Prospecção químico-farmacológica do extrato hidroalcoólico das amêndoas de Syagrus cocoides Martius e desenvolvimento de produtos tecnológicos

Abstract

Systemic Arterial Hypertension (SAH) is one of the leading causes of global morbidity and mortality. Treatment is based on the use of medications and lifestyle changes. Among the groups of antihypertensive drugs used for this purpose, diuretics show good efficacy; however, they are associated with adverse effects and therapeutic failures, which justifies the search for new natural alternatives. The plant species Syagrus cocoides Martius, native to Brazil, has shown antihypertensive potential, but its diuretic activity had not yet been explored. The aim of this study was to carry out the bioprospecting of S. cocoides through the evaluation of the phytochemical and pharmacological profiles of the hydroalcoholic extract of its kernels (SYA), with emphasis on diuretic activity in rats. Fruits of S. cocoides were collected in São Luís (MA, Brazil), and the kernels were subjected to drying, grinding, maceration, and extraction with a 70% hydroalcoholic solution to obtain the extract. The chemical characterization of SYA included the determination of total phenols and flavonoids by spectrophotometry, evaluation of antioxidant potential by the DPPH assay, and identification of constituents by GC/MS. For the pharmacological assays, healthy male Wistar rats (Rattus norvegicus), weighing between 150 200 g, were used. The rats received distilled water (0.01 g/kg, orally) and were individually housed in metabolic cages. After 6 hours, urine was collected and volume measured. Animals that excreted at least 40% of the administered water volume were selected for the study. For the evaluation of the diuretic effect, animals were randomized into four experimental groups (n = 5). In the acute protocol, rats received distilled water (0.01 g/kg), hydrochlorothiazide (0.025 g/kg), or SYA at single doses of 0.1 g/kg and 0.3 g/kg, and were monitored for 24 hours. In the seven-day subchronic protocol, groups received distilled water (0.01 g/kg), furosemide (0.01 g/kg), or SYA (0.1 g/kg and 0.3 g/kg). In both protocols, urinary volume, urinary excretion, diuretic action, and diuretic activity were determined, as well as serum biochemical analyses (glucose, calcium, urea, creatinine, total proteins, albumin, globulin, Na⁺, K⁺, Cl⁻, and osmolarity) and urinary analyses (glucose, calcium, urea, creatinine, and osmolarity). In the acute protocol, latency to the first micturition was additionally evaluated. In the subchronic protocol, water and food intake and body weight evolution were also monitored, along with the determination of urinary flow, pH, density, natriuretic and saluretic activity, carbonic anhydrase inhibitory potential, and the relative weight of target organs (kidneys, heart, lungs, liver, and spleen). SYA showed a high concentration of phenols (266.38 ± 0.01 mg GAE/g), flavonoids (83.50 ± 1.98 mg QE/g), and strong antioxidant potential (91% DPPH inhibition). GC/MS analysis identified 19 compounds, with caprylic acid standing out (37.62%). In the acute test, SYA significantly reduced micturition latency and increased urinary volume and electrolyte excretion, especially Na⁺, K⁺, and Cl⁻, with effects sustained for 24 hours. In the subchronic study, a progressive increase in diuresis was observed from the second day onward, satisfactory natriuresis, and carbonic anhydrase inhibitory potential, along with a slight increase in serum glucose, reduction in K⁺ and blood urea nitrogen, increased urinary creatinine and urinary osmolarity, without evidence of significant toxicity in target organs. SYA demonstrated a rapid and sustained diuretic effect, associated with the presence of bioactive compounds with antioxidant action. The extract showed good tolerability and diuretic efficacy, highlighting its diuretic potential for the management of SAH. Studies involving chronic administration of SYA and investigation of its mechanisms of action will be necessary to further elucidate the diuretic effect observed in this study and to support future stages of clinical evaluation for its regulation and validation.