Dietary bovine lactoferricin improved gut microflora, benefited intestinal mucosal morphology and inhibited circular cytokines delivery in 21-day weaned piglets

Meta-Analysis for Correlating Structure of Bioactive Peptides in Foods of Animal Origin with Regard to Effect and Stability

Amino acid (AA) sequences of 807 bioactive peptides from foods of animal origin were examined in order to correlate peptide structure with activity (antihypertensive, antioxidative, immunomodulatory, antimicrobial, hypolipidemic, antithrombotic, and opioid) and stability in vivo. Food sources, such as milk, meat, eggs, and marine products, show different frequencies of bioactive peptides exhibiting specific effects. There is a correlation of peptide structure and effect, depending on type and position of AA. Opioid peptides contain a high percentage of aromatic AA residues, while antimicrobial peptides show an excess of positively charged AAs. AA residue position is significant, with those in the first and penultimate positions having the biggest effects on peptide activity. Peptides that have activity in vivo contain a high percentage (67%) of proline residues, but the positions of proline in the sequence depend on the length of the peptide. We also discuss the influence of processing on activity of these peptides, as well as methods for predicting release from the source protein and activity of peptides.

A review of the design and modification of lactoferricins and their derivatives

Lactoferricin (Lfcin), a multifunction short peptide with a length of 25 residues, is derived from the whey protein lactoferrin by acidic pepsin hydrolysis. It has potent nutritional enhancement, antimicrobial, anticancer, antiviral, antiparasitic, and anti-inflammatory activities. This review describes the research advantages of the above biological functions, with attention to the molecular design and modification of Lfcin. In this examination of design and modification studies, research on the identification of Lfcin active derivatives and crucial amino acid residues is also reviewed. Many strategies for Lfcin optimization have been studied in recent decades, but we mainly introduce chemical modification, cyclization, chimera and polymerization of this peptide. Modifications such as incorporation of D-amino acids, acetylation and/or amidation could effectively improve the activity and stability of these compounds. Due to their wide array of bio-functions and applications, Lfcins have great potential to be developed as biological agents with multiple functions involved with nutritional enhancement, as well as disease preventive and therapeutic effects.

Antimicrobial Activity of Lactoferrin-Related Peptides and Applications in Human and Veterinary Medicine

Antimicrobial peptides (AMPs) represent a vast array of molecules produced by virtually all living organisms as natural barriers against infection. Among AMP sources, an interesting class regards the food-derived bioactive agents. The whey protein lactoferrin (Lf) is an iron-binding glycoprotein that plays a significant role in the innate immune system, and is considered as an important host defense molecule. In search for novel antimicrobial agents, Lf offers a new source with potential pharmaceutical applications. The Lf-derived peptides Lf(1-11), lactoferricin (Lfcin) and lactoferrampin exhibit interesting and more potent antimicrobial actions than intact protein. Particularly, Lfcin has demonstrated strong antibacterial, anti-fungal and antiparasitic activity with promising applications both in human and veterinary diseases (from ocular infections to osteo-articular, gastrointestinal and dermatological diseases).