Obesity and overweight have reached epidemic proportions globally with more than 1 billion adults, not only in affluent societies but also in developing countries. Moreover, obesity is considered to be one of the major risks for chronic diseases, such as hyperlipidemia, heart diseases, type 2 diabetes and disability. Other co-morbidities include gall-bladder disease, fatty liver, sleep apnea and osteoarthritis with reduced quality of life and life expectancy. Therapeutic weight loss includes a combination of diet, exercise and behaviour modification and sometimes weight loss drugs, but natural active substances offer a safe and effective solution and support to the reduction and management of body weight. Over the last years, several studies have proven the beneficial effect that flavonoids and polyphenolic compounds, widely distributed in the human diet, have on body weight-control and obesity (1,2). In vivo and in vitro studies demonstrated that flavonoids are able to affect lipid metabolism by specific molecular actions. For example, anthocyanins were shown to ameliorate adipocyte metabolism by regulation of adipocytokine gene expression (3,4). Subjects suffering from obesity showed a strong decrease in adiponection expression, one of the most important adipocytokines specifically expressed in adipocytes and involved in their dysfunctions. It was observed that in human adipocyte anthocyanin compounds can induce a normalisation of adipocytokines, such as adiponection and, consequently, could be used in the prevention and treatment of obesity and associated metabolic syndrome (3,4). Of all the plants and fruits containing flavonoid compounds, red or blood oranges (Citrus sinesis (L.) Osbeck) have been recently evaluated for their beneficial effects (5-17). In particular, several in vitro and in vivo studies have investigated the health-related properties of red orange intake (especially, Moro oranges) on weight management (18-20). Amongst blood oranges (Tarocco, Sanguinello and Moro), the Moro variety is the most brightly colored, with a deep red flesh.
The typical red coloration of the fruits is attributed to the presence of pigmented compounds called anthocyanins, not usually contained in blond sweet oranges and other citrus fruits. The blood orange is a very old orange variety, probably originated in Southeast Asia and widely spread through the Mediterranean basin during the Arab dominance in the ninth century. Nowadays, a small part of eastern Sicily is considered as a special and optimal area for the growth and production of the Moro orange, because large diurnal temperature fluctuations (hot days, cold nights) are identified as the main cause of intense red pigmentation. Thanks to the typical climatic condition of these regions, the Moro flesh ranges from orange-veined with ruby coloration, to vermilion, sometimes nearly to black. The juice obtained from Moro oranges is enriched with the combination of active substances, such as flavanoids, hydroxycinnamic acids, ascorbic acid and anthocyanins (21-23). MOROSIL® is a solid extract produced by Bionap srl containing all the active substances of Moro orange juice: anthocyanins (cyanidin-3-O-glucoside), hydroxycinnamic acids (caffeic, cumaric, ferulic, sinapic acid), flavone glycosides (narirutin, hesperidin) and ascorbic acid.
Evaluation of Moro orange juice supplementation in the weight management in humans
In a clinical trial (24), volunteers (aged 21-50 years old; body mass index between 25-35 Kg/m²) were assigned by randomization into two groups of 30 peoples. The placebo group received a dietary supplement of one tablet per day containing 400 mg of maltodextrin while the group treated with Moro juice extract received one tablet per day, between meals, containing 400 mg of Morosil. During the clinical trial, subjects were evaluated at the beginning of the study (T0), after 2 weeks (T1), 4 weeks (T2), 8 weeks (T3) and 12 weeks (T4) of treatment. At each time point, subjects were monitored for several anthropomorphic parameters such as body weight and body mass index (BMI); waist circumference and hip circumference were monitored at the beginning and the end-point of the study (24). All statistical comparisons in data were evaluated using Kruskal-Wallis test and difference between groups were tested using the Mann-Whitney U test (p 0.05 was considered significant different). Results Results obtained from this clinical study are reported in Table 1 and Fig 1. Data showed that Moro juice extract supplementation induced a significant reduction in body weight (- 3,08 ± 0.24 Kg), BMI (-1.11 ± 0.09 Kg/m²), waist (-7.08 ± 1.33 cm) and hip circumference (-5.96 ± 0.97 cm) after 12 weeks of treatment (Table 1). Statistical analysis showed that variation in treated group is significantly higher than in the placebo group (body weight= -0,41 ± 0,05 Kg; BMI= -0,15 ± 0.02 Kg/m²; waist circumference= -0.80 ± 0.15 cm; hip circumference= -0.69 ± 0.12 cm). Moreover, Figure 1 showed that a significant reduction of BMI was observed within the group treated with Moro juice extract already after 4 weeks of treatment whereas no significant variation in BMI was obtained in the placebo group at all-time points (p 0.05).
Table 1. Variations in body weight, BMI, waist and hip circumference from baseline to 12 weeks in the Placebo and in Moro juice extract supplementation group; *p 0.05 was significantly different vs placebo group.
Figure 1. Effect of Moro juice extract supplementation on BMI (Kg/m²) values in human volunteers on different time points (T0= baseline; T1= 2 weeks; T2= 4 weeks; T3= 8 weeks and T4= 12 weeks) during the treatment period; *p 0.05 significant differently vs T0 within each group
Discussion and Conclusion In the clinical trial published in Nat Prod Res (24), it was proven that Moro orange (Citrus sinensis (L.) Osbeck) extract supplementation is able to counteract fat accumulation and weight gain in the human body. Results obtained in the study showed that, after 12 weeks of treatment, Moro juice extract intake is able to induce a significant reduction in body weight, BMI, waist and hip circumference in comparison with the untreated group. Moreover, a significant reduction in body weight (BMI) was observed in volunteers treated with Moro juice extract after 4 weeks of treatment (p 0.05). Previous studies published in scientific literature have proven that Moro orange juice supplementation significantly reduced fat accumulation induced by high fat diet in mice (20). More in detail, Moro juice intake - but not blond orange (Navelina) juice - can counteract the effect of high fat diet on adipose tissue, leading to marked reduction in adipocyte cell size and lipid accumulation (a 25-50% decrease in abdominal\inguinal fat mass). Gene expression of fat tissue was analyzed and results showed that Moro juice could entirely rescue the high fatinduced transcriptional reprogramming in adipocyte cells. Moreover, Salamone et al (19) have evaluated the effect of Moro juice intake in mice fed with a high-fat diet over 12 weeks. Liver morphology, gene expression of lipid transcription factors and metabolic enzymes were investigated. The results obtained showed that Moro juice administration was able to limit body weight gain, decrease serum triglycerides and total cholesterol and improve liver steatosis in mice fed with a high-fat diet. In these studies, researchers found that administration of cyanidin- 3-glucoside did not produce the same beneficial effect on fat accumulation as Moro juice intake. All these findings suggest that Moro juice anti-obesity effect cannot be explained by anthocyanins only, but other components contained in Moro orange may act synergistically to inhibit fat accumulation (19,20). In conclusion, results recently published in scientific literature have proven that Moro juice contains active compounds able to control weight gain and fat accumulation. Consequently, the Moro juice extract MOROSIL® can be considered as a natural ingredient useful in the management of overweight and the prevention of obesity.
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