Naringenina e uptake del glucosio

[lupin III]

Biochem Biophys Res Commun. 2010 Jun 14.

Naringenin, a citrus flavonoid, increases muscle cell glucose uptake via AMPK.
Zygmunt K, Faubert B, Macneil J, Tsiani E.
(Faculty of Applied Health Sciences, Brock University, St. Catharines, ON, Canada L2S 3A1.)



Naringenin, a flavonoid found in high concentrations in grapefruit, has been reported to have antioxidant, antiatherogenic, and anticancer effects. Effects on lipid and glucose metabolism have also been reported. Naringenin is structurally similar to the polyphenol resveratrol, that has been reported to activate the SIRT1 protein deacetylase and to have antidiabetic properties. In the present study we examined the direct effects of naringenin on skeletal muscle glucose uptake and investigated the mechanism involved. Naringenin stimulated glucose uptake in L6 myotubes in a dose- and time-dependent manner. Maximum stimulation was seen with 75 muM naringenin for 2 hours (192.8+/-24%, p<0.01), a response comparable to maximum insulin response (190.1+/-13%, p<0.001). Similar to insulin, naringenin did not increase glucose uptake in myoblasts indicating that GLUT4 glucose transporters may be involved in the naringenin-stimulated glucose uptake. In addition, naringenin did not have a significant effect on basal or insulin-stimulated Akt phosphorylation while significantly increased AMPK phosphorylation/activation. Furthermore, silencing of AMPK, using siRNA approach, abolished the naringenin-stimulated glucose uptake. The SIRT1 inhibitors nicotinamide and EX527 did not have an effect on naringenin-stimulated AMPK phosphorylation and glucose uptake. Our data show that naringenin increases glucose uptake by skeletal muscle cells in an AMPK-dependent manner

[lupin III]

Spesso si e' detto che il Resveratrolo aumenti l'uptake del glucosio da parte delle cellule muscolari.
La naringenina risulterebbe utile allo stesso scopo
Da alcuni studi la naringenina esibisce altresi' una certa attivita' antiestrogenica.
Provare del pompelmo post workout potrebbe quindi rivelarsi qualcosa di utile e a costi piuttosto contenuti.

[lupin III]

Studio sulla attivita' antiestrogenica prima evidenziata.



Endocrinology Vol. 149, No. 5 2567-2575
Copyright © 2008 by The Endocrine Society


The Nutritional Flavanone Naringenin Triggers Antiestrogenic Effects by Regulating Estrogen Receptor -Palmitoylation
(Paola Galluzzo, Paolo Ascenzi, Pamela Bulzomi and Maria Marino
Department of Biology (P.G., P.A., P.B., M.M.), University "Roma Tre," I-00146 Roma, Italy; and National Institute for Infectious Diseases Istituto di Ricovero e Cura a Carattere Scientifico "Lazzaro Spallanzani" (P.A.), I-00149 Roma, Italy)

Address all correspondence and requests for reprints to: Maria Marino, Department of Biology, University "Roma Tre," Viale G. Marconi, 446, I-00146 Roma, Italy. E-mail: m.marino@uniroma3.it.


Naringenin (Nar) is a component of fruits and vegetables associated with healthful benefits, such as in osteoporosis, cancer, and cardiovascular diseases. These protective effects have been linked with Nar antiestrogenic as well as estrogenic activities. Previous studies indicate that Nar impaired estrogen receptor (ER) signaling by interfering with ER-mediated activation of ERK and phosphoinositide 3-kinase signaling pathways in the absence of effects at the transcriptional level. The present studies evaluated the hypothesis that these Nar antagonistic effects occur at the level of the plasma membrane. Our results indicate that Nar induces ER depalmitoylation faster than 17β-estradiol, which results in receptor rapid dissociation from caveolin-1. Furthermore, Nar impedes ER to bind adaptor (modulator of nongenomic actions of the ER) and signaling (c-Src) proteins involved in the activation of the mitogenic signaling cascades (i.e. ERK and phosphoinositide 3-kinase). On the other hand, Nar induces the ER-dependent, but palmitoylation-independent, activation of p38 kinase, which in turn is responsible for Nar-mediated antiproliferative effects in cancer cells. Altogether, these data highlight new ER-dependent mechanisms on the root of antiproliferative and antiestrogenic effects of Nar. Moreover, the different modulation of ER palmitoylation exerted by different ligands represents a pivotal mechanism that drives cancer cell to proliferation or apoptosis.

[lupin III]

Qui l'articolo completo:


The Nutritional Flavanone Naringenin Triggers Antiestrogenic Effects by Regulating Estrogen Receptor {alpha}-Palmitoylation -- Galluzzo et al. 149 (5): 2567 -- Endocrinology

[Guru]

E guarda un pò, anche il resveratrolo ha dimostrato di avere caratteristiche antiestrogene.

Interessante sarebbe creare un mix tutto naturale con naringina, resveratrolo, DIM e calcio glucarato.

[LiborioAsahi]

Ma se uno assume naringina, converte tutto in naringenina?!

[lupin III]

La naringina quando e' ingerita, giunge a livello intestinale e viene idrolizzata dagli enzimi alfa-ramnosidasi, eso-betaglucosidasi, endo-beta-glucosidasi e/o betaglucuronidase
Si trasforma nella sua forma agliconica (cioe' priva di zuccheri) chiamata "naringenina" e quindi viene assorbita e metabolizzata.



Arch Pharm Res. 1998 Feb;21(1):17-23.

Intestinal bacterial metabolism of flavonoids and its relation to some biological activities.
Kim DH, Jung EA, Sohng IS, Han JA, Kim TH, Han MJ.

College of Pharmacy, Kyung-Hee University, Seoul, Korea.

Abstract
Flavonoid glycosides were metabolized to phenolic acids via aglycones by human intestinal microflora producing alpha-rhamnosidase, exo-beta-glucosidase, endo-beta-glucosidase and/or beta-glucuronidase. Rutin, hesperidin, naringin and poncirin were transformed to their aglycones by the bacteria producing alpha-rhamnosidase and beta-glucosidase or endo-beta-glucosidase, and baicalin, puerarin and daidzin were transformed to their aglycones by the bacteria producing beta-glucuronidase, C-glycosidase and beta-glycosidase, respectively. Anti-platelet activity and cytotoxicity of the metabolites of flavonoid glycosides by human intestinal bacteria were more effective than those of the parental compounds. 3,4-Dihydroxyphenylacetic acid and 4-hydroxyl-phenylacetic acid were more effective than rutin and quercetin on anti-platelet aggregation activity. 2,4,6-Trihydroxybenzaldehyde, quercetin and ponciretin were more effective than rutin and ponciretin on the cytotoxicity for tumor cell lines. We insist that these flavonoid glycosides should be natural prodrugs

[Bomb Jack]

oooohh, questi sono i post che mi piacciono!
Ce ne sono altri, oltre alla naringina, che hanno la stessa funzione; inoltre la naringina è uno dei più potenti inibitori del citocromo p450 (mi pare si chiami così), aumentando potenzialmente la biodisponibilità del resveratrolo, quindi doppia sinergia!

Io consiglio un bello stack con gli altri sinergici (considerate anche la quercitina) prima di ogni buona dose di carboidrati