Efeito do inibidor de tripsina isolado de sementes de tamarindo nanoencapsulado sobre parâmetros bioquímicos em ratos Wistar superalimentados com dieta de alto índice glicêmico

Abstract

Studies have shown the benefits of Trypsin Inhibitor isolated from Tamarind seeds (Tamarindus indica L.) (TTI), which improves several biochemical parameters in Wistar rats. However, alternatives are sought to intensify the effect of TTI, through encapsulation, which allows a controlled release and potentialize the bioactive effect. In this study, we investigated the impact of nanoencapsulated TTI on chitosan and whey protein isolate (ECW) on biochemical parameters (glycemia, insulin and lipid profile) of Wistar rats overfeed with high glycemic index diet (HGLI), in addition to evaluating the in vitro stability of the ECW against the physiological conditions of the gastrointestinal tract (GIT). The nanoparticles were synthesized by nanoprecipitation using an aqueous solution containing chitosan, whey protein isolate and TTI (2: 2: 1 w/w/w) (ECW) and without ITT (2: 2 w/w) (CW). The nanoencapsulates were mainly characterized by morphology (SEM) and particle size (Laser Diffraction). They were also evaluated for stability to in vitro gastrointestinal tract conditions being performed in the three phases, oral, gastric and intestinal, and monitored by antitrypsin activity and High-Efficiency Liquid Chromatography (HPLC). The nanoparticles were administered in vivo by gavage (12.5 mg/kg of ECW and 10.0 mg/kg of CW) in Wistar rats overfeed with HGLI diet and investigated for biochemical parameters and histopathological analysis of the pancreas. ECW and CW have spherical shapes, smooth surfaces and agglomeration and, respectively, mean diameter of 117.4 nm (24.1) and 123.9 (11.3), and polydispersity index of 0.370 (0.004) and 0.225 (0.013).The results obtained in conditions simulating digestibility showed that ECW maintained the antitrypsin activity in 95.5% in the gastric phase, whereas the TTI (control) was hydrolyzed, completely losing the activity and characteristic protein peak observed by HPLC. In the presence of intestinal enzymes, ECW and TTI were susceptible to assay conditions, as confirmed by HPLC. In Wistar rats overfeed with HGLI diet, ECW and CW significantly reduced glycemia and HOMA IR, and only ECW increased HDL-c (p <0.05). Regarding the histopathology of the pancreas, ECW obtained better results regarding tissue repair and aspects related to organ normality and functionality. It was possible to show that the nanoencapsulation promoted better protection of the TTI in the desired condition and improvement of the biochemical parameters related to the Metabolic Syndrome, using a low TTI dosage.