Effect of the intake of whey proteins, their peptides and amino acids on the heat shock proteins (HSPs) and health related parameters in rats

Author(s)

Carolina Soares de Moura

• Document type: Doctoral Thesis
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Engenharia de Alimentos
• Defense date: 2016-10-10

Examining board members

Jaime Amaya Farfán; Claudio Cesar Zoppi; Elisa de Almeida Jackix; Mário Roberto Maróstica Junior; Priscila Neder Morato

• Advisor: Jaime Amaya Farfán

Abstract

The whey proteins (WPC) are known to have functional food characteristics, which may be magnified during digestion. One of the advantages hydrolyzed WPC (WPH) is to induce the production of heat shock proteins (HSPs), known to be endogenous proteins, members of a cell-shielding system that promotes cell resistance to adverse conditions to the body. Evidence suggests that the induction of HSPs promotes cytoprotection of muscle fibers, cell survival, preservation of muscle function, muscle damage repair and prevention of thermal and oxidative injury. In a study of our own we proved that PSLH is able to increase the expression of HSP70, hypothesizing that bioactive peptides present in PSLH act as metabolic flags thus explaining many of the positive functions assigned to the hydrolyzate. In addition, it is known that glutamine supplementation stimulates the expression of the HSP system, including during exercise, but the possibility that other amino acids could exert similar effects to those of glutamine has not been explored. The aim of this study was, therefore, to investigate the effect that the protein, some strategic peptides and amino acids, present in the whey hydrolyzate could have on the HSPs (HSP25, HAP60, HSP70, HSP90) and related parameters in rats that were exercised to offset homeostasis. The study was divided in three experiments: in the first, the PSLH was the dietary protein source, the second was a supplementation study with five bioactive peptides (isoleucyl-leucine (Ile-Leu) Leucyl-isoleucine (Leu-Ile), valyl-leucine (Val-Leu) Leucyl-valine (Leu-Val)), and the third with free amino acids: L-Leucine, L-isoleucine, L-valine, L-arginine and L-glutamine. All animals were submitted to acute exercise on a treadmill with the intention of inducing stress and offset homeostasis, except the control group, which remained at rest. The results showed that consumption of WPH increased the expression of HSP90 in both sedentary and exercised animals. However, no changes were caused by exercise or diet in the HSP60 or HSP25. Leu-Val increased HSP90, HSP70 and HSP25 expression in muscle, while Ile-Leu increased muscle and serum HSP70 and HSP60 in muscle. Supplementation with arginine induced HSP70 and HSP90 at the same intensity as glutamine. All amino acids increased HSP60 associated with the exercise, except for valine, but none affected the expression of HSP25. Based on the above data we conclude that while WPH stimulates HSPs and stimulates various factors related to cell preservation in rat muscle, dipeptides Leu-Val and Ile-Leu stood out for stimulating the expression of HSPs and various other parameters, and that arginine may have a protective function, similar to that of glutamine. The data also suggest that the selected peptides and amino acids are responsible for several positive functions attributed to the consumption of hydrolyzed whey protein and especially as an alternative to raise HSPs and mitigate cellular injuries (AU)

• FAPESP's process: 13/02862-0 - Effect of whey proteins intake, peptides and amino acids in the heat shock proteins (HSPs) and related parameters in rats
• Grantee: Carolina Soares de Moura
• Support Opportunities: Scholarships in Brazil - Doctorate