Acute Administration of Tibolone Prevents Oxidative Stress in Ovariectomized Rats Fed High-Fat-and-Fructose Diet

Abstract

In addition to oxidative stress due to the increase of free radicals, estrogen deficiency is associated with changes in enzymatic activity, glutathione redox ratio (GSH/GSSG), and the content of oxidative markers such as malondialdehyde. Tibolone, a synthetic steroid, has been used as an elective treatment for the relief of menopausal symptoms. However, the acute effects of hormonal therapy with tibolone on metabolic parameters and oxidative stress markers associated with the first stages of estrogen deficiency are still unknown. The study aimed to evaluate if the acute administration of tibolone reduces oxidative stress in ovariectomized rats fed high-fat-and-fructose diet. Rats were fed a standard diet or a diet consisting of 10% lard-supplemented chow and 20% high-fructose syrup in the drinking water plus tibolone or vehicle for seven days. Weight, cholesterol, triglycerides, and glucose levels, as well as antioxidant enzymes and oxidative stress markers were quantified in the serum of each experimental group. It was observed that seven days of diet and tibolone treatment in the ovariectomized group reduced weight, triglycerides, cholesterol, glucose levels and advanced glycation end products but did not change GSH/GSSG ratio nor the enzymatic activity of superoxide dismutase. Also, both glutathione peroxidase and glutathione reductase activity decreased, as well as malondialdehyde levels. These results suggest that the acute treatment with tibolone prevented the changes in the metabolic parameters analyzed as well as the increase in the levels of malondialdehyde and AGEs induced by ovariectomy and high-fat diet.

Echography analysis of musculoskeletal, heart and liver alterations associated with endothelial dysfunction in obese rats

“…Thus, our results revealed that a high fat-fructose diet increased food intake, with marked weight gain due to the caloric contribution provided by fat and carbohydrates in obese group. We also found metabolic alterations, such as increases in glucose, triglycerides, cholesterol and the HOMA-IR index, similar to other studies that have used hypercaloric diets [13,15]. Hence, our results showed that with obesity triggered dysmetabolism, hyperglycemia and hypertriglyceridemia, as well as an increase of the levels of inflammatory cytokines (TNF-α, IL-6), are present.…”

“…One of the main organs affected by obesity is the liver, where long-term increases in lipogenesis and decreases in mitochondrial β-oxidation of nonesterified fatty acids, as well as hepatic triglyceride secretion, can contribute to fat accumulation in the liver, leading to the appearance of liver steatosis. Additionally, in a prospective longitudinal study, 86% of patients with NAFLD and progressive fibrosis were obese [14,15,21]. At the renal level, changes such as pelvic dilation were found in 50% of the obese group rats.…”

Echography analysis of musculoskeletal, heart and liver alterations associated with endothelial dysfunction in obese rats

“…Thus, our results revealed that a high fat-fructose diet increased food intake, with marked weight gain due to the caloric contribution provided by fat and carbohydrates in obese group. We also found metabolic alterations, such as increases in glucose, triglycerides, cholesterol and the HOMA-IR index, similar to other studies that have used hypercaloric diets [14,15]. Hence, our results showed that with obesity triggered dysmetabolism, hyperglycemia and hypertriglyceridemia, as well as an increase of the levels of in ammatory cytokines (TNF-a, IL-6), are present.…”

“…One of the main organs affected by obesity is the liver, where long-term increases in lipogenesis and decreases in mitochondrial β-oxidation of nonesteri ed fatty acids, as well as hepatic triglyceride secretion, can contribute to fat accumulation in the liver, leading to the appearance of liver steatosis. Additionally, in a prospective longitudinal study, 86% of patients with NAFLD and progressive brosis were obese [13,15,21].…”

Echographic analysis of the alterations musculoskeletal associated with endothelial dysfunction and obesity

“…In the present work, the results of this experimental model of obesity revealed alterations in metabolic parameters, such as lipids and HOMA-IR index, as mentioned by other studies where the use of hypercaloric diets similar to that used in this study, is associated with the early onset of lipidlike metabolic alterations [13], besides the endothelial damage that is had with the intake of hypercaloric diets, showing increase in TNF-α and adhesion molecules (ICAM-1 y VCAM-1). Together, with the ultrasound evaluation, the alterations of joint cysts and liver damage are highlighted.…”