Effects of Tart Cherry supplementation in Diet-Induced Obesity (DIO) rats.

Excessive accumulation of adipose tissue correlates with metabolic changes that increase the risk of cardiovascular and cerebrovascular disease. Hypertension, impaired glucose tolerance, insulin resis-tance and dyslipidemia often accompanied obesity. The excess of fat storage in the abdomen is the prime cause of the metabolic abnormalities and therefore represents an important target in the treatment of obesity. Fruit and vegetable intake is inversely correlated with cardiovascular morbidity and mortality [1,2]. Furthermore, fruits and vegetables contain non-nutritive phytochemicals that may contribute to their health-promoting effects. Anthocyanins are phytochemical flavonoids principally found in red-, blue- and purple-pigmented fruits and vegetables. Several studies have suggested that anthocyanin-rich plant extracts can modify lipid metabolism in vitro and can reduce hyperlipidemia in vivo [3,4]. Tart cherries (Prunus cerasus L.) are a rich source of anthocyanins [5]. This study was designed to evaluate the effects of anthocyanin-rich tart cherries extract and seeds powder on Diet-Induced Obesity (DIO) rats. DIO rats of 7 weeks of age, expose to caloric-dense diet ad-libitum, provide a useful animal model sharing several common features with human obesity. DIO rats were studied for 17 weeks of hyper-caloric diet with the supplementation of tart cherries seeds powder (DS) and seeds powder plus tart cherries extract, containing 1mg of anthocyanins (DES). DIO rats were compared to the control rats with not fat diet (Chow).To determine the systemic effects of caloric dense expousure we examined food consumption, fat mass content and fasting glycemia, insulin levels, cholesterol and triglycerides. Ultrasonographic (US) and computed tomography (CT) evaluations were performed to detect adi-pose tissue deposition. In CT, also fat infarction of the liver was investigated. For the assessment, the difference in attenuation values between liver and spleen as well as the calculation of the spleen-to-liver attenuation ratio were taken into account. The results confirmed the development of obesity after 5 weeks of the fat diet. After 17 weeks, rats increased significantly their body weight in comparison to the control group. Glycaemia and insulin levels were higher in DIO rats, while no differences in values of total cholesterol and triglycerides were observed. Systolic blood pressure was higher in DIO rats after 17 weeks of high-fat diet com-pared to age-matched CHOW rats. The US and CT analysis indicated an increase of deposition of visceral adipose tissue and evidenced a decrease of hepatic attenuation in DIO rats. The increase of spleen-to-liver attenuation ratio in DIO rats suggests a moderate hepatic steatosis. No difference in body weight was found in DS and DES rats compared to age-matched DIO rats. Supplementation of tart cherries in DS and DES induce a decrease of the blood pressure and the glycemia. Furthermore, the serum levels of thiobarbituric reactive substances decreased without changes of the antioxidant properties. CT analysis revealed a decrease of spleen-to-liver attenuation ratio, in DES rats. The evidence of the CT was confirmed by histological analysis of liver. Sections of DIO rats present a distinctive pattern of hepatic injury characterized by steatosis with hepatocytic ballooning degeneration at the perivenular areas. The steatosis elements decrease in DS and DES rats. The preliminary findings of this study indicate that supplementation with tart cherries, although did not reduce the body weight in DIO rats, but prevent the development of related risk factors. Further studies are needed to better clarify the benefits of tart cherry supplementation on health and disease prevention. [1] P.J. Mink, C.G. Scrafford, L.M. Barraj, et al. Flavonoid intake and cardiovascular disease mor-tality: a prospective study in postmenopausal women. Am J Clin Nutr 2007, 85, 895. [2] E.J. Brunner, A. Mosdol, D.R. Witte, et al. Dietary patterns and 15-y risks of major coronary events, diabetes, and mortality. Am J Clin Nutr 2008;87:1414. [3] X. Xia, W. Ling, J. Ma, et al. An anthocyanin-rich extract from black rice enhances atheroscle-rotic plaque stabilization in apolipoprotein E-deficient mice. J Nutr 2006,136, 2220. [4] E.M. Seymour, S.K. Lewis, D. E. Urcuyo-Llanes et al. Regular Tart Cherry Intake Alters Ab-dominal Adiposity, Adipose Gene Transcription, and Inflammation in Obesity-Prone Rats Fed a High Fat Diet. J Med Food 2009, 12, 935. [5] F Blando, C Gerardi, I Nicoletti: Sour cherry (Prunus cerasus L) anthocyanins as ingredients for functional foods. J Biomed Biotechnol 2004, 2004, 253–258.