Pterostilbene effects on longevity and oxidative stress in Drosophila melanogaster

Pterostilbene (PTS) could be considered as a dimethoxylated resveratrol (RSV) derivative. Both of these stilbenoids represent a group of natural phenolic compounds, known in traditional Chinese and Japanese medicine for their protective roles and found in different types of plants and fruits such as blueberries and grape, respectively. Recent findings indicated that PTS is a more potent modulator of cognition and cellular stress than RSV [1]. The present study was carried out to investigate the anti-aging and antioxidant effect of a lifelong dietary supplementation of PTS in Drosophila melanogaster (fruit flies). We also explored the gender differences in response to PTS supplementation. Dietary PTS supplementation showed a significant effect on improving the mean life span of both male and female fruit flies. To study the antioxidant effect of PTS, flies were exposed to ethanol in order to induce oxidative stress. PTS did not significantly counteract oxidative stress in female flies meanwhile PTS significantly reduced male fly mortality. Real time PCR analysis were carried out after 2 weeks (T1) and 2 months (T2) PTS supplementation to investigate the potential modulation of the expression of proteins involved in senescence, longevity and oxidative stress. PTS treatment significantly increased NOTCH and SIRT 1 expression in female flies at T1 and T2; whereas, only at T2 in male flies. FOXO was up-regulated at T1 in females meanwhile was up-regulated at T2 in males. HO-1 and TRX were not modulated by PTS in females. On the contrary, TRX and HO-1 were up-regulated at T2 in males, and TRX also at T1 in agreement with the oxidative stress results that showed a significant reduction of mortality in males. In conclusion, our data confirm a role of PTS in increasing mean life span of both male and female flies but indicated a different effect in the two genders in particular in respect to oxidative stress