DHA-rich marine microalga Schizochytrium mangrovei possesses anti-ageing effects on Drosophila melanogaster

Docosahexaenoic acid (DHA) plays important roles in the prevention of ageing and ageing-related diseases. In this work, the anti-ageing effect of Schizochytrium mangrovei (SM), a marine microalga with high contents of DHA was investigated for the first time. In vitro results showed that SM enhanced the vitality of healthy pheochromocytoma (PC12) cells, whereas it had no protective effect under H2O2-induced oxidative stress. Meanwhile, SM exerted neuroprotective actions in vivo: the supplementation of SM significantly extended the lifespan of both wild type and SODn108 mutant flies Drosophila melanogaster, and ameliorated the age-related decline of locomotor function. This lifespan-extending activity was associated with the mRNA up-regulation of endogenous stress-defense genes such as CuZn-superoxide dismutase (SOD1) and Mn-superoxide dismutase (SOD2), as well as the down-regulation of Methuselah (MTH) gene. Therefore, it was concluded that the anti-ageing capability of DHA-rich SM was mediated through the cooperation with endogenous stress-defense system rather than the direct interaction with oxidative free radicals.