Antiaging of Cucurbitane Glycosides from Fruits of L.

Methanol extracts of L. fruits are extensively studied for their antiaging activities. A new cucurbitane-type triterpenoid (1) and nine other known compounds (2-10) were isolated, and their structures were determined according to their spectroscopic characteristics and chemical derivatization. Biological evaluation was performed on a K6001 yeast bioassay system. The results indicated that all the compounds extended the replicative lifespan of K6001 yeast significantly. Compound 9 was used to investigate the mechanism involved in the increasing of the lifespan. The results indicated that this compound significantly increases the survival rate of yeast under oxidative stress and decreases ROS level. Further study on gene expression analysis showed that compound 9 could reduce the levels of and and increase and gene expression. In addition, it could not extend the lifespan of the yeast mutants of , , , and . These results demonstrate that compound 9 exerts antiaging effects via antioxidative stress and regulation of , , , and yeast gene expression.