Superior Intracellular Antioxidant Activity of an Astaxanthin-Containing Corynebacterial Extract

Astaxanthin can be derived from different sources such as petrochemical synthesis, natural sourcing from green algae or by microbial fermentation. As one of the strongest antioxidants known by nature, astaxanthin is rising attention as an active ingredient in cosmetical products to support the skin against oxidative stress. In contrast to widely performed chemical antioxidant activity assays, this study focuses on the comparison of synthetic, algal and corynebacterial astaxanthin in a physiological relevant test setting: the intracellular antioxidant activity in cultured human skin cells, keratinocytes. The astaxanthin-rich corynebacterial oleoresin demonstrated to be the superior antioxidant in that assay with a EC50 of 2.7 µM whereas the synthetic and algal-based variants showed no significant effect. In terms of an application of such raw materials, it is therefore tempting to speculate that astaxanthin-containing corynebacterial oleoresins could serve as a natural and superior active ingredient for skin health applications in the future.