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Abstract(s)
A Diabetes Mellitus (DM) é um problema de saúde pública e a sua incidência está a
aumentar drasticamente. O cérebro, especialmente o córtex cerebral, é muito suscetível a
flutuações dos níveis de glucose e ao stress oxidativo induzido pela hiperglicémia. O chá
(Camellia sinensis (L.)) é amplamente consumido, porém as propriedades antidiabéticas e
neuroprotetoras do chá branco permanecem por explorar. Neste trabalho investigámos os
efeitos do consumo diário de chá branco no córtex cerebral de ratos pré-diabéticos. Os
animais foram divididos aleatoriamente em três grupos: grupo controlo, grupo de ratos prédiabéticos
que ingeriram água e grupo de ratos pré-diabéticos que ingeriram chá branco. O
perfil metabólico do córtex foi avaliado e a expressão dos níveis dos transportadores de
glucose (GLUTs), da fosfofrutoquinase-1, da lactato desidrogenase (LDH) e do transportador
de monocarboxilato 4 foram também determinados. O perfil oxidativo do córtex foi obtido
através da avaliação do seu poder antioxidante (ensaio FRAP) e dos níveis de peroxidação
lipídica (ensaio TBARS) e de oxidação proteica (ensaio dos grupos carbonilo). A catalase e a
glutationa, bem como o conteúdo em glutamato, N-acetilaspartato, aspartato, colina,
ácido gama-aminobutírico, taurina e valina foram também determinados. Embora o
consumo diário de chá branco não tenha diminuído os níveis de glicémia no sangue,
melhorou a tolerância à glucose e a sensibilidade à insulina dos ratos pré-diabéticos. Além
disso, o consumo diário do chá branco alterou o perfil glicolítico do córtex cerebral dos
ratos pré-diabéticos, modulando a expressão dos GLUTs e o conteúdo em lactato e alanina.
O consumo de chá branco também foi capaz de restabelecer os níveis de oxidação proteica
e de peroxidação lipídica para valores controlo, no córtex de ratos pré-diabéticos. No geral,
o córtex cerebral de ratos pré-diabéticos que consumiram chá branco apresentou uma
maior capacidade antioxidante e uma expressão normalizada da catalase. Concluindo, o
consumo diário de chá branco por ratos pré-diabéticos melhora o perfil metabólico e
oxidativo do seu córtex cerebral, sugerindo que a ingestão de chá branco pode ser uma
estratégia boa, segura e económica para evitar os efeitos relacionados com a DM no córtex
cerebral.
Diabetes Mellitus (DM) is a major public health problem and its incidence is dramatically rising. The brain, particularly the cerebral cortex, is very susceptible to glucose fluctuations and hyperglycemia-induced oxidative stress. Even though tea (Camellia sinensis (L.)) is widely consumed, white tea antidiabetic properties remain largely unexplored. Herein, we investigated the effects of white tea daily consumption on the cerebral cortex of prediabetic rats. Animals were randomly divided in 3 groups: control and prediabetic rats drinking water or white tea. Cortex metabolic profile was evaluated and expression of glucose transporters (GLUTs), phosphofructokinase-1, lactate dehydrogenase (LDH), monocarboxylate transporter 4 levels was assessed. LDH activity was also determined. Cortex oxidative profile was determined by evaluating its antioxidant power, lipid peroxidation and protein oxidation levels. Catalase, glutathione, glutamate, Nacetylaspartate, aspartate, choline, gamma-aminobutyric acid, taurine and valine contents were determined. Daily white tea consumption ameliorated glucose tolerance and insulin sensitivity and altered the cortex glycolytic profile of prediabetic rats by modulating GLUTs expression and lactate and alanine contents. It also restored protein peroxidation levels, catalase expression and improved antioxidant capacity of the cortex of prediabetic rats. In conclusion, daily white tea consumption by prediabetic rats improves cerebral cortex metabolic and oxidative profile suggesting that it can be a good, safe and inexpensive strategy to prevent DM-related effects in the cerebral cortex.
Diabetes Mellitus (DM) is a major public health problem and its incidence is dramatically rising. The brain, particularly the cerebral cortex, is very susceptible to glucose fluctuations and hyperglycemia-induced oxidative stress. Even though tea (Camellia sinensis (L.)) is widely consumed, white tea antidiabetic properties remain largely unexplored. Herein, we investigated the effects of white tea daily consumption on the cerebral cortex of prediabetic rats. Animals were randomly divided in 3 groups: control and prediabetic rats drinking water or white tea. Cortex metabolic profile was evaluated and expression of glucose transporters (GLUTs), phosphofructokinase-1, lactate dehydrogenase (LDH), monocarboxylate transporter 4 levels was assessed. LDH activity was also determined. Cortex oxidative profile was determined by evaluating its antioxidant power, lipid peroxidation and protein oxidation levels. Catalase, glutathione, glutamate, Nacetylaspartate, aspartate, choline, gamma-aminobutyric acid, taurine and valine contents were determined. Daily white tea consumption ameliorated glucose tolerance and insulin sensitivity and altered the cortex glycolytic profile of prediabetic rats by modulating GLUTs expression and lactate and alanine contents. It also restored protein peroxidation levels, catalase expression and improved antioxidant capacity of the cortex of prediabetic rats. In conclusion, daily white tea consumption by prediabetic rats improves cerebral cortex metabolic and oxidative profile suggesting that it can be a good, safe and inexpensive strategy to prevent DM-related effects in the cerebral cortex.
Description
Keywords
Antioxidantes Camellia Sinensis Chá Branco Córtex Cerebral Metabolismo Pré-Diabetes