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

Identification, characterization and hypolipidemic effect of novel peptides in protein hydrolysate from Protaetia brevitarsis larvae

The proteins were mainly derived from Protaetia brevitarsis larval extracts obtained using two empty intestine methods (traditional static method: TSM or salt immersion stress method: SISM) and extraction solvents (water: W or 50 % water-ethanol: W:E), and the proteins were used as objects to investigate the effect of emptying intestine methods on hypolipidemic peptides. The results revealed that the F-2 fractions of protein hydrolysate had stronger in vitro hypolipidemic activity, with the peptides obtained by SISM possessing a stronger cholesterol micelle solubility inhibition rate, especially in SISM-W:E-P. Moreover, a total of 106 peptides were tentatively identified, among which SISM identified more peptides with an amino acid number < 8. Meanwhile, five novel peptides (YPPFH, YPGFGK, KYPF, SPLPGPR and VPPP) exhibited good hypolipidemic activity in vitro and in vivo, among which YPPFH, VPPP and KYPF had strong inhibitory activities on pancreatic lipase (PL) and cholesteryl esterase (CE), and KYPF, SPLPGPR and VPPP could significantly reduce the TG content in Caenorhabditis elegans. Thus, P. brevitarsis can be developed as a naturally derived hypolipidemic component for the development and application in functional foods.

Research progress in lipid metabolic regulation of bioactive peptides

Hyperlipidemia poses a serious threat to human health and evaluating the ability of natural active substances to regulate disorders of lipid metabolism is the focus of food functionality research in recent years. Bioactive peptides are distinguished by their broad range of sources, high nutritional content, ease of absorption and use by the body, and ease of determining their sequences. Bioactive peptides have a wide range of potential applications in the area of medicines and food. The regulation of lipid metabolism disorder caused by bioactive peptides from different sources provides a reference for the development and research of bioactive peptides for lipid reduction.

Graphical Abstract

Anserine/Carnosine-Rich Extract from Thai Native Chicken Suppresses Melanogenesis via Activation of ERK Signaling Pathway

Skin hyperpigmentation is an aesthetic problem that leads to psychosocial issues. Thus, skin whitening agents from agro- and poultry-industrial co-products are considered high economic value ingredients of interest for sustainable application. Therefore, this study aimed to determine the cosmeceutical potential of anserine/carnosine-rich chicken extract (ACCE) from the Thai native chicken Pradu Hang Dam Mor Kor 55 (PD) meat. The chemical composition was identified and quantified using the HPLC-UV method. Then, the antioxidation potential of the extract was compared to that of L-anserine and L-carnosine, using 1,1-diphenyl-2-picrylhydrazyl assay and shikonin-induced production of reactive oxygen species in CCD-986Sk cell models, and the anti-melanogenesis effect in the MNT-1 melanoma cell line model was investigated. Furthermore, related mechanisms were identified using colorimetric tyrosinase assay and the Western blot technique. The ACCE was composed of L-anserine and L-carnosine as two major constituents. In a dose-dependent manner, ACCE, L-anserine, and L-carnosine manifested significant antioxidation potential and significant reduction of melanin production. Activation of the extracellular signal-regulated kinase (ERK) signaling pathway and inhibition of tyrosinase activity of ACCE were demonstrated as the mechanisms of the anti-melanogenesis effect. In conclusion, ACCE has been revealed as a potential cosmeceutical agent due to its antioxidation and anti-melanogenic activity in association with L-anserine and L-carnosine composition and biomolecular regulating ability. Therefore, further studies and development should be considered to support the utilization of anserine/carnosine-rich chicken extract in the cosmetic industry for economic value creation and sustainability.

Novel angiotensin-converting enzyme and pancreatic lipase oligopeptide inhibitors from fermented rice bran

This study determined the inhibitory activity of oligopeptides against angiotensin-converting enzyme (ACE) and pancreatic lipase through in vitro tests, molecular docking, and enzyme inhibition. The results showed that the IC₅₀ of GLLGY, HWP, and VYGF for ACE inhibition was 1 mg/mL, and the IC₅₀ of HWP for pancreatic lipase was 3.95 mg/mL. Molecular docking revealed that the binding energies between GLLGY, HWP, and VYGF and ACE were –9.0, –8.4, and –9.2 kcal/mol, respectively. The binding free energy between HWP and pancreatic lipase was –7.3 kcal/mol. GLLGY, HWP, and VYGF inhibited ACE compentitively. HWP inhibited pancreatic lipase through non-competition. in vitro simulated gastrointestinal digestion, the three oligopeptides still had inhibitory activity and low toxicity. The results revealed that the peptides GLLGY, HWP, and VYGF may be suitable candidates for further research on ACE inhibition, and HWP may be a suitable candidate for studying pancreatic lipase inhibition.

Efficient screening of pancreatic lipase inhibitors from cod meat hydrolysate through ligand fishing strategy

Obesity has become an increasingly serious public health problem. Pancreatic lipase (PL) is identified as a ideal target for the prevention and treatment of obesity. Orlistat, the only approved PL inhibitor (PLI), is a powerful weight loss drug but has many side effects. Therefore, there is an urgent need to discover powerful PLIs with high safety. Protein hydrolysate has been demonstrated to be a treasure trove of PLIs, but recognizing responsible functional peptides from them is like looking for a needle in a haystack. In this work, we synthesized and optimized a PL ligand fishing model (PLLFM) using magnetic nanoparticles (MNPs), then PLLFM was used to quickly fish out potential PLIs from the Cod meat hydrolysate (CMH). Finally, two new PLIs, GSPPPSG and KLEGDLK were identified with IC₅₀ of 0.60 and 1.08 mg/mL, respectively. The Lineweaver-Burk diagram showed that GSPPPSG is a non-competitively dominant mixed-type PLI, whereas KLEGDLK is a competitive inhibitory-type PLI. Moreover, molecular docking suggested that both peptides can stably bind to the key amino acid residues of the PL active site, mainly through hydrogen bonding, hydrophobic, and electrostatic interactions. In general, we not only established a method to rapidly fish out potential PLIs from protein hydrolysate, but also provided safe and efficient lead compounds for the development of novel diet foods or drugs.