Anti-inflammatory effects of a casein hydrolysate and its peptide-enriched fractions on TNFα-challenged Caco-2 cells and LPS-challenged porcine colonic explants

Bioactive milk peptides are reported to illicit a range of physiological benefits and have been proposed as potential functional food ingredients. The objective of this study was to characterize the anti-inflammatory properties of sodium caseinate (NaCAS), its enzyme hydrolysate (EH) and peptide-enriched fractions (5 kDa retentate [R], 1 kDaR and 1 kDa permeate [P]), both in vitro using a Caco-2 cell line, and also ex vivo using a porcine colonic tissue explant system. Caco-2 cells were stimulated with tumour necrosis factor alpha (TNFα) and co-treated with casein hydrolysates for 24 h. Following this, interleukin (IL)-8 concentrations in the supernatant were measured using enzyme-linked immunosorbent assay. Porcine colonic tissue was stimulated with lipopolysaccharide and co-treated with casein hydrolysates for 3 h. The expression of a panel of inflammatory cytokines was measured using qPCR. While dexamethasone reduced the IL-8 concentration by 41.6%, the 1 kDaR and 1 kDaP fractions reduced IL-8 by 68.7% and 66.1%, respectively, relative to TNFα-stimulated Caco-2 cells (P < 0.05). In the ex vivo system, only the 1 kDaR fraction elicited a decrease in IL1-α, IL1-β, IL-8, TGF-β and IL-10 expression (P < 0.05). This study provides evidence that the bioactive peptides present in the 1 kDaR fraction of the NaCAS hydrolysate possess anti-inflammatory properties in vitro and ex vivo. Further in vivo analysis of the anti-inflammatory properties of the 1 kDaR is proposed

Dairy matrix effects: response to consumption of dairy fat differs when eaten within the cheese matrix—a randomized controlled trial

peer-reviewedBackground Dairy fat consumed as cheese has different effects on blood lipids than that consumed as butter. It is unknown whether the effect is specific to fat interaction with other cheese nutrients (calcium, casein proteins), or to the cheese matrix itself. Objective We aimed to test the effect of 6 wk daily consumption of ∼40 g dairy fat, eaten within macronutrient-matched food matrices, on markers of metabolic health, in overweight adults aged ≥50 y. Design The study was a 6-wk randomized parallel intervention; 164 volunteers (75 men) received ∼40 g of dairy fat/d, in 1 of 4 treatments: (A) 120 g full-fat Irish cheddar cheese (FFCC) (n = 46); (B) 120 g reduced-fat Irish cheddar cheese + butter (21 g) (RFC + B) (n = 45); (C) butter (49 g), calcium caseinate powder (30 g), and Ca supplement (CaCO3) (500 mg) (BCC) (n = 42); or (D) 120 g FFCC, for 6 wk (as per A) (n = 31). Group D first completed a 6-wk “run-in” period, where they excluded all dietary cheese before commencing the intervention. Results There was no difference in anthropometry, fasting glucose, or insulin between the groups at pre- or postintervention. However, a stepwise-matrix effect was observed between the groups for total cholesterol (TC) (P = 0.033) and LDL cholesterol (P = 0.026), with significantly lower postintervention TC (mean ± SD) (5.23 ± 0.88 mmol/L) and LDL cholesterol (2.97 ± 0.67 mmol/L) when all of the fat was contained within the cheese matrix (Group A), compared with Group C when it was not (TC: 5.57 ± 0.86 mmol/L; LDL cholesterol: 3.43 ± 0.78 mmol/L). Conclusion Dairy fat, eaten in the form of cheese, appears to differently affect blood lipids compared with the same constituents eaten in different matrices, with significantly lower total cholesterol observed when all nutrients are consumed within a cheese matrix This trial was registered at ISRCTN as ISRCTN86731958.Enterprise Irelan