Antioxidant, cardiomyocyte anti-ageing properties and phytochemical profile of Citrus bergamia juices

The increase of free radicals is involved in the pathogenesis of many age-related diseases and in particular in cardiovascular diseases (Kovacic et al. 2011). The intake of food containing phytochemicals such as polyphenols and flavonoids reduces the risk of age-related cardiovascular diseases (Holt et al. 2012). In this contest, from Mediterranean area, Citrus bergamia Risso et Poiteau (Rutaceae), bergamot, is a natural source of flavonoids, both flavanones and flavones, which exhibited antioxidant (Ferlazzo et al., 2015) and anti-inflammatory activities (Risitano et al., 2014). So, the aim of our research was to investigate the potential anti-ageing effects of fresh bergamot juice of three different cultivars. Initially, the juices obtained from “Fantastico”, “Femminello”, and “Castagnaro” cultivars of C. bergamia fruits were investigated for antioxidant activity by four different and complementary assays (Armentano et al. 2015). Three of them (O2•-, •NO and FRAP) have not been previously reported for measuring the activity of tested samples. Moreover, the Relative Antioxidant Capacity Index (RACI) was calculated to compare antioxidant capacities of all samples tested by different assays. The results showed that “Fantastico” cultivar juice possesses the strongest antioxidant activity with highest RACI (0.55), followed by “Castagnaro” cultivar (-0.09). Successively, myocardial H9c2 cells were treated with the lyophilized bergamot juice of “Fantastico” cultivar (Dong et al. 2013), which showed the highest antioxidant potential. The results demonstrated that bergamot juice from “Fantastico” cultivar did not exert any cytotoxic effect on H9c2 cells and counteracts chemical-induced senescence in myocardial H9c2 cells. Moreover, the juice flavonoid profiles of the three cultivars were assessed by high performance liquid chromatography-photodiode array-electrospray-mass spectrometry (HPLC-PDA-ESI-MS/MS). Flavonoids, both flavone, flavanone glycosides and two limonoid glycosides were detected. The overall results suggested that bergamot juice of “Fantastico” cultivar possesses beneficial health effects that make it useful as a source of health promoting constituents with antioxidant and anti-senescence properties.