OxiCyan®, a phytocomplex of bilberry (Vaccinium myrtillus) and spirulina (Spirulina platensis), exerts both direct antioxidant activity and modulation of ARE/Nrf2 pathway in HepG2 cells

The antioxidant activity of plant extracts requires compelling evidence of the physiological functions of antioxidants at the cellular level. In order to assess the antioxidant power of the phytocomplex OxiCyan (R), a bilberry extract functionalized on spirulina, traditional chemical methods (DPPH and ABTS) were compared to in vitro cellular responses by using HepG2 human hepatocyte carcinoma 85011430 cell lines. OxiCyan (R) was found to act on HepG2 cells in a dual mode: with a direct effect on ROS scavenging and as a cytoprotective agent via induction of ARE/Nrf2 pathway. Direct ROS scavenging activity of OxiCyan (R) depended on the anthocyanin moiety provided by bilberry, whereas the gene activation of the ARE/Nrf2 pathway was triggered by spirulina chemical constituents. The comparative analysis of chemical and cellular assays indicated contrasting results. OxiCyan (R) showed a high antioxidant activity at the cellular level by both scavenging ROS and inducing the gene expression of natural antioxidant cell defense.