Antioxidant Activity and Lifespan-Extending Effects of Sciadopitysin Isolated from Ginkgo biloba Leaves in Caenorhabditis elegans

In order to find lifespan extending compound from natural resources, subsequent activity-guided fractionation of Ginkgo biloba leaves (Ginkgoaceae) methanol extract was performed using Caenorhabditis elegans model system. From the most active ethyl acetate soluble fraction, sciadopitysin was isolated, and sciadopitysin showed the antioxidant activities in vitro and in vivo experiments. Sciadopitysin revealed the potent lifespan-promoting activity and it elevated the survival rate of worms against stressful environment including thermal, osmotic and oxidative conditions. As well, sciadopitysin was able to elevate antioxidant enzyme activities of nematodes, and reduced intracellular ROS accumulation of N2 worms in a dose-dependent manner. These results demonstrated that the increased stress tolerance of sciadopitysin-mediated nematode could be attributed to promoted expressions of stress resistance proteins like heat shock protein (HSP-16.2) and superoxide dismutase (SOD-3). And, intestinal lipofuscin level of nematode was decreased by sciadopitysin treatment compared with the control. Moreover it was found that there were no significant changes due to sciadopitysin in aging-related factors including food intake, reproduction, movement and growth. These results suggest that sciadopitysin exerts longevity-promoting activity without affecting above factors. Further study using knockout mutants such as daf-2 and age-1 showed that the sciadopitysin increased the activity of DAF-16 gene which can improve the lifespan of the nematodes.