ABSTRACT
Abstract The present study sought to evaluate the protective effect of Epigallocatechin-3-gallate (EGCG) and commercial green tea (GT) on eroded dentin using in vitro and in situ experimental models. For the in vitro experiment, matrix metalloproteinases (MMPs) were extracted from demineralized human coronary dentin powder (citric acid, pH 2.3) and assessed via a colorimetric assay and electrophoresis in gelatin. The gels were exposed to buffers with: control (no treatment), 0.05% sodium fluoride (NaF), 0.12% chlorhexidine digluconate (CHX), GT infusion, and 0.1% EGCG, and their respective activity was analyzed by zymography. For the in situ experiment, 20 healthy volunteers (aged 20-32 years) participated in this single-center, blind, crossover study. The subjects wore upper removable devices containing four human dentin blocks. Erosive challenge (coke-1 min) was performed four times/day/5 days. Blocks were treated for 1 min with: control (No treatment), 0.05% NaF, 0.1% EGCG, and GT. Thereafter, the specimens were subjected to stylus profilometry and SEM. ANOVA was used to evaluate dentin roughness and wear, with a significance level of 5%. In the zymography analysis, 0.12% CHX, GT, and 0.1% EGCG were found to inhibit the action of MMPs; however, in the colorimetric assay, only green tea inhibited the activity of MMPs. There were no significant differences observed in dentin roughness or wear (p > 0.05). Herein, EGCG and GT inhibited the activity of endogenous proteases, resulting in protection against erosion-induced dentin damage; however, they could not prevent tooth tissue loss in situ.
ABSTRACT
O trabalho objetivou avaliar o efeito da substituição da proteína da clara de ovo por proteína de soja crua na dieta de ratos em crescimento sobre o ganho de peso, consumo de ração, eficiência alimentar e parâmetros séricos (proteínas totais, albumina, aminotransferases, uréia, creatinina e amilase pancreática), visando estabelecer limites biologicamente seguros para inclusão de soja crua na dieta dos animais por períodos de curta duração. Foram utilizados 24 ratos divididos aleatoriamente em seis grupos de quatro animais e alimentados com dietas contendo cinco percentuais de substituição de proteína da clara de ovo por proteína de soja (0, 25, 50, 75 e 100%) e um grupo com dieta aprotéica. Os animais foram mantidos por 10 dias com fornecimento de água e alimento ad libitum. Os resultados obtidos revelaram que não houve diferença significativa no consumo entre os tratamentos testados. O ganho de peso e a eficiência alimentar observados no tratamento com 25% de substituição foram equivalentes aos obtidos com clara do ovo como única fonte de proteína. Albumina sérica, aminotransferases e creatinina não foram afetadas pelo aumento do percentual de soja crua, mas houve aumento da concentração de uréia no soro a partir de 50% de substituição. Proteínas totais e amilase pancreática sérica foram afetadas pela proteína da soja crua somente acima de 75% de substituição. Análises de regressão demonstraram que a substituição da proteína da clara de ovo por proteína de soja crua em até 30% foi inócua para o desempenho e parâmetros séricos de ratos em crescimento.
This work aimed to evaluate the replacement of egg white protein for raw soybean protein in diets for weaned rats on feed intake, body weight gain, feed efficiency and serum parameters (total protein,albumin, aminotransferases, urea, creatinine and pancreatic amylase). Twenty four weaned rats were randomly assigned to six groups of four animals which were fed diets containing five percentages of soybean protein (0, 25, 50, 75 and 100%), plus a non-proteic diet group. Animals were kept for 10 days with food and water ad libitum. Results showed that feed intake did not differ significantly among treatments tested. Body weight gain and feed efficiency of rats treated with 25% substitution diets did not differ from the control group. Serum albumin, aminotransferases and creatinine were not affected by increased amounts of soybean in rations, whilst serum urea was affected by inclusion of soybean in diets in values equal or above 50%. Total protein and pancreatic amylase were affected when soybean was present at 75% or more. Regression analysis showed that egg white protein replacement by soybean protein at up to 30% did not affect the tested traits of the growing rats.