Therapeutic Perspectives of Food Bioactive Peptides: A Mini Review

Explore peptides extracted from gliadin hydrolysates suppressing BACE1 activity and restraining Aβ protein deposition

Alzheimer's Disease (AD) constitutes approximately 70 % of dementia cases and is the most prevalent form of dementia. Current therapeutic options, including acetylcholinesterase inhibitors and N-methyl d-aspartate (NMDA) receptor antagonists, provide symptomatic relief but do not cure the disease and often come with side effects. The primary pathological features of AD are amyloid plaques and neurofibrillary tangles, with amyloid plaques formed by the abnormal accumulation of Amyloid-β (Aβ). BACE1 (β-site APP-cleaving enzyme 1), a β-secretase, is a key initiator in amyloidosis. Previous research has shown that G-Bro hydrolysate, produced from the bromelain hydrolysis of gliadin, has optimal BACE1 inhibitory efficiency. This study employs G-Bro hydrolysate for nano UHPLC-ESI Q-TOF mass spectrometry to identify peptide fragment sequences and conducts BACE1 inhibition assays to isolate the most effective peptide, VR-peptide. Using the N2a/PS/APP cell model, we explored the impact of chemically synthesized VR-peptide on BACE1 protein expression, the secretion of soluble APP (sAPP), and levels of Aβ and intracellular Aβ1-42. Results demonstrate that VR-peptide achieves a BACE1 inhibitory rate of 63.8 % and reduces BACE1 expression by over 90 % in comparison with untreated N2a/PS/APP cells. It shifts the balance between extracellular Aβ monomers and aggregates, favoring monomer formation and decreasing intracellular Aβ1-42 levels by over 56 %, underscoring its neuroprotective potential. In conclusion, VR-peptide exhibits promise as a BACE1 inhibitor and a preventive agent against Alzheimer's disease. Derived from hydrolyzed cereal foods, it could be effectively paired with a suitable drug delivery system for enhanced neuronal penetration, paving the way for neuroprotective peptide products targeting Alzheimer's disease.

PeposX-Exhaust: A lightweight and efficient tool for identification of short peptides

Short peptides have become the focus of recent research due to their variable bioactivities, good digestibility and wide existences in food-derived protein hydrolysates. However, due to the high complexity of the samples, identifying short peptides still remains a challenge. In this work, a tool, named PeposX-Exhaust, was developed for short peptide identification. Through validation with known peptides, PeposX-Exhaust identified all the submitted spectra and the accuracy rate reached 75.36%, and the adjusted accuracy rate further reached 98.55% when with top 5 candidates considered. Compared with other tools, the accuracy rate by PeposX-Exhaust was at least 70% higher than two database-search tools and 15% higher than the other two de novo-sequencing tools, respectively. For further application, the numbers of short peptides identified from soybean, walnut, collagen and bonito protein hydrolysates reached 1145, 628, 746 and 681, respectively. This fully demonstrated the superiority of the tool in short peptide identification.

Evaluation of the Multifunctionality of Soybean Proteins and Peptides in Immune Cell Models

Inflammatory and oxidative processes are tightly regulated by innate and adaptive immune systems, which are involved in the pathology of a diversity of chronic diseases. Soybean peptides, such as lunasin, have emerged as one of the most hopeful food-derived peptides with a positive impact on health. The aim was to study the potential antioxidant and immunomodulatory activity of a lunasin-enriched soybean extract (LES). The protein profile of LES was characterized, and its behavior under simulated gastrointestinal digestion was evaluated. Besides its in vitro radical scavenging capacity, LES and lunasin's effects on cell viability, phagocytic capacity, oxidative stress, and inflammation-associated biomarkers were investigated in both RAW264.7 macrophages and lymphocytes EL4. Lunasin and other soluble peptides enriched after aqueous solvent extraction partially resisted the action of digestive enzymes, being potentially responsible for the beneficial effects of LES. This extract scavenged radicals, reduced reactive oxygen species (ROS) and exerted immunostimulatory effects, increasing nitric oxide (NO) production, phagocytic activity, and cytokine release in macrophages. Lunasin and LES also exerted dose-dependent immunomodulatory effects on EL4 cell proliferation and cytokine production. The modulatory effects of soybean peptides on both immune cell models suggest their potential protective role against oxidative stress, inflammation, and immune response-associated disorders.

Recent research progress of biologically active peptides

With the rapid development of molecular biology and biochemical technology, great progress has been made in the study of peptides. Peptides are easy to digest and absorb, with lowering of blood pressure and cholesterol, improving immunity, regulating hormones, antibacterial, and antiviral effects. Peptides also have physiological regulation and biological metabolism functions with applications in the fields of feed production and biomedical research. In the future, the research focus of bioactive peptides will focus on their efficient preparation and application. This article introduces a comprehensive review of the types, synthesis, functionalization, and bio-related applications of bioactive peptides. For this aim, we introduced in detail various biopeptides and then presented the production methods of bioactive peptides, such as enzymatic synthesis, microbial fermentation, chemical synthesis, and others. The applications of bioactive peptides for anticancers, immune therapy, antibacterial, and other applications have been introduced and discussed. And discussed the development prospects of biologically active peptides.

Royal Jelly Proteins and Their Derived Peptides: Preparation, Properties, and Biological Activities

Royal jelly, also called bee milk, is a source of high-quality proteins. Royal jelly proteins serve as not only a rich source of essential amino acids and functional donors but also an excellent substrate for preparing bioactive peptides. Most naturally occurring bioactive peptides in royal jelly are antibacterial, while peptides derived from proteolytic reactions are shown to exert antihypertensive, antioxidative, and anti-aging activities. Further studies are warranted to characterize the functional properties of major royal jelly proteins and peptides, to explore the preparation of bioactive peptides and the potential novel activities, to improve their bioavailability, to enhance the production efficiency for commercial availability, and finally to open up new applications for royal jelly as a functional food and potential therapeutic agent.

Plant Bioactive Peptides: Current Status and Prospects Towards Use on Human Health

Large numbers of bioactive peptides with potential applications in protecting against human diseases have been identified from plant sources. In this review, we summarized recent progress in the research of plant-derived bioactive peptides, encompassing their production, biological effects, and mechanisms. This review focuses on antioxidant, antimicrobial, antidiabetic, and anticancer peptides, giving special attention to evidence derived from cellular and animal models. Studies investigating peptides with known sequences and well-characterized peptidic fractions or protein hydrolysates will be discussed. The use of molecular docking tools to elucidate inter-molecular interactions between bioactive peptides and target proteins is highlighted. In conclusion, the accumulating evidence from in silico, in vitro and in vivo studies to date supports the envisioned applications of plant peptides as natural antioxidants as well as health-promoting agents. Notwithstanding, much work is still required before the envisioned applications of plant peptides can be realized. To this end, future researches for addressing current gaps were proposed.