BÃÂ¡rbara Graziela Postal, Samantha Manes Guesser, VirgÃÂnia Demarchi Kappel, Ana Paula Ruani, Nicolas Suarez Zamorano, Angela Machado de Campos, Flávio Henrique Reginatto, Moacir Geraldo Pizzolatti, Daniela Ota Hisayasu Suzuki and FÃÂ¡tima Regina Mena Barreto Silva
Background: Epidemiologic studies and clinical trials have suggested a correlation between dietary polyphenols and prevention of chronic diseases such as diabetes. The current study has been limited to the compounds previously studied by in vivo and in vitro experimental model concerned glucose homeostasis.
Objective: Some selected compounds as myricitrin, quercetin, catechin, naringenin, caffeic acid, rutin, fukugetin, hispidulin, kaempferitrin and chlorogenic acid were investigated in sodium-glucose co-transporter activity in rat intestine through an in situ approach, compared with phlorizin, a classical competitive inhibitor of Na+-dependent glucose transport. Methods: For the in situ studies the intestine segments were uploaded with glucose solution, phlorizin and/or compounds and after 30 min the glucose was measured into the respective intestinal segment.
Results: Among the substances assayed, myricitrin, quercetin, catechin, naringenin, caffeic acid, rutin and fukugetin significantly reduced the glucose uptake by affecting the SGLT1 transporter activity measured in the presence of phlorizin. It worthwhile mentions that myricitrin at 10mM exhibited a per se inhibitory effect around 90% higher than that observed for phlorizin. Quercetin inhibited the glucose uptake in both concentrations used and exhibited an effect on glucose absorption as good as phlorizin at 10 mM. Catechin and caffeic acid (10 mM) in the presence of phlorizin potentiated the inhibitory effect of this compound on glucose uptake. Moreover, 10 mM naringenin showed a similar inhibitory effect of phlorizin. Additionally, rutin and fukugetin (10 mM) alone or in combination with phlorizin slightly reduced the glucose absorption.
Conclusion: Based on these results, myricitrin, quercetin, catechin, naringenin, caffeic acid, rutin and fukugetin are able to regulate glucose absorption by acting in an intestinal target, SGLT1, contributing to ameliorate glucose homeostasis.