ENCAPSULATION OF PROTEINS AND PEPTIDES WITH ANTI-OBESITY PROPERTIES: Study of the effect of trypsin inhibitor isolated from tamarind seeds on weight change and satiety.
Encapsulation; Nanotechnology; Nanoparticles with proteins; trypsin inhibitor; Stability; Storage.
Obesity is a severe disease and therefore drives research in the search for new strategies to combat it. In this sense, several peptides and proteins with satietogenic activity have been studied because they play an important role in regulating dietary intake and body weight. Thus, this thesis is divided into two chapters. The first was in a narrative review format, in which we sought to understand the influence of encapsulated bioactive proteins and peptides on weight reduction and satiety, how they can impact the nutritional status of obesity, and how encapsulation can enhance the bioactive effects of such molecules. For this, a integrative review was carried out through a search in databases, selecting studies that involved encapsulation of peptides and proteins and action in the modulation of weight or satiety. With this, studies demonstrated that encapsulating peptides and proteins can contribute to a series of functions, such as greater efficiency in reducing weight gain, changes in adipose tissue function, and the reduction of hormone levels that modulate appetite and body weight. In the second chapter, the effect of trypsin inhibitor isolated from tamarind seeds (TTI) nanoencapsulated in chitosan and isolated whey protein (ECW) was investigated, which, based on previous studies by the research group, is safe and presents potentiated bioactive properties concerning TTI. The objective was to evaluate the ECW regarding the protection of the encapsulated TTI when subjected to different environmental conditions (pH and temperature), and the bioactive potential in an in vivo experimental model compared to the TTI. The ECW was analyzed exposed to different conditions of pH (7.0, 3.0, and 7.0) and temperature (37°C, 7°C, and -18°C) regarding the interaction between the TTI and its encapsulating agents, being monitored by the antitrypsin activity. Subsequently, Wistar rats (n = 25) with obesity induced by a high glycemic index and high glycemic load (HGLI) diet for 17 weeks were divided into five groups, namely: no treatment (HGLI + water), treatment 1 ( nutritionally adequate diet), treatment 2 (with nutritionally adequate diet and ECW/12.5 mg/kg), treatment 3 (diet HGLI and EQPI/12.5 mg/kg) and treatment 4 (diet HGLI and TTI/25 mg/kg) kg). The groups were evaluated for ten days regarding the action on satiety, zoometric, biochemical and inflammatory parameters, highlighting that the dose of ECW administered contained ten times less TTI (2.5 mg/kg) compared to the dose of non-encapsulated TTI (25 mg/kg). ECW was able to efficiently engage TTI (0.0% trypsin inhibition, control, not subjected to TTI extraction). Exposing ECW to different pHs, only at gastric pH, significant antitrypsin activity was observed. And regarding exposure to temperatures, ECW showed high antitrypsin activity, similar to TTI, demonstrating the complete release of TTI contained in ECW. Obese Wistar rats treated with ECW significantly reduced body weight variation (p < 0.05). It was observed that only TTI treatment led to significant changes in inflammatory parameters (p < 0.05). The study showed that using lower concentrations of TTI in ECW, it was possible to perceive promising effects with perspectives of use in an oral delivery system with a gastric or intestinal release, aiming at the application in functional foods or beverages with purposes related to the management of obesity and its complications.