Compuestos polifenoles de la dieta trans-resveratrol -del mosto y el vino- y curcumina -de las especias curcuma y curry- contra la obesidad

J Pharmacol Exp Ther. 2009 Apr 9. [Epub ahead of print]Click here to read Links
The dietary polyphenols trans-resveratrol and curcumin selectively bind human CB1 cannabinoid receptors with nanomolar affinities and function as antagonists/inverse agonists.
Seely KA, Levi MS, Prather PL.

University of Arkansas for Medical Sciences.

The dietary polyphenols trans-resveratrol (found in red wine) and curcumin (found in curry powders) exert anti-inflammatory and anti-oxidant effects via poorly defined mechanisms. Interestingly, cannabinoids, derived from the marijuana plant (Cannabis sativa), produce similar protective effects via CB1 and CB2 receptors. We examined whether trans-resveratrol, curcumin and ASC-J9 (a curcumin analog) act as ligands at cannabinoid receptors. All three bind to hCB1 and mCB1 receptors with nanomolar affinities, displaying only micromolar affinities for hCB2 receptors. Characteristic of inverse agonists, the polyphenols inhibit basal G-protein activity in membranes prepared from CHO-hCB1 cells or mouse brain, that is reversed by a neutral CB1 antagonist. Furthermore, they competitively antagonize G-protein activation produced by a CB1 agonist. In intact CHO-hCB1 cells, the polyphenols act as neutral antagonists, producing no effect when tested alone, while competitively antagonizing CB1 agonist mediated inhibition of adenylyl cyclase activity. Confirming their neutral antagonist profile in cells, the polyphenols similarly attenuate stimulation of adenylyl cyclase activity produced by a CB1 inverse agonist. In mice, the polyphenols dose-dependently reverse acute hypothermia produced by a CB1 agonist. Upon repeated administration, the polyphenols also reduce body weight in mice similar to that produced by a CB1 antagonist/inverse agonist. Finally, trans-resveratrol and curcumin share common structural motifs with other known cannabinoid receptor ligands. Collectively, we suggest that trans-resveratrol and curcumin act as antagonists/inverse agonists at CB1 receptors at dietary relevant concentrations. Therefore, these polyphenols and their derivatives might be developed as novel, non-toxic CB1 therapeutics for obesity and/or drug dependence.

El humo de los cigarrillos suprime la respuesta inmune y favorece las infecciones, enfermedades pulmonares y el cáncer.

Nat Rev Immunol. 2009 Mar 30. [Epub ahead of print]Click here to read Links
How cigarette smoke skews immune responses to promote infection, lung disease and cancer.
Stämpfli MR, Anderson GP.

Martin R. Stämpfli is at the Department of Pathology and Molecular Medicine, Centre for Gene Therapeutics, and the Department of Medicine, McMaster University, Hamilton, Ontario, Canada.

A complex and multilayered immune defence system protects the host against harmful agents and maintains tissue homeostasis. Cigarette smoke ex posure markedly impacts the immune system, compromising the host's ability to mount appropriate immune and inflammatory responses and contributing to smoking-related pathologies. These adverse effects on the immune system not only occur in active smokers, but also in those exposed to smoke passively in contaminated environments, and may persist for decades after exposure has ended.