Proline-rich Peptide
Based of the study of Janusz and Zablocka (2010) a proline-rich polypeptide complex (PRP), subsequently called Colostrinin(CLN), was first isolated from ovine colostrum, was shown to possess immunoregulatory properties, including effects on the maturation and differentiation of murine thymocytes and humoral and cellular immune responses, both in vivo and in vitro. PRP seems to restore balance in cellular immune functions and is not species specific. PRP is a complex of peptides of molecular masses ranging from 500 to 3000 Da. The polypeptide contains 25% proline and 40% hydrophobic amino acids. PRP shows a regulatory activity in cytokine (IFN, TNF-alpha, IL-6, IL-10) induction and possesses the ability to inhibit the overproduction of oxygen reactive species and nitric oxide. Besides its immunoregulatory activity, PRP also showed psychotropic properties, improving cognitive activity and behavior of old rats, humans, and chickens. The properties of PRP prompted the authors to propose the complex for the treatment neurodegenerative disorders. Beneficial effects of PRP/Colostrinin were shown for the first time in double-blind placebo-controlled trials and long-term open-label studies. Their study results were confirmed in multicenter clinical trials. A very important property of PRP/Colostrinin is the prevention of Abeta aggregation and the disruption of already existing aggregates. The same properties were expressed by one of PRP's components, a nonapeptide (NP). Moreover, PRP modulates neurite outgrowth, suppresses uncontrolled activation of cells, reduces 4-HNE-mediated cellular damage, and modulates expression in cellular redox regulation, cell proliferation, and differentiation. Its biological response modifying activity can play an important role in its use in the treatment of Alzheimer's disease.
Colostrinin was originally identified by scientists working in Poland in the 1970s. Colostrinin is derived from colostrum, which is present in the pre-milk fluid produced from mammary glands in the first few days after parturition. It is also known as proline-rich polypeptides, since sequence analysis of the peptides present in this mixture reveals an unusually high proportion of this amino acid residue. The amino acid compositions of Colostrinin from ovine, bovine, and human colostrum are very similar. Colostrinin was first characterized in animal and in-vitro studies as a substance that generally stimulates the immune response. Such an immunomodulatory action may be important in the treatment of a variety of diseases and is consistent with the beneficial effect of colostrum in promoting the development of the immune system in newborn mammals.