Adriana Prais Botelho

Os efeitos do ácido linoléico conjugado no metabolismo animal: avanço das pesquisas e perspectivas para o futuro

This systematic review without date restrictions is about the physiological effects of conjugated linoleic acid on regression of carcinogenesis, oxidative stress, glucose and lipid metabolism and change in body composition. The objective was to establish the historical aspect of research advances regarding conjugated linoleic acid, considering original articles reporting work on animals, cell cultures and humans. Regarding the researches on the anticarcinogenic effect of conjugated linoleic acid, innumerous evidences were found in this respect, especially in the regression of mammary and colon tumors induced by both isomers which act distinctively. The researchers devoted considerable effort to reinvestigate the antioxidant properties of conjugated linoleic acid. Although the antioxidant properties have been investigated, pro-oxidant effect has been identified leading to oxidative stress in humans. Few studies demonstrated significant beneficial effects of conjugated linoleic acid on the metabolism of lipids and glucose and on the reduction of body fat, especially in humans. Studies with adverse effects were also identified. There is strong indication that the action of this conjugated fatty acid on a class of transition factors - the peroxisome proliferator-activated receptor - and on the consequent modulation of gene expression can be the fundamental explanation of its physiological effects. The most recent studies reinforce the nutrigenomic concept, that is, the modulation of gene expression induced by compounds present in the foods consumed by humans. This current scenario stimulates the scientific community to seek a consensus on the effects of conjugated linoleic acid in humans, since it is naturally found in some foods; when these foods are consumed regularly and in appropriate amounts, they could help prevent and control innumerous chronic diseases.

A suplementação com ácido linoléico conjugado reduziu a gordura corporal em ratos Wistar

O acido linoleico conjugado, um conjunto de isomeros geometricos e de posicao do acido linoleico, vem sendo muito estudado devido ao seu efeito sobre a composicao corporal, promovendo reducao da massa gorda. O objetivo deste trabalho foi avaliar o efeito da suplementacao com acido linoleico conjugado sobre a composicao corporal de ratos Wistar saudaveis em crescimento. Um total de 40 ratos, divididos em quatro grupos, foram suplementados diariamente durante tres semanas com AdvantEdge® acido linoleico conjugado (EASTM) nas concentracoes 1,0%, 2,0% e 4,0% sobre o consumo diario de dieta, constituindo, respectivamente, os grupos AE1, AE2 e AE4, e com acido linoleico na concentracao de 2% sobre o consumo diario de dieta, constituindo o grupo-controle. Os animais foram suplementados por meio de entubacao orogastrica. Para a avaliacao da composicao corporal centesimal foi removido o conteudo intestinal para obtencao da carcaca vazia. Em seguida, a carcaca foi congelada em nitrogenio liquido, fatiada, liofilizada, moida e armazenada a -25°C, ate o momento das determinacoes de umidade, cinzas, proteina bruta e gordura. O grupo AE1 apresentou maior consumo de dieta e ganho de peso, mas nao diferiu quanto a eficiencia alimentar dos demais grupos (p< 0,05). Em relacao a composicao corporal, constatou-se reducao dos teores de gordura corporal dos grupos AE2 (11,2%) e AE4 (11,6%), quando comparados ao teor do grupo-controle (13,9%). A suplementacao com acido linoleico conjugado nas concentracoes de 2,0% e 4,0% sobre o consumo diario de dieta promoveu reducao de gordura corporal de 18,0% nos ratos Wistar.

Effect of conjugated linoleic acid supplementation on lipoprotein lipase activity in 3T3-L1 adipocyte culture

A suplementacao com acido linoleico conjugado pode reduzir a gordura corporal e aumentar a massa magra em diferentes especies. Alguns estudos tem demonstrado que o acido linoleico conjugado reduz a gordura corporal, por meio da inibicao da atividade de lipase lipoproteica em adipocitos. O objetivo deste estudo foi avaliar o efeito da suplementacao com uma mistura de isomeros do acido linoleico conjugado sobre a atividade da lipase lipoproteica em cultura de adipocitos 3T3-L1. Os adipocitos 3T3-L1 receberam acido linoleico (grupo controle) ou acido linoleico conjugado (grupo AE, suplementado com AdvantEdge® CLA, e grupo CO, suplementado com CLA One®) na concentracao de 1 mmol/L. A atividade de lipase lipoproteica livre de heparina foi analisada pela media da cultura de adipocitos. Apos 7 dias, a atividade da lipase lipoproteica livre de heparina mostrou menores valores nos grupos AE e CO, suplementados com acido linoleico conjugado. Estes resultados sugerem que um dos mecanismos pelo qual o acido linoleico conjugado seja capaz de reduzir a gordura corporal e a partir da reducao da atividade da lipase lipoproteica.

Conjugated linoleic acid supplementation: lipid content and hepatic histology in healthy Wistar rats

