Influence of collagen peptide supplementation on visible signs of skin and nail health and -aging in an East Asian population: A double blind, randomized, placebo-controlled trial.

BACKGROUND: A healthy skin provides protection against intrinsic and extrinsic factors. Skin aging is characterized by structural and morphological alterations affecting skin health, integrity, and functionality, resulting in visible aging signs. AIM: The primary objective of this study was to assess the effect of a collagen peptide dietary supplement on skin aging in the East Asian population. METHODS: Eighty-five healthy women, aged from 43 to 65 years old, were randomly assigned to the collagen supplement (CP, 5 g) or placebo (maltodextrin, 5 g) group. To standardize daily skin care, the volunteers in both groups used a specific face cream for 28 days prior to and throughout the supplementation period, creating an equal baseline for the assessment of the efficacy of CP on several skin parameters. At baseline, day 28 and day 84, the following hallmarks of skin and nail aging were assessed: dermis density, skin moisture and elasticity, wrinkle visibility, beauty perception, and nail color. RESULTS: After 84 days, a significant improvement of dermis density and skin moisture was observed in the collagen peptides group compared to the placebo group. Positive effects on skin elasticity, wrinkle visibility, nail color, and overall beauty perception were already observed within 28 days of supplementation in the CP group, while the same effects in the placebo group were only observed after 84 days. CONCLUSION: Taken together, these results show that, in addition to a standardized skin care, daily supplementation with 5 g of collagen peptides positively affects visible signs of skin and nail aging in the East Asian population.

Absorption of bioactive peptides following collagen hydrolysate intake: a randomized, double-blind crossover study in healthy individuals.

Background: Collagen hydrolysates (CH) in functional foods and supplements are dietary sources of amino acids (AAs) and di-and tripeptides linked to various health benefits. This study aimed to investigate the single-dose bioavailability of skin- and hide-derived CH from fish, porcine and bovine origin with different molecular weights (bovine 2,000 and 5,000 Da). Methods: A randomized, double-blind crossover clinical study was performed with healthy volunteers assessing the plasma concentration of free and peptide-bound hydroxyproline (Hyp) as well as selected peptides reported to be abundantly present in collagen. Results: The pharmacokinetic endpoints demonstrated comparable uptake of free Hyp from all CH. A higher amount of total compared to free Hyp indicated the uptake of substantial amounts of Hyp-containing di- or tripeptides. Conclusion: Independently of source and molecular weight, all CH yielded relevant plasma concentrations of the investigated metabolites. Larger studies are needed to estimate an ideal level of selected circulating metabolites needed to trigger distinct physiological reactions in target tissues.

Coral calcification under daily oxygen saturation and pH dynamics reveals the important role of oxygen.

Coral reefs are essential to many nations, and are currently in global decline. Although climate models predict decreases in seawater pH (∼0.3 units) and oxygen saturation (∼5 percentage points), these are exceeded by the current daily pH and oxygen fluctuations on many reefs (pH 7.8-8.7 and 27-241% O2 saturation). We investigated the effect of oxygen and pH fluctuations on coral calcification in the laboratory using the model species Acropora millepora. Light calcification rates were greatly enhanced (+178%) by increased seawater pH, but only at normoxia; hyperoxia completely negated this positive effect. Dark calcification rates were significantly inhibited (51-75%) at hypoxia, whereas pH had no effect. Our preliminary results suggest that within the current oxygen and pH range, oxygen has substantial control over coral growth, whereas the role of pH is limited. This has implications for reef formation in this era of rapid climate change, which is accompanied by a decrease in seawater oxygen saturation owing to higher water temperatures and coastal eutrophication.

Red light represses the photophysiology of the scleractinian coral Stylophora pistillata.

Light spectrum plays a key role in the biology of symbiotic corals, with blue light resulting in higher coral growth, zooxanthellae density, chlorophyll a content and photosynthesis rates as compared to red light. However, it is still unclear whether these physiological processes are blue-enhanced or red-repressed. This study investigated the individual and combined effects of blue and red light on the health, zooxanthellae density, photophysiology and colouration of the scleractinian coral Stylophora pistillata over 6 weeks. Coral fragments were exposed to blue, red, and combined 50/50% blue red light, at two irradiance levels (128 and 256 µmol m(-2) s(-1)). Light spectrum affected the health/survival, zooxanthellae density, and NDVI (a proxy for chlorophyll a content) of S. pistillata. Blue light resulted in highest survival rates, whereas red light resulted in low survival at 256 µmol m(-2) s(-1). Blue light also resulted in higher zooxanthellae densities compared to red light at 256 µmol m(-2) s(-1), and a higher NDVI compared to red and combined blue red light. Overall, our results suggest that red light negatively affects the health, survival, symbiont density and NDVI of S. pistillata, with a dominance of red over blue light for NDVI.

Tuning of collagen triple-helix stability in recombinant telechelic polymers.

The melting properties of various triblock copolymers with random coil middle blocks (100-800 amino acids) and triple helix-forming (Pro-Gly-Pro)(n) end blocks (n = 6-16) were compared. These gelatin-like molecules were produced as secreted proteins by recombinant yeast. The investigated series shows that the melting temperature (T(m)) can be genetically engineered to specific values within a very wide range by varying the length of the end block. Elongation of the end blocks also increased the stability of the helices under mechanical stress. The length-dependent melting free energy and T(m) of the (Pro-Gly-Pro)(n) helix appear to be comparable for these telechelic polymers and for free (Pro-Gly-Pro)(n) peptides. Accordingly, the T(m) of the polymers appeared to be tunable independently of the nature of the investigated non-cross-linking middle blocks. The flexibility of design and the amounts in which these nonanimal biopolymers can be produced (g/L range) create many possibilities for eventual medical application.

Secreted production of collagen-inspired gel-forming polymers with high thermal stability in Pichia pastoris.

Previously, we have shown that gel-forming triblock proteins, consisting of random coil middle blocks and trimer-forming (Pro-Gly-Pro)(9) end blocks, are efficiently produced and secreted by the yeast Pichia pastoris. These end blocks had a melting temperature (T(m)) of ∼41°C (at 1.1 mM of protein). The present work reveals that an increase of T(m) to ∼74°C, obtained by extension of the end blocks to (Pro-Gly-Pro)(16), resulted in a five times lower yield and partial endoproteolytic degradation of the protein. A possible cause could be that the higher thermostability of the longer (Pro-Gly-Pro)(16) trimers leads to a higher incidence of trimers in the cell, and that this disturbs secretion of the protein. Alternatively, the increased length of the proline-rich (Pro-Gly-Pro)(n) domain may negatively influence ribosomal translation, or may result in, for example, hydrophobic aggregation or membrane-active behavior owing to the greater number of closely placed proline residues. To discriminate between these possibilities, we studied the production of molecules with randomized end blocks that are unable to form triple helices. The codon- and amino acid composition of the genes and proteins, respectively, remained unchanged. As these nontrimerizing molecules were secreted intact and at high yield, we conclude that the impaired secretion and partial degradation of the triblock with (Pro-Gly-Pro)(16) end blocks was triggered by the occurrence of intracellular triple helices. This degradation was overcome by using a yapsin 1 protease disruptant, and the intact secreted polymer was capable of forming self-supporting gels of high thermal stability.