Avaliação farmacológica antidiabética do extrato aquoso de Justicia secunda Vahl em modelos in vitro e in vivo: insights nutracéuticos

Abstract

Diabetes Mellitus (DM) is a metabolic disorder characterized by chronic hyperglycemia due to defects in insulin secretion or action. Its management involves early diagnosis and strict glycemic control to prevent serious complications. Given the side effects of synthetic drugs, there is growing interest in natural therapeutic alternatives. Bioactive compounds of plant origin have stood out for their efficacy, lower toxicity, and reports of traditional use. In this context, species of the genus Justicia have been studied for their hypoglycemic potential, showing promise in the development of new antidiabetic drugs. Therefore, the aim of this study is to evaluate the activity of the aqueous extract from Justicia secunda leaves on glucose metabolism. The leaves of Justicia secunda were collected at Embrapa Eastern Amazon, and transportation was carried out under refrigeration. The aqueous extract of Justicia secunda (EAJS) was obtained by infusion of dried and ground leaves. The cytotoxicity of EAJS was evaluated in C2C12 cells by Hoechst 33342 and propidium iodide staining, while α-glucosidase enzyme inhibition was measured using a spectrophotometric assay with a positive control (acarbose). In in vivo tests, mice underwent glucose tolerance tests and insulin tolerance tests in insulin-resistant animals induced by dexamethasone, and lipid profile and pancreatic histological changes were also evaluated. In in vitro models, the extract showed significant inhibition of α-glucosidase, with efficacy comparable to acarbose, and without cytotoxicity at low concentrations in C2C12 cells. In in vivo studies, EAJS significantly reduced blood glucose levels in hyperglycemic mice, especially at doses of 100 and 250 mg/kg, with an effect comparable or superior to dapagliflozin. Furthermore, the extract restored insulin sensitivity in the dexamethasone-induced resistance model, promoting a marked increase in insulin response. Thus, these findings support the use of Justicia secunda and highlight its potential as a promising source for the development of a new antidiabetic drug or as a food coloring for adjuvant treatment of diabetes mellitus.