Lipid-lowering effect of microencapsulated peptides from brewer's spent grain in high-sucrose diet-fed rats

Brewer's spent grain (BSG) -a byproduct generated from the processing of beer-brewing industry-is currently recognized as an important source of bioactive peptides with potential health benefits. In previous studies we demonstrated that peptides obtained from BSG (BSG-P) can exert in vitro biofunctional activities including hypolipidemic effects. However, there are no studies about the effects of gastrointestinal digestion on BSG lipid-lowering peptides and it is unknown whether the bioactive properties observed in vitro remain in vivo. The aims of this work were to evaluate the microencapsulation as strategy to preserve hypolipidemic BSG-P under a simulated gastrointestinal digestion, and the bioavailability of microencapsulated BSG-P using a rodent model of hyperlipidemia and other metabolic-related disorders induced by the consumption of a high-sucrose diet. In vitro studies showed that microencapsulation improved the BSG-P reduced hypolipidemic activity observed under a simulated gastrointestinal digestion by increasing the inhibition of the fat digestion enzymes, pancreatic lipase and cholesterol esterase. Furthermore, in vivo studies demonstrated that microencapsulated BSG-P were also able to reduce the increased serum lipid levels (triglycerides-TG- cholesterol and free fatty acids), energy intake, visceral adipocytes size and TG content observed in sucrose-rich diet-fed rats. This was accompanied by reduced liver lipids levels and the activities of key enzymes involved in dietary fat absorption. Therefore, our findings show that microencapsulation is a useful strategy to preserve the hypolipidemic activity of BSG-P and support the concept that microencapsulated BSG-P would be an interesting and cheaper natural source to prevent hyperlipidemias and its related-disorders.