Elastin hydrolysate has apparent beneficial effects, and the food-derived peptide prolyl-glycine (Pro-Gly) is present in human blood after oral ingestion. Following ingestion of elastin hydrolysate (10 g/60 kg body weight) by healthy human volunteers, peripheral blood was used to prepare plasma samples from which peptides were extracted by solid phase extraction and fractionated by size-exclusion chromatography (SEC). Peptides in the SEC fractions were derivatized with phenyl isothiocyanate (PITC) and resolved by reversed phase (RP)-HPLC. Pro-Gly was the major food-derived elastin peptide, reaching a maximum (18 μM) at 30 min after ingestion, and decreasing to approximately 20% at 4 h after ingestion. Finally, in cell culture, levels of Pro-Gly in the medium above 0.1 μg/mL significantly enhanced elastin synthesis of normal human dermal fibroblasts (NHDF) without affecting the rate of cell proliferation.

We obtained pure elastin peptides from bovine ligamentum nuchae, porcine aorta, and bonito bulbus arteriosus. The inhibitory activity of these elastin peptides on platelet aggregation induced by collagen and the migratory and proliferative responsivenesses of human skin fibroblasts to these elastin peptides were examined. All of bonito, bovine, and porcine elastin peptides found to inhibit platelet aggregation, but bonito elastin peptides showed a higher inhibitory activity than bovine and porcine elastin peptides did. All elastin peptides enhanced the proliferation of fibroblasts 3.5- to 4.5-fold at a concentration of 10 µg/ml. Bovine and porcine elastin peptides stimulated the migration of fibroblasts, with the optimal response occurring at 10(-1) µg/ml, while maximal response was at 10(2) µg/ml for bonito elastin peptides. Furthermore, pretreatment of fibroblasts by lactose depressed their ability to migrate in response to all elastin peptides, suggesting the involvement of elastin receptor in cell response. These results suggest that both mammalian and piscine elastin peptides can be applied as useful biomaterials in which elasticity, antithrombotic property, and the enhancement of cell migration and proliferation are required.

Therefore, elastin hydrolysate activates human skin fibroblasts and has beneficial effects on skin conditions.

No abstract

KEY WORDS: amino acid, bulbus arteriosus, collagen, desmosine, elastin, isodesmosine, skin.Collagen, hyaluronic acid, and elastin are contained in the extracellular matrix. They function in metabolism, multiplication, differentiation, and maintenance of cells in vivo . 1 Elastin is a protein found in the lung, skin, ligaments, and arteries. It has been shown to be important as a construction material for the cell, like collagen, and is used in diverse fields including cosmetics, food, and medicine. Elastin for commercial use has been produced from bovine ligaments; however, bovine spongiform encephalopathy (BSE) has led to concern regarding the use of elastin of bovine origin. However, elastin from fish raw materials is expected to maintain social acceptability since fishes from natural sources are free from BSE.We attempted to manufacture elastin peptides from aquatic resources such as fish bulbus arteriosus and skin, which were excised easily from fish; however, they have been rarely used industrially and are discarded. The properties of these peptides were evaluated by the fluorescence intensity and the amino acid composition.Raw materials were selected from yellowtail Seriola quinqueradiata (2.0 kg body weight), skipjack Katsuwonus pelamis (2.2 kg), bluefin tuna Thunnus thynnus (1.8 kg), salmon Salmo salar (2.0 kg), and walleye pollock Theragra chalcogramma (0.7 kg). These species have constantly supported major fisheries in Japan.First, tissue section of the bulbus arteriosus and skin from these fishes was performed by routine histological methods to confirm the elastin distribution in the organ. They were fixed in 10% formaldehyde in 0.1 M sodium phosphate at pH 7.0, then materials were embedded in paraffin, sectioned, and stained by Elastica Van Gieson (EVG) stain. 2 Tissues from the bulbus arteriosus and skin, and also dark, heart, and ordinary muscle, intestine, kidney, liver, ovary, pyloric cecum, spleen, and stomach from fresh fish were analyzed for amino acid desmosine (Des) and isodesmosine (Ide) contents. The tissues were washed with 1% NaCl and cut into small pieces. The pieces were lyophilized, then tissue samples were hydrolyzed in 6 M HCl under nitrogen at 110 ° C for 20 h in sealed glass tubes. The hydrolyzates were dried and diluted in 0.02 M HCl. Amino acid analysis was carried out on a JLC-500/V instrument (JEOL, Tokyo, Japan) with the buffer system modified for separation of free amino acids.Second, soluble elastin peptide was prepared at the commercial production scale from bulbus arteriosus and skin by the following methods. Bulbus arteriosus (3.0 g) were dissected from fresh yellowtail (4.5 kg average body weight), which was obtained in Kumamoto. They were washed and kept frozen at − 20 ° C until use. Thawed bulbus arteriosus (100 kg) was defatted in 0.01 M NaOH at 4 ° C, and washed with distilled water. To remove the collagen, the materials were boiled at 95 ° C for 5 min and ground mechanically. The fragments were hydrolyzed at 50 ° C for 8 h at pH 8.5 by two kinds of commercial protea...