Yuxing Guo1,2, Junai Gan2, Qian Zhu1, Xiaoqun Zeng3, Yangying Sun3, Zhen Wu3, Daodong Pan1,3. 1. Department of Food Science and Technology, Ginling College, Nanjing Normal University, Nanjing, China. 2. Foods for Health Institute, Department of Food Science and Technology, University of California, Davis, CA, USA. 3. Key Laboratory of Animal Protein Deep Processing Technology of Zhejiang Province, Ningbo University, Ningbo, Zhejiang, China.
Abstract
BACKGROUND: To exert an antihypertensive effect after oral administration, angiotensin I-converting enzyme (ACE)-inhibitory peptides must remain active after intestinal transport. The purpose of this article is to elucidate the transport permeability and route of ACE-inhibitory peptide Arg-Leu-Ser-Phe-Asn-Pro (RLSFNP) across the intestinal epithelium using Caco-2 cell monolayers. RESULTS: Intact RLSFNP and RLSFNP breakdown fragments F, FNP, SFNP and RLSF were found in RLSFNP transport solution across Caco-2 cell monolayers using ultra-performance liquid chromatography-tandem mass spectrometry. RLSFNP fragments FNP, SFNP and RLSF also contributed to ACE inhibitory effects. Protease inhibitors (bacitracin and leupeptin) and absorption enhancers (sodium glycocholate hydrate, sodium deoxycholate and Na2 EDTA) improved the transport flux of RLSFNP. A transport inhibitor experiment showed that intact RLSFNP may be transported via the paracellular route. CONCLUSION: Intact RLSFNP can be transported across the Caco-2 cell monolayers via the paracellular route. Extensive hydrolysis was the chief reason for the low permeability of RLSFNP.
BACKGROUND: To exert an antihypertensive effect after oral administration, angiotensin I-converting enzyme (ACE)-inhibitory peptides must remain active after intestinal transport. The purpose of this article is to elucidate the transport permeability and route of ACE-inhibitory peptide Arg-Leu-Ser-Phe-Asn-Pro (RLSFNP) across the intestinal epithelium using Caco-2 cell monolayers. RESULTS: Intact RLSFNP and RLSFNP breakdown fragments F, FNP, SFNP and RLSF were found in RLSFNP transport solution across Caco-2 cell monolayers using ultra-performance liquid chromatography-tandem mass spectrometry. RLSFNP fragments FNP, SFNP and RLSF also contributed to ACE inhibitory effects. Protease inhibitors (bacitracin and leupeptin) and absorption enhancers (sodium glycocholate hydrate, sodium deoxycholate and Na2 EDTA) improved the transport flux of RLSFNP. A transport inhibitor experiment showed that intact RLSFNP may be transported via the paracellular route. CONCLUSION: Intact RLSFNP can be transported across the Caco-2 cell monolayers via the paracellular route. Extensive hydrolysis was the chief reason for the low permeability of RLSFNP.