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

TL;DR

A marsh plant extract extends female fruit fly lifespan by a third and reduces body fat, likely through Tor signaling.

Contribution

Discovery of a sex-specific lifespan extension and anti-obesity effect of Salicornia europaea extract in Drosophila.

Findings

SEE extended female Drosophila lifespan by up to 37% but had no effect on males.

SEE reduced body fat and improved intestinal barrier integrity in treated females.

Lifespan extension by SEE depends on Tor signaling and partially on FoxO signaling.

Abstract

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.

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