CITRUS LUMIA RISSO JUICE: POLYPHENOL PROFILE AND EVALUATION OF ANTIOXIDANT AND ANTI-ANGIOGENIC PROPERTIES

Citrus fruits are a rich source of bioactive compounds, which exert several health properties. We focused our attention on an ancient Mediterranean species, Citrus lumia Risso (Rutaceae), with the aim to investigate, for the first time, the polyphenol profile as well as the antioxidant and anti-angiogenic properties of its juice by several in vitro and in vivo assays. Twenty-three polyphenols were identified and quantified by RP-LC-DAD-FLD analysis. Flavonoids represent 94.22% of total polyphenols identified with flavan-3-ols as the most abundant class (79.23%) followed by flavonols (9.44%), flavanones (4.18%) and flavones (1.36%). The juice showed strong antioxidant and free radical scavenging activities, with the following order of potency expressed as half inhibitory concentration (IC50): ORAC (IC50 98.47 nL)> TEAC (IC50 209.81 nL)> DPPH (IC50 321.20 nL)> FRAP (IC50 523.43 nL). In order to evaluate the anti-angiogenic properties, two in vivo models were used, chick chorioallantoic membrane (CAM) and zebrafish embryo. Results showed that treatment with C. lumia juice determines a strong reduction of the capillary formation in the CAMs (IC50 25 μL). In addition, the juice (20 μL/embryo) was able to inhibit the endogenous alkaline phosphatase (EAP) activity released by the endothelial cells as a marker of vessel growth, without inducing any toxic or adverse effects on embryo development. These findings suggest a potential use of C. lumia Risso juice as safe natural source of antioxidants and anti-angiogenic compounds.