Produtos naturais na prevenção de alterações bioquímicas, oxidativas e/ou histopatológicas associadas a doenças metabólicas: estudo em modelo animal de Hipotireoidismo e Diabetes Mellitus Tipo 2

Abstract

Hypothyroidism and Type 2 Diabetes Mellitus (DM2) are two important diseases that significantly affect the quality of life of patients and increase the risk of developing other pathologies. Among the mechanisms involved in the pathophysiology and aggravation of hypothyroidism and T2DM are mainly oxidative stress and cholinergic deficit. Given the complexity of hypothyroidism and DM2, the strong relationship between these and cognitive disorders, as well as the ineffectiveness of existing treatments in preventing or reversing the changes found in patients with these disorders, it is necessary to search for new therapeutic alternatives. Therefore, this study aimed to evaluate the possible preventive effects of resveratrol and Psidium cattleianum (P. cattleianum) against metabolic, biochemical, oxidative, cholinergic and histological changes resulting from hypothyroidism and DM2. For this, adult male Wistar rats were used in experimental models of hypothyroidism, induced by methimazole, and of DM2, induced by a high-fat diet and a single dose of streptozotocin. In both models studied, during the experimental period of 30 days, the animals received daily, once a day, resveratrol or hydroalcoholic extract of P. cattleianum by the intragastric route. The results referring to the hypothyroidism model showed that resveratrol, despite not promoting an increase in the levels of thyroid hormones, significantly prevented the increase in the activity of the enzyme acetylcholinesterase, preventing the cholinergic deficit. Furthermore, it prevented the increase in the levels of reactive oxygen species (ROS) in serum and brain, and the increase in the levels of thiobarbituric acid reactive substances (TBARS), and the decrease in catalase enzyme (CAT) activity and total thiol in the brain of hypothyroid animals. Thus, resveratrol proved to be a potential neuroprotective and antioxidant agent. In a T2DM model, the P. cattleianum extract prevented serum biochemical alterations, such as an increase in glucose, total cholesterol, triacylglycerols and VLDL, in addition to preventing an increase in ROS and TBARS levels and a decrease in CAT and superoxide dismutase enzyme activity. In addition, it protected the liver and pancreas from cellular and structural changes and necrosis resulting from induced T2DM. Thus, the P. cattleianum extract proved to be a promising antioxidant, antihyperglycemic and antilipemic. In view of the results presented, it was possible to understand the role of natural products studied here in animal models of hypothyroidism and T2DM and to consider them effective in preventing these metabolic diseases and their aggravations.