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

Abstract

Lactobacillus delbrueckii ssp. lactis CRL 581, a thermophilic lactic acid bacterium used as a starter culture for the manufacture of several fermented dairy products, possesses an efficient proteolytic system that 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 ssp. lactis CRL 581 from milk proteins, the aim of this work was to analyze the anti-mutagenic 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 Crohns disease murine model. The hydrolysate was administered to mice 10 d before the intrarectal inoculation of TNBS. The mice that received beta-casein hydrolysate previously to TNBS showed decreased mortality rates, faster recovery of initial body weight loss, less microbial translocation to the liver, decreased beta-glucuronidase and myeloperoxidase activities in the gut, and decreased colonic macroscopic and microscopic damage compared with the animals that did not receive this hydrolysate. In addition, beta-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 ssp. lactis CRL 581 and open up new opportunities for developing novel functional foods.