This work aimed to evaluate the effects of the consumption of two commercial conjugated linoleic acid (CLA) mixtures on lipid content and liver histology of healthy rats. The investigation was carried out using thirty rats divided into three groups: C (control), AE (AdvantEdge®CLA), and CO (CLA One®). The concentration of CLA was 2% of feed consumption, and the animals were supplemented daily for 42 days. The total lipid content of the liver was determined, and the histology of the organ was examined by Transmission Electronic Microscopy. The results of total liver lipid contents did not exhibit significant differences between the groups. With regard to hepatic histology, it was observed that although fat globules were visibly present in higher numbers and bigger size in the CLA groups, the organ histology was considered normal since both cytoplasm and organelles showed integrity. It was concluded that even though liver microscopic images indicated the presence of fat globules in the liver, from a statistical point of view, the supplementation for 42 days did not bring about lipid accumulation, nor did it alter hepatic histology.O objetivo do trabalho foi avaliar o efeito da suplementacao com duas misturas comerciais de acido linoleico conjugado (CLA) sobre o conteudo de lipides e a histologia hepatica de ratos saudaveis. Trinta ratos foram divididos em tres grupos: C (controle), AE (AdvantEdge®CLA) e CO (CLA One®). A concentracao de CLA foi de 2% em relacao ao consumo diario de dieta, e os animais foram suplementados diariamente durante 42 dias. O conteudo de lipides totais foi determinado e a histologia hepatica foi examinada por meio de Microscopia Eletronica de Transmissao. Nao houve diferenca significativa nos resultados de conteudo de lipides hepaticos entre os grupos. Quanto a histologia hepatica, embora tenha sido observada a presenca de globulos de gordura em maior numero e tamanho nos grupos suplementados com CLA, a histologia do orgao apresentou-se normal, visto que citoplasma e organelas estavam integros. Concluiu-se que nao houve acumulo de lipides nem alteracao da histologia hepatica apos 42 dias de suplementacao com CLA.

O EFEITO DA SUPLEMENTAÇÃO COM ÁCIDO LINOLÉICO CONJUGADO SOBRE O PERFIL LIPÍDICO SÉRICO EM RATOS

O acido linoleico conjugado (CLA), um conjunto de isomeros geometricos e de posicao do acido linoleico, vem sendo muito estudado devido aos seus efeitos beneficos em relacao a saude. O objetivo deste trabalho foi avaliar o efeito da suplementacao com acido linoleico conjugado sobre o perfil lipidico de ratos Wistar saudaveis em crescimento. Um total de 40 ratos, divididos em 4 grupos de 10 foram suplementados diariamente durante 3 semanas com AdvantEdge® CLA (EASTM) nas concentracoes 1%, 2% e 4% sobre o consumo diario de dieta, constituindo respectivamente os grupos AE1, AE2 e AE4, e com acido linoleico na concentracao de 2% sobre o consumo diario de dieta, constituindo o grupo controle (C). Os animais foram suplementados por meio de entubacao orogastrica. Para a avaliacao do perfil lipidico, o sangue dos animais foi coletado sob anestesia apos jejum de 12 horas e a determinacao dos triacilglicerois e colesterol total sericos realizada com a utilizacao de kits enzimaticos. Nao houve diferenca estatistica entre os teores de triacilglicerois (p≤0,05). Quanto aos valores de colesterol total, o grupo AE1 apresentou um teor superior ao grupo controle, ocorrendo uma reducao dos valores a medida que aumentava a quantidade suplementada de CLA.

Avaliação do perfil sensorial de chá light sabor pêssego

In this work, three different brands of light peach iced tea (A, B and C), purchased in a local market and packed in PET bottles were sensory analyzed. At first, Quantitative Descriptive Analysis (QDA) was conducted in order to obtain the sensorial profile, with eleven tasters, previously selected and trained. The product acceptance was evaluated by 33 consumers, representing the target public. The QDA results were submitted to ANOVA, Tukeys test and Principal Component Analysis (PCA). The sample A was mainly characterized by banana aroma and flavor; the sample B by artificial peach aroma and refreshment; while the sample C by sweetness and natural peach aroma. The acceptance test, analyzed by ANOVA and Tukeys test, showed a greater acceptance for the sample C. The colour of the samples was evaluated by the Cielab L*a*b* method and the sample C stood out by the red colour.

Suplementação com ácido linoléico conjugado: estabilidade oxidativa dos suplementos e correlações com conteúdo dos lípides totais hepáticos e indicadores da oxidação dos lípides biológicos de ratos Wistar

OBJECTIVE:The claimed action of conjugated linoleic acid as an antioxidant is unexpected and unclear, in view of its chemical structure - a conjugated diene, i.e., a fatty acid in its initial stage of autoxidation. Indeed, it can be speculated that it could act as a pro-oxidant, increasing oxidative stress in biological systems, nevertheless it has carbon-carbon bonds in the trans configuration. The objective of the present work was to evaluate the oxidative stability of commercial mixtures, and to investigate a possible correlation between conjugated linoleic acid supplementation and total hepatic lipid content, as well as some lipid oxidation indicators in rats. METHODS:A biological assay was done with thirty rats divided into three groups (n=10) characterized as control and supplemented with the commercial mixtures AdvantEdge® and One®. The mixtures were administered in the concentration of 2% of the total diet consumption, and animals were supplemented for 42 days. The total liver lipid content was determined, and the morphology of the organ was examined by optical microscopy. Peroxide and malondialdehyde indexes were determined in vitro in order to evaluate the oxidative stability of the supplements. Peroxide, malondialdehyde and 8-iso-PGF2α isoprostane and catalase were determined as biological lipid oxidation indicators. RESULTS:Results indicated a low in vitro oxidation stability of commercial mixtures. Associations between conjugated linoleic acid consumption and malondialdehyde (r=-0.7914, p<0.0001), and catalase (r=-0.5991, p=0.008) were moderate, negative and significant, demonstrating that conjugated linoleic acid reduced in vivo lipid oxidation. Total hepatic lipid content did not increase (22.42%, (SD=1.40%), and the organ remained morphologically undamaged. CONCLUSION:However, even though this CLA supplementation protocol did reduce lipid oxidation, a tendency was observed to an increase of 8-iso-PGF2 alpha isoprostane and peroxides induced by conjugated linoleic acid. Further research may be needed to verify its antioxidant effect.