Transport Study of Egg-Derived Antihypertensive Peptides (LKP and IQW) Using Caco-2 and HT29 Coculture Monolayers

Qingbiao Xu, Hongbing Fan, Wenlin Yu, Hui Hong, Jianping Wu

Research output: Contribution to journalArticlepeer-review

74 Scopus citations


The objective of this study was to investigate the mechanisms of the transport of antihypertensive tripeptides LKP (Leu-Lys-Pro) and IQW (Ile-Gln-Trp) derived from egg white using a coculture system of Caco-2 and HT29 cell monolayers. The results revealed that LKP and IQW have no cytotoxicity to the cell viability after 2 h incubation, could be transported intact across coculture monolayers (apparent permeability coefficient: (18.11 ± 1.57) × 10-8 and (13.21 ± 1.12) × 10-8 cm/s, respectively), and were resistant to peptidase secreted by enterocytes. In addition, the transports were significantly inhibited by dipeptide Gly-Pro (P < 0.05), a competitive substance of peptide transporter 1 (PepT1). The transports from apical to basolateral side were significantly higher than that of the reverse direction (P < 0.05). These results suggest that PepT1 is involved in LKP and IQW transports. The transports were also significantly decreased by theaflavin-3′-O-gallate (P < 0.05), an enhancer of tight junction (TJ) and increased by cytochalasin D (P < 0.05), a disruptor of TJ but not influenced by wortamanin, a transcytosis inhibitor, suggesting that passive paracellular route via TJs is also involved in LKP and IQW transports but not transcytosis. In addition, siRNA was also used to knockdown the expression of PepT1 and significantly inhibited the transport (P < 0.05), confirming that PepT1 is involved in transport process. Therefore, both passive paracellular route via TJ and active route via PepT1 coexist in the transport of antihypertensive LKP and IQW across Caco-2/HT29 coculture monolayers.

Original languageEnglish
Pages (from-to)7406-7414
Number of pages9
JournalJournal of Agricultural and Food Chemistry
Issue number34
StatePublished - Aug 30 2017

Bibliographical note

Publisher Copyright:
© 2017 American Chemical Society.


  • Caco-2
  • IQW
  • LKP
  • antihypertensive peptide
  • transport

ASJC Scopus subject areas

  • General Chemistry
  • General Agricultural and Biological Sciences


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