Avaliação farmacológica de frutos nativos em modelo animal de síndrome metabólica

Abstract

Metabolic syndrome is characterized by a variety of cardiovascular risk factors, such as hyperglycemia, insulin resistance, visceral obesity and dyslipidemia. Considering the complexity of this syndrome, the molecular heterogeneity presents in natural extracts credit them as important agents in the therapy of this disorder. Thus, the aim of the present study was to characterize phytochemically the hydroalcoholic extracts of red fruits (Psidium cattleianum and Eugenia uniflora) and to evaluate their effects on metabolic, behavioral, neurochemical, inflammatory and thromboregulatory parameters in the brain and/or blood of 21- day-old male Wistar rats submitted to the model of metabolic syndrome induced by consumption of highly palatable diet (HPD). The animals were treated for 150 days and divided into 6 experimental groups: standard chow (SC) and water by gavage, SC and extract of P. cattleianum or E. uniflora, HDP and water by gavage, HPD and extract of P. cattleianum or E uniflora. The dose of the extracts administered was 200 mg/kg/day by gavage. The liquid chromatography coupled to high efficiency mass spectrometry (LC/MS) analysis showed the presence of nine anthocyanins in the E. uniflora extract and revealed the cyanidin-3-O- glycoside as the only anthocyanin present in the extract of P. cattleianum. Animals exposed to HPD showed glucose intolerance, visceral fat and weight gain, elevated serum glucose, triglycerides, total cholesterol, LDL cholesterol and interleukin-6, as well as increased immobility time in the forced swimming test. These changes were prevented by the extracts tested. Additionally, these extracts decreased lipid peroxidation and prevented the reduction of superoxide dismutase and catalase activities in the prefrontal cortex, hippocampus and striatum. Furthermore, both extracts prevented the increase of cortical acetylcholinesterase activity caused by HPD. The extract of P. cattleianum prevented the increase in nitrite levels, reactive oxygen species and restored Ca2+-ATPase activity in the brain structures tested, as well as Na+, K+-ATPase activity in the prefrontal cortex and hippocampus. Treatment with extracts of P. cattleianum and E. uniflora prevented the reduction in NTPDase activity in lymphocytes and platelets and the 5'-nucleotidase in platelets caused by DHP. Moreover, HPD increased the activity of adenosine deaminase in lymphocytes and serum. However, treatment with E. uniflora extract prevented this increase. In addition, both extracts prevented the increase of acetylcholinesterase activity in lymphocytes and butyrylcholinesterase in serum induced by HPD. In conclusion, the extracts of E. uniflora and P. cattleianum demonstrated antihyperglycemic, antihyperlipidemic, anti-inflammatory, antithrombotic effects, as well as neuroprotective properties, proving to be potential therapeutic agents in the prevention of complications associated to the metabolic syndrome.