Immunomodulatory activity of protein hydrolysates derived from Virgibacillus halodenitrificans SK1-3-7 proteinase.

Modulation of inflammation-related immune response on THP-1 macrophages of protein hydrolysates derived from tilapia mince， casein and pea protein， were investigated. The protein substrates were hydrolyzed by Virgibacillus halodenitrificans SK1-3-7 proteinase. The degree of hydrolysis (DH) of casein was observed to be the highest throughout the course of hydrolysis. When challenging THP-1 macrophages， tilapia mince hydrolysate (TMH) enhanced innate immunity through induction of IL-1β and COX-2 expression. Anti-inflammatory activity was observed in casein hydrolysate (CH) and pea protein hydrolysate (PPH) by attenuating lipopolysaccharide- (LPS) induced pro-inflammatory gene expression in THP-1 macrophages. CH suppressed IL-1β， IL-6， IL-8， TNF-α and COX-2， while PPH reduced LPS-induced IL-6 and TNF-α responses. In addition， CH and PPH showed stronger suppression of LPS-induced pro-inflammatory gene expression compared with non-hydrolyzed casein and pea protein. These results suggest that TMH， CH and PPH prepared from V. halodenitrificans SK1-3-7 proteinase are potential functional food ingredients with immunomodulatory activity.