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In Vitro and In Vivo Inhibition of Intestinal Glucose Transport by Guava ( Psidium Guajava ) Extracts
Author(s) -
Müller Ulrike,
Stübl Flora,
Schwarzinger Bettina,
Sandner Georg,
Iken Marcus,
Himmelsbach Markus,
Schwarzinger Clemens,
Ollinger Nicole,
Stadlbauer Verena,
Höglinger Otmar,
Kühne Tobias,
Lanzerstorfer Peter,
Weghuber Julian
Publication year - 2018
Publication title -
molecular nutrition and food research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.495
H-Index - 131
eISSN - 1613-4133
pISSN - 1613-4125
DOI - 10.1002/mnfr.201701012
Subject(s) - psidium , glut2 , glucose transporter , in vivo , chemistry , glucose uptake , in vitro , pharmacology , biochemistry , ic50 , food science , biology , botany , microbiology and biotechnology , insulin
Scope Known pharmacological activities of guava ( Psidium guajava ) include modulation of blood glucose levels. However, mechanistic details remain unclear in many cases. Methods and results This study investigated the effects of different guava leaf and fruit extracts on intestinal glucose transport in vitro and on postprandial glucose levels in vivo. Substantial dose‐ and time‐dependent glucose transport inhibition (up to 80%) was observed for both guava fruit and leaf extracts, at conceivable physiological concentrations in Caco‐2 cells. Using sodium‐containing (both glucose transporters, sodium‐dependent glucose transporter 1 [SGLT1] and glucose transporter 2 [GLUT2], are active) and sodium‐free (only GLUT2 is active) conditions, we show that inhibition of GLUT2 was greater than that of SGLT1. Inhibitory properties of guava extracts also remained stable after digestive juice treatment, indicating a good chemical stability of the active substances. Furthermore, we could unequivocally show that guava extracts significantly reduced blood glucose levels (≈fourfold reduction) in a time‐dependent manner in vivo (C57BL/6N mice). Extracts were characterized with respect to their main putative bioactive compounds (polyphenols) using HPLC and LC‐MS. Conclusion The data demonstrated that guava leaf and fruit extracts can potentially contribute to the regulation of blood glucose levels.