Evaluating intestinal absorption of peptide Met-Lys-Pro in casein hydrolysate using Caco-2 and human iPS cell-derived small intestinal epithelial cells

• Published in: Food research international 2024-10, Vol.193, p.114831, Article 114831
• Main Authors: YAGO, Takumi, YUDA, Naoki, TANAKA, Miyuki, IWAO, Takahiro, MATSUNAGA, Tamihide
• Format: Article
• Language: English
• Subjects: Bioactive peptide; Bioavailability; Biological Availability; blood pressure; Caco-2 cell monolayer; Caco-2 Cells; Casein hydrolysate; casein hydrolysates; Caseins - metabolism; Epithelial Cells - drug effects; Epithelial Cells - metabolism; epithelium; food research; Human iPS cell-derived small intestinal epithelial cell; Humans; hypertension; intestinal absorption; Intestinal Absorption - drug effects; Intestine, Small - metabolism; intestines; peptides; Permeability; risk factors; tight junctions; Transepithelial transport
• ISSN: 0963-9969; 1873-7145; 1873-7145
• DOI: 10.1016/j.foodres.2024.114831

[Display omitted] •The intestinal absorption of casein peptide Met-Lys-Pro (MKP) was studied in vitro.•Transepithelial transport of MKP in casein hydrolysate exceeded that of MKP alone.•The peptide matrix in casein hydrolysate may suppress MKP degradation. High blood pressure is a major risk factor for cardiovascular disease. Our previous study confirmed that daily intake of casein hydrolysate that contained Met-Lys-Pro (MKP) can safely lower mildly elevated blood pressure. The present study aimed to evaluate the intestinal absorption differences between peptide MKP as a casein hydrolysate and synthetic MKP alone using Caco-2 cells and human iPS cell-derived small intestinal epithelial cells (hiSIECs). MKP was transported intact through Caco-2 cells and hiSIECs with permeability coefficient (Papp) values of 0.57 ± 0.14 × 10-7 and 1.03 ± 0.44 × 10-7 cm/s, respectively. This difference in Papp suggests differences in the tight junction strength and peptidase activity of each cell. Moreover, the transepithelial transport and residual ratio of intact MKP after adding casein hydrolysate containing MKP was significantly higher than that after adding synthetic MKP alone, suggesting that other peptides in casein hydrolysate suppressed MKP degradation and increased its　transport. These findings suggest that hiSIECs could be useful for predicting the human intestinal absorption of bioactive peptides; ingesting MKP as a casein hydrolysate may also improve MKP bioavailability.