The wound healing potential of collagen peptides derived from the jellyfish Rhopilema esculentum.

PURPOSE: Wound represents a major health challenge as they consume a large amount of healthcare resources to improve patient's quality of life. Many scientific studies have been conducted in search of ideal biomaterials with wound-healing activity for clinical use and collagen has been proven to be a suitable candidate biomaterial. This study intended to investigate the wound healing activity of collagen peptides derived from jellyfish following oral administration. METHODS: In this study, collagen was extracted from the jellyfish--Rhopilema esculentum using 1% pepsin. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and fourier transform infrared (FTIR) were used to identify and determine the molecular weight of the jellyfish collagen. Collagenase II, papain and alkaline proteinase were used to breakdown jellyfish collagen into collagen peptides. Wound scratch assay (in vitro) was done to determine migration potential of human umbilical vein endothelial cells (HUVEC) covering the artificial wound created on the cell monolayer following treatment with collagen peptides. In vivo studies were conducted to determine the effects of collagen peptides on wound healing by examining wound contraction, re-epithelialization, tissue regeneration and collagen deposition on the wounded skin of mice. Confidence level (p < 0.05) was considered significant using GraphPad Prism software. RESULTS: The yield of collagen was 4.31%. The SDS-PAGE and FTIR showed that extracted collagen from jellyfish was type I. Enzymatic hydrolysis of this collagen using collagenase II produced collagen peptides (CP1) and hydrolysis with alkaline proteinase/papain resulted into collagen peptides (CP2). Tricine SDS-PAGE revealed that collagen peptides consisted of protein fragments with molecular weight <25 kDa. Wound scratch assay showed that there were significant effects on the scratch closure on cells treated with collagen peptides at a concentration of 6.25 µg/mL for 48 h as compared to the vehicle treated cells. Overall treatment with collagen peptide on mice with full thickness excised wounds had a positive result in wound contraction as compared with the control. Histological assessment of peptides treated mice models showed remarkable sign of re-epithelialization, tissue regeneration and increased collagen deposition. Immunohistochemistry of the skin sections showed a significant increase in ß-fibroblast growth factor (ß-FGF) and the transforming growth factor-ß1 (TGF-ß1) expression on collagen peptides treated group. CONCLUSION: Collagen peptides derived from the jellyfish-Rhopilema esculentum can accelerate the wound healing process thus could be a therapeutic potential product that may be beneficial in wound clinics in the future.

Deoxycholic acid inhibits the growth of BGC-823 gastric carcinoma cells via a p53­mediated pathway.

The aim of the present study was to investigate the effects of deoxycholic acid (DCA) on BGC­823 human gastric carcinoma cells and to explore the possible mechanisms underlying any such effects. Cell proliferation was detected using a 3­(4,5­Dimethylthiazol­2­yl)­2,5­diphenyl tetrazolium bromide assay, cell morphology was observed by inverted microscopy, and cell cycle progression and the mitochondrial membrane potential were analyzed using flow cytometry. The expression of Bcl­2, Bax, p53, Cyclin D1 and cyclin­dependent kinase (CDK)2 proteins in BGC­823 cells was analyzed with western blotting. The results demonstrated that DCA significantly inhibited cell growth, and that the cell cycle was arrested at the G1 phase. DCA was also shown to induce BGC­823 cell apoptosis, which was associated with the collapse of the mitochondrial membrane potential. The mitochondria­dependent pathway was activated via an increase in the ratio of Bax:Bcl­2 in BGC­823 cells. In addition, the expression of p53, cyclin D1 and CDK2 was altered following DCA treatment. These results suggest that DCA induces apoptosis in gastric carcinoma cells through activation of an intrinsic mitochondrial­dependent pathway, in which p53 is involved.