B-casein hydrolysate generated by the cell envelope-associated proteinase of Lactobacillus delbrueckii subsp. lactis CRL 581 protects against trinitrobenzene sulfonic acid-induced colitis in mice

Abstract

Lactobacillus delbrueckii subsp. lactis CRL 581, a thermophilic lactic acid bacterium used as a starter culture for the manufacture of several fermented dairy products, possess an efficient proteolytic system which is able to release a series of potentially bioactive peptides (i.e. antihypertensive and phosphopeptides) from alpha- and beta-caseins. Considering the potential beneficial health effects of the peptides released by L. delbrueckii subsp. lactis CRL 581 from milk proteins, the aim of this work was to analyze the antimutagenic and anti-inflammatory properties of the casein hydrolysates generated by the cell envelope-associated proteinase of this bacterium. The ability of alpha- and beta-casein hydrolysates to suppress the mutagenesis of a direct-acting mutagen 4-nitroquinoline-N-oxide on Salmonella typhimurium TA 98 and TA 100 increased concomitantly with the time of casein hydrolysis. The anti-inflammatory effect of the beta-casein hydrolysate was evaluated using a trinitrobenzene sulfonic acid (TNBS) induced Crohn’s disease murine model. The hydrolysate was administered to mice 10 days before the intrarectal inoculation of TNBS. The mice that received B-casein hydrolysate previously to TNBS showed decreased mortality rates, faster recovery of initial body weight loss, lesser microbial translocation to the liver, decreased B-glucuronidase and myeloperoxidase activities in the gut and reduced colonic macroscopic and microscopic damages compared to the animals that did not receive this hydrolysate. In addition, B-casein hydrolysate exerted a beneficial effect on acute intestinal inflammation by increased interleukin 10 and decreased IFN-gamma production in the gut. Our findings demonstrated the health promoting attributes of the milk products fermented by L. delbrueckii subsp. lactis CRL 581 and open up new opportunities for developing novel functional foods.