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Systematic evaluation of oxidative and inflammatory parameters in obese rats chronically supplemented with green tea extract (Camellia sinensis)

Grant number: 11/19216-8
Support type:Regular Research Grants
Duration: February 01, 2012 - January 31, 2014
Field of knowledge:Biological Sciences - Physiology
Principal Investigator:Rosemari Otton
Grantee:Rosemari Otton
Home Institution: Pró-Reitoria de Pós-Graduação e Pesquisa. Universidade Cruzeiro do Sul (UNICSUL). São Paulo , SP, Brazil

Abstract

Obesity is currently one of the most serious public health problems around the world. The prevalence of this disease has grown tremendously in recent decades, both in developed and developing countries. Among the medical complications associated with obesity we can mention cardiovascular disease, hypertension, dyslipidemia, diabetes mellitus and different types of cancer. We can define obesity as chronic energy storage, with an etiology based on the higher energy consumption than necessary for the maintenance of daily activities. One of the most important discoveries made recently in the investigation of obesity was the role of chronic inflammation that occurs in obese patients. Indeed, adipocytes release a series of proteins associated with inflammation in obesity, especially TNF-alpha, IL-6 and other acute phase proteins. Moreover, the levels of reactive oxygen species (ROS) are increased in obesity, an essential component of metabolic syndrome. As a defense mechanism, the body produces a series of endogenous antioxidants which can scavenger harmful ROS in order to maintain an optimal balance between oxidant and antioxidant, thus maintaining normal cell function. Tea made from the processed leaves of Camellia sinensis is consumed in different parts of the world as green tea, black tea or oolong tea. Clinical studies in Asian populations have shown that daily consumption of green tea may be associated with reduced risk for cardiovascular disease. Catechins, the main polyphenolic compounds in green tea, exert vascular effects through multiple mechanisms, including antioxidant, anti-hypertensive, anti-inflammatory, anti-proliferative, anti-thrombogenic, antimutagenic, antidiabetic and lipid lowering effects. This study aims to evaluate systematically the effects of chronic supplementation of green tea extract on inflammatory and oxidative stress indicators and those related to obesity in mice induced to obesity by cafeteria diet. The functions of lymphocytes and neutrophils, the oxidative and inflammatory profile in plasma and tissues (liver, epididymal adipose tissue, spleen, brain, kidneys and gastrocnemius muscle) will be assessed. In addition to the in vivo experimental design we will also prepare an in vitro mixture containing the four major catechins found in green tea. The function of lymphocytes and neutrophils from human peripheral blood of healthy individuals will be assessed. These in vitro experiments will be performed in order to evaluate the isolated effects of green tea catechins in parallel with the administration of total extract of green tea that contains other components besides the catechins. This study may contribute to the understanding of the involvement of oxidative stress in obesity and the specific action of green tea on immune cells (neutrophils and lymphocytes). Moreover, in the future, this functional food may also be indicated as an adjunct in the treatment of complications of obesity or at least to improve immune function. (AU)

Scientific publications (5)
(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)
MACEDO, RITA CASSIA; BONDAN, EDUARDO FERNANDES; OTTON, ROSEMARI. Redox status on different regions of the central nervous system of obese and lean rats treated with green tea extract. NUTRITIONAL NEUROSCIENCE, v. 22, n. 2, p. 119-131, FEB 1 2019. Web of Science Citations: 1.
ROCHA, ANDREA; BOLIN, ANAYSA PAOLA; LIMA CARDOSO, CLAUDIA ANDREA; OTTON, ROSEMARI. Green tea extract activates AMPK and ameliorates white adipose tissue metabolic dysfunction induced by obesity. EUROPEAN JOURNAL OF NUTRITION, v. 55, n. 7, p. 2231-2244, OCT 2016. Web of Science Citations: 23.
ALBUQUERQUE, K. F. F. S.; MARINOVIC, M. P.; MORANDI, A. C.; BOLIN, A. P.; OTTON, R. Green tea polyphenol extract in vivo attenuates inflammatory features of neutrophils from obese rats. EUROPEAN JOURNAL OF NUTRITION, v. 55, n. 3, p. 1261-1274, APR 2016. Web of Science Citations: 12.
MARINOVIC, M. P.; MORANDI, A. C.; OTTON, R. Green tea catechins alone or in combination alter functional parameters of human neutrophils via suppressing the activation of TLR-4/NF kappa B p65 signal pathway. TOXICOLOGY IN VITRO, v. 29, n. 7, p. 1766-1778, OCT 2015. Web of Science Citations: 24.
MOLINA, N.; BOLIN, A. P.; OTTON, R. Green tea polyphenols change the profile of inflammatory cytokine release from lymphocytes of obese and lean rats and protect against oxidative damage. International Immunopharmacology, v. 28, n. 2, SI, p. 985-996, OCT 2015. Web of Science Citations: 8.

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