Angiotensin converting enzyme inhibitory hydrolysate and peptide fractions from chicken skin collagen, as modulators of lipid accumulation in adipocytes 3 T3-L1, after in vitro gastrointestinal digestion.

Inhibitory activity against angiotensin-converting enzyme (IAACE) by chicken skin collagen hydrolysate (CSCH) and their peptide fractions before and after in-vitro gastrointestinal digestion, were evaluated; as well as their ability to modulate lipid accumulation in 3 T3-L1 adipocytes. Before digestion, peptide fraction <1 kDa (F4) showed the highest IAACE (p < 0.05) followed by CSCH. After these samples were digested, F4 presented an IAACE with IC50 similar to its digest (DF4) (188.84 and 220.03 µg/mL, respectively), which was 2-fold lower (p < 0.05) than IC50 of fraction <1 kDa from post-digested hydrolysate (FDH) (388.57 µg/mL). Nine peptides were identified as the potential ACE inhibitors in F4 and DF4. Addition of DF4 (800 µg/mL) reduced(p < 0.05) lipid accumulation by 83% within preadipocytes. A 45-60% reduction of lipid accumulation within differentiated adipocytes was obtained by adding FDH and DF4 (regardless the concentration). These results, digested CSCH and F4 with IAACE may be considered as potential adjuvants for obesity treatment.

Hydrolysates and peptide fractions from pork and chicken skin collagen as pancreatic lipase inhibitors.

The objective of this work was to obtain hydrolysates and peptide fractions from pork (PSC) and chicken (CSC) skin collagen extracts and to evaluate their ability as pancreatic lipase inhibitors. Collagen extracts were hydrolyzed with collagenase or a protease from Bacillus licheniformis (MPRO NX®) at 6, 12, and 24 h. After 24 h incubation, the highest degree of hydrolysis of PSC (p < 0.05) was obtained with collagenase (72.58%), while in CSC was obtained with MPRO NX® (64.45%). Hydrolysates obtained at 24 h had the highest inhibitory activity of lipase (p < 0.05). CSC/collagenase hydrolysates (10 mg/mL) presented the highest inhibitory activity (75.53%) (p < 0.05). Ultrafiltrated fractions >5 kDa from CSC/collagenase and PSC/MPRO NX® hydrolysates were the most bioactive fractions (IC50: 4.33 mg/mL). The highest were obtained by CSC peptides (IC50s: 6.30 and 6.08 mg/mL). These results may be considered as a novel approach to use collagen hydrolysates, or their peptide fractions, as promising natural inhibitors of pancreatic lipase.