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Il lavoro sperimentale è stato focalizzato sullo studio dell’effetto di differenti diete iperlipidiche, ricche in lardo e olio di pesce, sullo sviluppo dell’obesità, steatosi epatica ed insulino-resistenza. E' noto da tempo l'effetto benefico dell’olio di pesce nel ridurre le patologie cardiovascolari e le metaboliche. Proprio per questo motivo ho condotto delle analisi volte ad accertare come l’utilizzo di olio di pesce in diete iperlipidiche somministrate a ratti potesse agire sull’efficienza energetica mitocondriale e su quella corporea totale. In particolare sono stati valutati a livello corporeo totale, diversi parametri quali: composizione corporea, bilancio energetico, e livelli ematici di ormoni e metaboliti specifici. Inoltre è stata valutata anche la resistenza all’insulina e la tolleranza al glucosio e a livello mitocondriale epatico e muscolare: la velocità di ossidazione degli acidi grassi, l’efficienza mitocondriale e lo stress ossidativo. I risultati hanno mostrato come diete ad elevato contenuto di omega 3 portano ad un minore sviluppo dell’obesità, steatosi epatica ed insulino-rersistenza.

The high fat diet (HFD) rich in lard induces obesity, inflammation and oxidative stress, and the deregulation of hypothalamic nuclei plays an important role in this mechanism. One important factor involved in the food intake and inflammation is adenosine monophosphate-dependent kinase (AMPK), a serine/threonine kinase activated by phosphorylation. Omega (&)3-polyunsaturated fatty acids (PUFA) are dietary compounds known to attenuate the obesity-related diseases, although the molecular mechanisms underlying their actions in the hypothalamus are not completely understood. We hypothesized that the beneficial effects of PUFA may be mediated by AMPK in the hypothalamus. To this aim, rats were fed a control diet (CD), or isocaloric HFD containing either fish oil (FD; rich in &3-PUFA) or lard (LD) for 6 weeks, and the activation of AMPK, inflammatory state (IKKb, TNF-a) and oxidative stress were analyzed in the hypothalamus. In addition, we also studied serum lipid profile, homeostatic model assessment (HOMA) index, and pro-inflammatory parameters. Our results showed, at the hypothalamic level of LD-fed rats, an increase of AMPK activation, inflammation and oxidative stress, while no modifications were detected in FD-fed animals compared to CD. In addition body weight gain, serum lipid profile, pro-inflammatory parameters and insulin resistance were reduced in FD animals compared to LD. In conclusion, our data indicate that the substitution of saturated by unsaturated fatty acids in the diet has beneficial effects on modulation of hypothalamic inflammation and function in obesity, underlying, at hypothalamic level, the interaction among insulin and/or leptin resistance, AMPK activation and hyperphagia.