Identification of two novel peptides with antioxidant activity and their potential in inhibiting amyloid-β aggregation in vitro

Exploring the Mechanisms of Anti-Aβ42 Aggregation Activity of Walnut-derived Peptides using Transcriptomics and Proteomics in vitro

Inhibiting β-amyloid (Aβ) aggregation is of significance in finding potential candidates for Alzheimer’s disease (AD) treatment. Accumulating evidence suggests that nutrition is important for improving cognition and reducing AD risk. Walnut has been widely used as a functional food for brain health; however the underlying mechanisms remain unknown. Here, we investigated the molecular level alteration in Arctic mutant Aβ42 induced aggregation cell model by RNA-seq and iTRAQ approaches after walnut-derived peptides Pro-Pro-Lys-Asn-Trp (PW5) and Trp-Pro-Pro-Lys-Asn (WN5) interventions. PW5 or WN5 could significantly decrease abnormal Aβ42 aggregates. However, resultant alterations in transcriptome (substantially unchanged) were inconsistent with proteomic data (marked change). Proteomic analysis revealed 184 and 194 differentially expressed proteins unique to PW5 and WN5 treatment, respectively, for inhibiting Aβ42 protein production or increasing protein degradation via the mismatch repair pathways. Our study provides new insights into the effectiveness of food-derived peptides for anti-Aβ42 aggregation in AD.

A biotechnological approach for the production of branched chain amino acid containing bioactive peptides to improve human health: A review

Improper nutrition provokes many types of chronic diseases and health problems, which consequently are associated with particularly high costs of treatments. Nowadays, consumer's interest in healthy eating is shifting towards specific foods or food ingredients. As a consequence, bioactive peptides as a promising source of health promoting food additives are currently an intensely debated topic in research. Process design is still on its early stages and is significantly influenced by important preliminary decisions. Thus, parameters like peptide bioactivity within the product, selection of the protein source, enzyme selection for hydrolysis, peptide enrichment method, as well as stability of the peptides within the food matrix and bioavailability are sensitive decision points, which have to be purposefully coordinated, as they are directly linked to amino acid content and structure properties of the peptides. Branched chain amino acids (BCAA) are essential components for humans, possessing various important physiologic functions within the body. Incorporated within peptide sequences, they may induce dual functions, when used as nutraceuticals in functional food, thus preserving the foodstuff and prevent several widespread diseases. Furthermore, there is evidence that consuming this peptide-class can be a nutritional support for elderly people or improve human health to prevent diseases caused by incorrect nutrition. Based on the knowledge about the role of BCAA within various peptide functions, discussed in the review, special attention is given to different approaches for systematic selection of the protein source and enzymes used in hydrolysis, as well as suitable peptide enrichment methods, thereby showing current trends in research.

A new dual-peptide strategy for enhancing antioxidant activity and exploring the enhancement mechanism

The development of a new generation antioxidant peptides with high free radical scavenging rates is highly desirable, but remains a great challenge.