Duck Egg White-Derived Peptide VSEE (Val-Ser-Glu-Glu) Regulates Bone and Lipid Metabolisms by Wnt/β-Catenin Signaling Pathway and Intestinal Microbiota

Scope: Val-Ser-Glu-Glu (VSEE), identified from duck egg white peptides, has been proven to facilitate calcium absorption in a previous study. Since prevention of osteoporosis is important, it might act as a potential cofactor in osteoporosis prevention. Therefore, the aim of this study is to investigate the regulation of VSEE on osteoporosis and abnormal lipid metabolisms.

Methods and results: MC3T3-E1 cell and ovariectomized (OVX) rat model are used to evaluate VSEE on regulation of bone and lipid metabolisms. Differentiation and matrix mineralization of preosteoblast are significantly increased by VSEE (p <0.05), which attributed to stimulating calcium influx, then to activating Wnt/β-catenin signaling pathway and regulating runt-related transcription factor 2 and Osteoprotegerin. VSEE can cross Caco-2/HT-29 co-cultured monolayer via paracellular pathway and peptide transporter 1 (PepT1), and can be detected in blood and maximum concentration is 122.84 ± 3.68 mg L^-1 at 60 min. Additionally, VSEE reverses bone loss and regulate dyslipidemia through Wnt/β-catenin signaling pathway in OVX rats. Firmicutes phylum, Veillonellaceae, Prevotellaceae and six genera in VSEE group are significantly different compared with the Model group (p < 0.05).

Conclusion: VSEE promotes bone growth and inhibit abnormal lipid metabolism in an OVX model through the regulation of intestinal microbiota compositions and Wnt/β-catenin signal pathway.