Effects of Prunus cerasus L. seeds and juice on liver steatosis in an animal model of diet-induced obesity.

Visceral adipose tissue (VAT) has emerged as a major player in driving obesity-related inflammatory response [1]. In obesity, chronic infiltration of macrophages in adipose tissue mediates local and systemic inflammation [2]. In overweight individuals, a dangerous feedback loop may develop: increased VAT leads to chronic inflammation, which, in turn, leads to insulin resistance promoting VAT storage and enhances susceptibility to disease [3]. VAT mass is also a major determinant of endothelial dysfunction, liver steatosis, plasma adiponectin level, atherosclerosis and metabolic syndrome [4]. The tart cherries (Prunus Cerasus L.) juices were found to contain expected abundances of anthocyanins and flavonoids [5]. These components can modify lipid metabolism in vitro, reduce hyperlipidemia in vivo and possess high antioxidant activity [6]. Tart cherry seed contains unsaturated fatty acids, oleic acids, various bioactive structures such as polyphenols, flavonoids, vegetable acids, and pro- and anthocyanidins, which could have a useful therapeutic effect in the prevention of various vascular diseases [7]. The purpose of this study was to investigate the effects of tart cherries seeds and juice on adipogenesis and inflammation in VAT of rats fed with a high-fat diet. Diet-induced obesity (DIO) rats were used, because share many characteristics with human obesity [8]. For 17 weeks, rats were fed with a hypercaloric diet supplemented with tart cherries seeds powder (DS) and seeds powder plus tart cherries juice (DJS). DIO rats were compared to the control rats fed with a standard diet (CHOW). In VAT, the expression of PPARγ, SREBP-1c, p53, NF-κB, TNF-, CcL2, CD-68 were measured by qRT-PCR, western blot, and immunohistochemistry techniques. The DIO rats demonstrated significant increases in body weight compared to the CHOW rats. No difference in VAT weight was found in DS and DJS rats compared to age-matched DIO rats. However, tart cherries supplementation seems to modulate VAT depot by downregulating several adipocyte-specific transcription factors, including SREBP-1c and PPARγ, which play a critical role in the activation of adipogenesis. Moreover, the increased levels of inflammatory markers, induced by the diet in DIO rats, was modulated by tart cherries supplementation. These results suggest that tart cherries enriched-diet, although did not modify the accumulation of VAT, decreases inflammation and adipogenesis. Therefore, the addition of tart cherry to the diet and lifestyle interventions may modify adipose tissue cells metabolism, induce preferential mobilization of visceral fat and reduce the obesity-related multiple organ injuries.