Contribution of irisin pathway in protective effects of mandarin juice (Citrus reticulata Blanco) on metabolic syndrome in rats fed with high fat diet

The beneficial effects of Citrus fruits and their secondary metabolites on the cardiovascular system are well established. Moreover, growing evidence suggests beneficial role for prevention of obesity and related dysfunctions. Citrus reticulata Blanco (Rutaceae) is one of the most consumed Citrus fruits, but it is poorly investigated. Mandarin juice obtained from C. reticulata fruits, collected in the Horti Simplicium of Pisa Charterhouse, presents a high amount of flavanone glycosides, including hesperidin and a number of polymethoxyflavonoids, in particular nobiletin and tangeretin. On Wistar rats fed with a high fat diet for 21 days, mandarin juice significantly contained the percentage weight gain, reduced visceral adipose tissue and the inflammatory markers TNF and IL‐6. Furthermore, mandarin juice influenced irisin pathway, increasing its plasma levels. Finally, supplementation with mandarin juice contributed to improve mitochondrial membrane potential, partially compromised with high fat diet, making mitochondria less susceptible to harmful events, such as ischemia. Taken together, these results suggest that C. reticulata, through its main metabolites, is able to produce beneficial effects in metabolic syndrome and to promote browning process, through involvement of the novel interesting irisin pathway.