Prunus spinosa fresh fruit juice: antioxidant activity in cell-free and cellular systems.

The antioxidant activity was assessed of fresh juice from Prunus spinosa L. fruit (Rosaceae) growing wild in Urbino (central Italy) by using different cell-free in vitro analytical methods: 5-lipoxygenase test, 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging, and oxygen radical absorbance capacity (ORAC). Trolox was used as the reference antioxidant compound. In the 5-lipoxygenase and DPPH tests the fresh fruit juice of P. spinosa showed good antioxidant activity when compared with Trolox, while the ORAC value was 36.0 micromol eq. Trolox/g of fruit. These values are in accord with data reported in the literature for small fruits such as Vaccinium, Rubus and Ribes. The antioxidant capacity in cell-free systems of P. spinosa juice has been compared with its cytoprotective - bona fide antioxidant activity in cultured human promonocytes (U937 cells) exposed to hydrogen peroxide. The antioxidant activity of red berries has been correlated with their anthocyanin content. The results of this study indicate that the three most representative anthocyanins in P. spinosa fruit juice (cyanidin-3-rutinoside, peonidin-3-rutinoside and cyanidin-3-glucoside) are likely to play an important role in its antioxidant properties.