthermore, CE and caffeine were effective in inhibiting the asymmetry between ipsilateral and contralateral rotations induced by methamphetamine and apomorphine in animals with lesion in the striatum but did not avoid the monoamines depletion. These results indicate that CE components indirectly modulate dopaminergic transmission, suggesting a pro-dopaminergic action of CE, and further investigation must be conducted to elucidate the mechanisms of action and the possible neuroprotective role in PD.Item Plant stem cell extract from Coffea canephora shows antioxidant, anti-inflammatory, and skin regenerative properties mediated by suppression of nuclear factor-κB(Associação Brasileira de Divulgação Científica, 2023-06-30) Guidoni, M.; Sousa Júnior, A.D. de; Aragão, V.P.M.; Silva, M.V. Toledo e; Barth, T.; Clarindo, W.R.; Endringer, D.C.; Fronza, M.Plant cell cultures have become a promising production platform of bioactive compounds for biomedical and cosmetic uses in the last decades. However, the success so far has been limited. The study aimed to evaluate the effectiveness of this unique biotechnology process to obtain a bioactive stem cell extract of Coffea canephora (SCECC) with antioxidant, anti-inflammatory, and regenerative properties. Total phenolic and flavonoid contents were determined in the SCECC by spectrophotometry. The chemical composition of the extracts was characterized by mass spectrometry. Antioxidant activity was evaluated using the colorimetric methods of free radical scavenging 2,2'-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and the ferric reducing ability of plasma (FRAP). The anti-inflammatory activity was determined in lipopolysaccharide-stimulated RAW 264.7 macrophages through the production of superoxide anion (O2•-), nitric oxide (NO), tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and the activity of nuclear factor kappa B (NF-κB). Moreover, the ability of SCECC to stimulate the proliferation and migration of fibroblasts was assessed. Five compounds were tentatively identified, two flavonoids, two phenolic acids, and one sugar. High phenolic content and antioxidant activity were observed in the SCECC. SCECC promoted the proliferation and migration of fibroblasts and suppressed the pro-inflammatory mediators O2•-, NO, TNF-α, and IL-6 in a dose-dependent manner. Moreover, SCECC inhibited the NF-κB transcription factor. Therefore, we obtained evidence that the extract from C. canephora stem cells can be used as a natural agent against skin damage. Hence, it could be of interest in cosmetics for preventing skin aging.Item Bioactive compounds, antioxidant activity, physical and sensory characteristics of Mırra coffee(Sociedade Brasileira de Ciência e Tecnologia de Alimentos, 2022-03-18) Yalçinkaya, Cihan; Abdalla, Hassan Sarbaz; Bakkalbasi, EmreMırra is a coffee beverage widely consumed in Syria and Turkey, and often produced from roasted and ground coffee beans. Recently, it is prepared from classical instant coffee. In this study, some physicochemical, bioactive and sensory properties of Mırra samples were determined. The average viscosity, °Brix, HMF, total phenolic content, DPPH and ABTS values were 1.36 cP, 3.70, 71.60 mg/L, 3431.55 mg GA eq./L, 6.24 mmol Trol. eq./mL and 35.23 mmol Trol. eq./mL for Mırra samples made by traditional process, and 4.85 cP, 16.36, 303.3 mg/L, 11276.47 mg GA eq./L, 23.89 mmol Trol. eq./mL and 89.70 mmol Trol. eq./mL for Mırra samples made with classic instant coffee, respectively. All Mırra samples also contained high levels of caffeine (1416.93 - 4347.46 mg/L). Chlorogenic acid, 4-O-caffeoylquinic acid and trans-5-O-caffeoylquinic acid were identified in Mırra samples. Total chlorogenic acid contents of Mırra samples were ranged from 1097.85 to 5283.21 mg/L. In all sensory parameters, Mırras with °Brix value over 5.75 had high scores. Results show that Mırra has high antioxidant activity. However, Mırra consumption may have negative health effects for risk groups due to the high caffeine content.Item Phenolic compounds profile, neuroprotective effect and antioxidant potential of a commercial Turkish coffee(Pontifícia Universidade Católica de Campinas, 2020) Ayvaz, Melek ÇolThe purpose of this study is to determine the phenolic and flavonoid contents, and antioxidant activities and neuroprotective effects of powdered coffee sample of a commercial coffee brand originated from Sivas, Turkey.Item Acute caffeine intake lowers glycemia before and after acute physical exercise in diabetic rats(Pontifícia Universidade Católica de Campinas, 2014) Silva, Luiz Augusto da; Pereira, Ricardo Aparecido; Túrmina, Janaína Angela; Kerppers, Ivo Ilvan; Altimari, Leandro Ricardo; Malfatti, Carlos Ricardo ManeckThe present study investigated the effects of caffeine supplementation combined with acute physical exercise on the glycemic response of diabetic rats.Item Calcium and caffeine interaction in increased calcium balance in ovariectomized rats(Pontifícia Universidade Católica de Campinas, 2013) Silva, Sandra Tavares da; Costa, Neuza Maria Brunoro; Franco, Frederico Souzalima Caldoncelli; Natali, Antônio JoséThis study investigated the effects of caffeine intake associated with inadequate or adequate calcium intake in laparotomized or ovariectomized rats by means of the calcium balance. Forty adults Wistar rats were ovariectomized or laparotomized.Item Consumo de café segundo métodos de preparo da bebida e associação com perfil lipídico sérico em hipertensos e diabéticos(Pontifícia Universidade Católica de Campinas, 2011) Lima, Fabiana Accioly de; Vasconcelos, Sandra Mary Lima; Sant'ana, Antônio Euzébio Goulart; Ataíde, Terezinha da Rocha; Omena, Cristhiane Maria Bazílio de; Menezes, Maria Emília da Silva; Cabral Júnior, Cyro RêgoVerificar o consumo da bebida café segundo a quantidade ingerida e os métodos de preparo, e sua associação com o perfil lipídico sérico de hipertensos e diabéticos.Item Café e saúde humana: um enfoque nas substâncias presentes na bebida relacionadas às doenças cardiovasculares(Pontifícia Universidade Católica de Campinas, 2010) Lima, Fabiana Accioly de; Santána, Antônio Euzébio Goulart; Ataíde, Terezinha da Rocha; Omena, Cristhiane Maria Bazílio de; Menezes, Maria Emília da Silva; Vasconcelos, Sandra Mary LimaO café é a bebida mais consumida no Brasil e no mundo ocidental. O fato de ser uma bebida tão popular, aliado à sua importância econômica, explica o interesse por estudos sobre o café, desde a sua composição até seus efeitos na saúde humana. Dentre as diversas substâncias presentes na composição química do café, além dos nutrientes, destacam-se a cafeína, os diterpenos cafestol e kahweol e os ácidos clorogênicos, o que faz do café uma importante fonte dietética destes compostos. Muitos estudos têm verificado a influência de seus constituintes na saúde, principalmente a cafeína vs a elevação da pressão arterial; o cafestol e o kahweol vs a dislipidemia; e ácidos clorogênicos vs proteção cardiovascular, por suas propriedades antioxidantes. Este artigo tem como objetivo apresentar de forma sucinta a importância da bebida e sua composição química, os mecanismos fisiológicos envolvidos na elevação da pressão arterial e do colesterol sérico atribuíveis ao café, bem como estudos selecionados que verificaram a associação do consumo da bebida com estas doenças cardiovasculares.