Sex-Specific Lifespan Extension and Anti-Obesogenic Effects of Salicornia europaea Extract Through Tor Signaling Modulation in Drosophila

Background/Objectives: Some marine plants and algae are known to exert health benefits. However, the long-term effects and underlying mechanisms of these health benefits are still poorly understood. For this reason, we have investigated an extract from the marsh samphire Salicornia europaea for its life-prolonging potential. Methods: We investigated the effect of an aqueous extract of Salicornia europaea (SEE) on the lifespan of several wild-type strains of Drosophila. In addition, we used deficient flies to elucidate the mechanism of the life-prolonging effects. Finally, we comprehensively phenotyped the treated animals. Results: Supplementing a standard diet with SEE extended the lifespan of different Drosophila laboratory strains by up to a third (37% in w¹¹¹⁸ and 19% in yw). A total of 0.05% of SEE were ineffective, whereas 0.2% induced robust lifespan prolongation. This effect was strictly sex-specific, as the SEE application was completely ineffective in males, while prolonging life in females. We found that the body fat content of SEE-treated female flies was lower compared to controls. The extract also positively impacted the lifespan of flies fed a high-fat diet but not a high-sugar diet. SEE exhibited a lipase-inhibitory activity in vitro. Moreover, SEE counteracted aging-associated loss of intestinal barrier integrity. The sex-specific lifespan extensions induced by the SEE entirely depended on functional Tor signaling in the flies. Tissue-specific silencing of the Tor signaling pathway in different cellular compartments of the intestine reduced, but did not altogether abolish, the lifespan-prolonging effect in females. Conclusions: SEE is a promising candidate for a health-promoting intervention, as it induces lifespan-prolonging and anti-obesogenic effects in a sex-specific manner. These effects depend on functional Tor and partially on FoxO signaling. Future studies should identify the active compounds in the extract.