Avaliação dos efeitos do extrato e da fração flavonoídica obtidos das folhas do maracujá (Passiflora edulis sims) sobre a modulação da nadph oxidase e agregação plaquetária em ratos diabéticos.

Abstract

Diabetes mellitus is among the chronic diseases considered emergency. Products obtained from medicinal plants has been presenting efficient therapeutic results on treatment for chronic diseases. With 56.3% of world production, Brazil is the world's largest producer and the largest consumer of passion fruit. Many studies have considered P. edulis as a promising species, including for the treatment of diabetes mellitus. Thus the aim of this study was to evaluate the possible effects of the dry extract of leaves of passion fruit on biochemical markers and platelet aggregation in diabetic rats. The dry extract was obtained by grinding in a hydroethanolic solution 70% (V/V). The flavonoid fraction was obtained by liquid-liquid partition. The isoorientin chemical marker was quantified by ultra-performace liquid chromatography coupled to mass spectrometry. The chemical characterization was performed by high performance liquid chromatography coupled to mass spectrometry. Male “Wistar” rats were treated with alloxan (150 mg/kg body weight dissolved in 0.9% saline) intraperitoneally, dry extract was administred (0.2 g extract / kg) and flavonoid fraction was administred (20 mg flavonoid / kg) to normal and diabetic rats, for ninety days. The control and diabetic groups received water only. Platelet aggregation was performed in aggregometer to 37°C. The production of oxidizing species in platelets from diabetic and non-diabetic rats in the presence and absence of phorbol myristate acetate was evaluated by chemiluminescence. Biochemical markers were determined in serum by enzymatic method and glycated hemoglobin was evaluated by high performance liquid chromatography on Bio-Rad brand equipment. Our results suggest the presence of several flavonoids derived from apigenin and luteolin, being most c-heterosides. Chemical marker quantification confirms the presence of isoorientin, being the butanolic fraction with the highest isoorientin content (6.1%). The induction of diabetes mellitus led to hyperglycemia as well as the increase in levels of fructosamine and glycated hemoglobin, presenting classic signs of diabetes polydipsia, polyphagia and weight loss. Diabetes mellitus induced increased production of oxidant species and platelet aggregation. The treatment of the animals with the crude extract and flavonoid fraction was able to reduce fluid intake, solids consumption, glycemic levels, serum levels of fructosamine, platelet aggregation and the production of oxidant species in diabetic animals. All these results suggest that P. edulis leaf dry extract can present a beneficial health on the diabetic state, preventing the appearance of its complications.