Análise do estresse oxidativo e da apoptose no ovário de ratas tratadas com isoflavonas da soja
Nenhuma Miniatura disponível
Data
2018-05-24
Autores
Teixeira, Cristiane de Paula [UNIFESP]
Orientadores
Simões, Manuel de Jesus [UNIFESP]
Tipo
Tese de doutorado
Título da Revista
ISSN da Revista
Título de Volume
Resumo
O envelhecimento ovariano caracteriza se pela diminuição da reserva folicular e diminuição da qualidade dos oócitos que culminou na menopausa, responsável por uma série de distúrbios e doenças crônicas que afetam seriamente a qualidade de vida das mulheres. O estresse oxidativo parece modular o declínio da fertilidade relacionado com a idade, induzindo a senescência celular e a apoptose. Os antioxidantes são investigados por atrasar o envelhecimento, e as isoflavonas de soja podem atuar como antioxidantes e inibir a apoptose. Objetivos: Analisar a apoptose e a modulação do estresse oxidativo no ovário de ratas de 3 e 12 meses de idade tratadas com isoflavonas da soja. Métodos: Vinte e seis ratas Wistar de 3 e 12 meses foram divididas em quatro grupos e diariamente tratadas com extrato de isoflavonas da soja (150 mg/kg/dia) ou apenas com solução veículo propilenoglicol por gavagem. Após oito semanas, os animais foram eutanasiados e os ovários retirados. O ovário direito foi processado para estudo morfológico (% de folículos ovarianos em seus diferentes estágios) e avaliado a apoptose (caspase 3 e BCL2). No ovário esquerdo foram analisados os níveis de espécies reativas de oxigênio, a capacidade antioxidante total e os níveis de peroxidação dos lipídeos, como biomarcador do estresse oxidativo. Resultados: Na análise histomorfométrica, notou se uma diminuição significativa apenas na percentagem de folículos atrésicos nas ratas de 12 meses que receberam isoflavonas. Observou se ainda uma diminuição significativa no número de células caspase 3 positivas nos animais de 3 e 12 meses submetidos às isoflavonas, já a imunopositividade para BCL2 apresentou se significativamente aumentada somente nas ratas de 12 meses. O tratamento com isoflavonas ainda promoveu aumento significativo da capacidade antioxidante total, além da diminuição significativa dos níveis de espécies reativas de oxigênio e da peroxidação dos lipídeos nas ratas de 3 e 12 meses. Conclusão: As isoflavonas da soja parecem reduzir a atresia folicular, a apoptose e o estresse oxidativo, bem como aumentam a capacidade antioxidante total no ovário de ratas. E, em parte, os efeitos anti apoptóticos das isoflavonas parecem estar relacionados com sua capacidade antioxidante.
Ovarian aging is characterized by declines in follicular reserve and diminished oocyte quality that culminates in menopause, responsible for several disorders and chronic diseases. Oxidative stress seems to modulate age-related decline in fertility, inducing cellular senescence and apoptosis. Antioxidants have been investigated to delay aging and soybean isoflavones could act as antioxidants and inhibit apoptosis. Objective: To investigate and oxidative stress modulation in the ovary of 3- and 12-month-old rats treated with soy isoflavones. Methods: Twenty-six female rats at 3- and 12-month-old were divided into groups and daily treated by gavage with soy isoflavone extract or propylene glycol vehicle. After 8 weeks, rats were euthanized and ovaries removed. Ovaries were processed for histomorphometric analysis (% follicles) and apoptosis (cleaved-caspase-3 and BCL2). Ovaries were subjected to reactive oxygen species levels, total antioxidant capacity and lipid peroxidation assays. Results: A significant decrease in atretic follicles was noticed in 12-month-old isoflavones-treated rats compared to age-matched controls. In isoflavone-treated groups, there was a decrease in cleaved-caspase-3 positive cells at 3- and 12-month-old rats, and an increase in BCL2-positive cells only in 12-month-old rats compared to age-matched controls. Isoflavones promoted an increase in total antioxidant capacity as well as a decrease in reactive oxygen species levels and in lipid peroxidation in both 3- and 12-month-old. Conclusion: Soy isoflavones can decrease follicular atresia, apoptosis and oxidative stress, as well as increase total antioxidant capacity in ovarian tissue of rats. The anti-apoptotic effects of soy isoflavones are, at least in part, related to the antioxidant capacity of these compounds.
Ovarian aging is characterized by declines in follicular reserve and diminished oocyte quality that culminates in menopause, responsible for several disorders and chronic diseases. Oxidative stress seems to modulate age-related decline in fertility, inducing cellular senescence and apoptosis. Antioxidants have been investigated to delay aging and soybean isoflavones could act as antioxidants and inhibit apoptosis. Objective: To investigate and oxidative stress modulation in the ovary of 3- and 12-month-old rats treated with soy isoflavones. Methods: Twenty-six female rats at 3- and 12-month-old were divided into groups and daily treated by gavage with soy isoflavone extract or propylene glycol vehicle. After 8 weeks, rats were euthanized and ovaries removed. Ovaries were processed for histomorphometric analysis (% follicles) and apoptosis (cleaved-caspase-3 and BCL2). Ovaries were subjected to reactive oxygen species levels, total antioxidant capacity and lipid peroxidation assays. Results: A significant decrease in atretic follicles was noticed in 12-month-old isoflavones-treated rats compared to age-matched controls. In isoflavone-treated groups, there was a decrease in cleaved-caspase-3 positive cells at 3- and 12-month-old rats, and an increase in BCL2-positive cells only in 12-month-old rats compared to age-matched controls. Isoflavones promoted an increase in total antioxidant capacity as well as a decrease in reactive oxygen species levels and in lipid peroxidation in both 3- and 12-month-old. Conclusion: Soy isoflavones can decrease follicular atresia, apoptosis and oxidative stress, as well as increase total antioxidant capacity in ovarian tissue of rats. The anti-apoptotic effects of soy isoflavones are, at least in part, related to the antioxidant capacity of these compounds.
Descrição
Citação
TEIXEIRA, Cristiane de Paula. Análise do estresse oxidativo e da apoptose no ovário de ratas tratadas com isoflavonas da soja. 2018. São Paulo, 100 f. Tese (Doutorado em Biologia estrutural e funcional) - Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, 2018.