Epigallocatechin-3-gallate Inhibits Lactase but Is Alleviated by Salivary Proline-Rich Proteins

Naz, Shahina; Siddiqi, Rahmanullah; Dew, Tristan P.; Williamson, Gary

Abstract

Lactase phlorizin hydrolase is a small intestinal brush border enzyme that catalyzes the hydrolysis of the milk sugar, lactose, and also many flavonoid glucosides. We demonstrate that epigallocatechin-3-gallate (EGCG), the principal flavonoid from green tea, inhibits in vitro hydrolysis of lactose by intestinal lactase. We then tested the hypothesis that salivary proline-rich proteins (PRPs) could modulate this inhibition and stabilize EGCG. Inhibition by EGCG of digestive enzymes (α-amylase > chymotrypsin > trypsin > lactase ≫ pepsin) was alleviated ∼2−6-fold by PRPs. Furthermore, PRPs appeared stable to proteolysis and also stabilized EGCG under digestive conditions in vitro. This is the first report on EGCG inhibition of lactase, and it quantifies the protective role of PRPs against EGCG inhibition of digestive enzymes.

Citation

Naz, S., Siddiqi, R., Dew, T. P., & Williamson, G. (2011). Epigallocatechin-3-gallate Inhibits Lactase but Is Alleviated by Salivary Proline-Rich Proteins. Journal of Agricultural and Food Chemistry, 59(6), 2734-2738. https://doi.org/10.1021/jf103072z

• Journal Article Type: Article
• Acceptance Date: Feb 4, 2011
• Online Publication Date: Feb 24, 2011
• Publication Date: Mar 23, 2011
• Deposit Date: Aug 3, 2020
• Journal: Journal of Agricultural and Food Chemistry
• Print ISSN: 0021-8561
• Electronic ISSN: 1520-5118
• Publisher: American Chemical Society
• Peer Reviewed: Peer Reviewed
• Volume: 59
• Issue: 6
• Pages: 2734-2738
• DOI: https://doi.org/10.1021/jf103072z
• Keywords: General Chemistry; General Agricultural and Biological Sciences
• Public URL: https://nottingham-repository.worktribe.com/output/4678259
• Publisher URL: https://pubs.acs.org/doi/10.1021/jf103072z