Antioxidant Activity in Vitro of Antarctic Krill Phospholipids and Its Anti-aging Effect on Caenorhabditis elegans

In order to explore the antioxidant and anti-aging effects and underlying mechanism of Antarctic krill phospholipids, the antioxidant capacity in vitro of krill phospholipids was evaluated by radical scavenging capacities against 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation, and ferric ion reducing power. Meanwhile, the effect of krill phospholipids at different concentrations on the life span, swallowing frequency, head swinging frequency, acute oxidative stress resistance, heat stress resistance, reactive oxygen species (ROS) levels, antioxidant capacity and aging-related gene expression in the model organism Caenorhabditis elegans was studied. The results showed that krill phospholipids had good antioxidant capacity in vitro, which was superior to that of soybean phospholipids. Compared with the control group, krill phospholipids at all concentrations tested prolonged the life span of C. elegans, improved the swallowing frequency and mobility, and enhanced the resistance to stress. Moreover, krill phospholipids at the medium and high concentrations significantly increased the activities of superoxide dismutase and catalase (P < 0.01) and the content of glutathione (P < 0.05), and significantly reduced the content of malondialdehyde (MDA) and ROS levels (P < 0.01). In addition, krill phospholipids prolonged the life span of C. elegans by activating the transcription factors DAF-16, SKN-1 and HSF-1 and up-regulating the expression of antioxidant and detoxification genes. To sum up, krill phospholipids have good antioxidant capacity both in vivo and in vitro and delay the aging of C. elegans, thus being a potential functional food ingredient.