Review on Extraction, Modification, and Synthesis of Natural Peptides and Their Beneficial Effects on Skin.

Peptides, functional nutrients with a size between those of large proteins and small amino acids, are easily absorbed by the human body. Therefore, they are seeing increasing use in clinical medicine and have revealed immunomodulatory and anti-inflammatory properties which could make them effective in healing skin wounds. This review sorted and summarized the relevant literature about peptides during the past decade. Recent works on the extraction, modification and synthesis of peptides were reviewed. Importantly, the unique beneficial effects of peptides on the skin were extensively explored, providing ideas for the development and innovation of peptides and laying a knowledge foundation for the clinical application of peptides.

Hericium caput-medusae (Bull.:Fr.) Pers. fermentation concentrate polysaccharides improves intestinal bacteria by activating chloride channels and mucus secretion.

ETHNOPHARMACOLOGICAL RELEVANCE: As a traditional edible fungus in China and many other Asian countries, Hericium caput-medusae (Bull. Fr.) Pers. is widely used to improve the health of the gastrointestinal tract. For example, the drug "Weilexin Granules" is mainly composed of H. caput-medusae (Bull. Fr.) Pers. fermentation concentrate. However, the mechanism of action remains to be elucidated. AIMS OF THE STUDY: The purpose of this study was to assess whether polysaccharides from H. caput-medusae (Bull. Fr.) Pers. fermentation concentrate (HFP) exerts a gut protective effect and a regulatory effect on the intestinal microbiota through the chloride channels and mucus secretion. MATERIALS AND METHODS: HFP was extracted, characterized and different concentrations of HFP (100, 200, 400 mg/kg) were administered to mice for 14 days. The changes in gut microbiota were observed via 16S high throughput sequencing. Short-chain fatty acids (SCFAs) was detected by GC-MS. AB-PAS staining was used to observe the secretion of mucus. The chloride channel activity and protein expression were verified by short-circuit current measurement and Western blot. RESULTS: HFP regulated the abundance of gut microbiota in mice, with increased levels of Ruminococcaceae and Lachnospiraceae and reduced proportions of Staphylococcus and Enterobacter. HFP enhanced mucus volume as well as increased intestinal fluid secretion by activating the chloride channels. In addition, short-circuit current experiments also proved that HFP activates Cl⁻ currents targeting cystic fibrosis transmembrane conductance regulator (CFTR) and Anoamin1 (ANO1). CONCLUSION: In conclusion, HFP might increase intestinal fluid secretion by promoting Cl⁻ secretion, which in turn advanced mucus hydration as well as regulated gut microbiota to improve intestinal health. Therefore, H. caput-medusae (Bull. Fr.) Pers. could be potentially used in the regulation of intestinal secretion and microbes.

Effect of Flammulina velutipes polysaccharides on endoplasmic reticulum stress-mediated apoptosis by activating PLC-IP3 pathway in HepG2 cells.

Flammulina velutipes polysaccharides (FVP) have been proven to induce apoptosis in HepG2 cells. It is well known that endoplasmic reticulum stress (ERS) is involved in apoptosis. However, ERS mediates FVP-induced apoptosis in HepG2 cells remains unclear. In our study, the results indicated that FVP caused ERS in HepG2 cells. They showed that FVP were water-soluble polysaccharides with the weight average molecular weight of 1972 kDa, which were mainly composed of mannose, gluconic acid, glucose, galactose, xylose and fructose in a molar ratio of 6.6 : 1.3 : 79.9 : 7.4 : 3.4 : 1.5. After FVP treatment, the expression levels of genes and proteins related to ERS were upregulated. The inhibition of ERS by 4-phenylbutyric acid (4-PBA) pretreatment could significantly reduce the role of FVP in inducing apoptosis. We further found the results of immunofluorescence and flow cytometry showing that Ca2+ in the ERS leaked out, and the intracellular Ca2+ concentration increased after FVP treatment. The pretreatment with the phospholipase C (PLC) inhibitor U73122 proved that FVP caused excessive intracellular Ca2+ concentration by activating the phospholipase C-inositol-1,4,5-triphosphate (PLC-IP3) pathway, resulting in ERS, and ultimately leading to apoptosis. In summary, our results indicated that FVP induced ERS-mediated apoptosis by activating PLC-IP3 pathway in HepG2 cells. PRACTICAL APPLICATION: This work may suggest that FVP could be used as an adjuvant therapy to anticancer drugs, providing new application prospects and possibilities.

Feed Supplemented with Aronia melanocarpa (AM) Relieves the Oxidative Stress Caused by Ovulation in Peak Laying Hens and Increases the Content of Yolk Precursors.

The continuous ovulation of laying hens during the peak period is likely to cause oxidative stress, resulting in a reduction in the laying cycle over time. The aim of this study was to evaluate the antioxidant effects of Aronia melanocarpa (AM) in the diet and its effect on the yolk precursor content caused by ovulation in laying hens during the peak period. A total of 300 25-week-old Roman brown laying hens were randomly divided into five groups with six replicates in each group, 10 in each replicate. The control group was fed a basal diet, the positive control group was fed a Vitamin C (VC) plus basal diet, and the experimental group was fed 1%, 4%, and 7% doses of AM plus diet according to the principle of energy and nitrogen requirements, which lasted eight weeks. At the end of the study, the egg quality, biochemical, and antioxidant markers, as well as mRNA and protein expressions, were evaluated to determine the potential signaling pathways involved. Results showed that the addition of AM to the feed increased the weight of laying hens at the peak of egg production and improved egg quality. The biochemical markers, as well as the antioxidant parameters in the serum, liver, and ovarian tissues, were ameliorated. The gene and protein expression of recombinant kelch-like ECH-associated protein 1 (Keap1) in the liver and ovarian tissues was decreased, while nuclear factor erythroid-2 related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) expression was increased. The feed supplemented with AM also increased the estrogen contents and lipid parameters, as well as the gene and protein expressions related to the yolk precursor. Feed supplemented with AM could improve the egg quality and the oxidative stress caused by the ovulation process of laying hens during the peak egg production period by activating the Keap1/Nrf2 signaling pathway. These results suggest that the feed supplemented with 1% AM and 4% AM can improve egg production in peak laying hens.