Background

Curcumin, an extract from the rhizome of the plant Curcuma longa (turmeric), has been widely used as a spice and herbal medicine in Asia. It has been suggested to have many biological activities, such as antioxidative, antiinflammatory, anticancer, chemopreventive, and antineurodegenerative properties. We evaluated the impact of curcumin on life span, fecundity, feeding rate, oxidative stress, locomotion, and gene expression in two different wild-type Drosophila melanogaster strains, Canton-S and Ives, under two different experimental conditions.

Results

We report that curcumin extended the life span of two different strains of D. melanogaster, an effect that was accompanied by protection against oxidative stress, improvement in locomotion, and chemopreventive effects. Life span extension was gender and genotype specific. Curcumin also modulated the expression of several aging-related genes, including mth, thor, InR, and JNK.

Conclusions

The observed positive effects of curcumin on life span and health span in two different D. melanogaster strains demonstrate a potential applicability of curcumin treatment in mammals. The ability of curcumin to mitigate the expression levels of age-associated genes in young flies suggests that the action of curcumin on these genes is a cause, rather than an effect, of its life span-extending effects.

A fundamental question in biology is how vertebrates evolved and differ from invertebrates, and little is known about differences in the regulation of translation in the two systems. Herein, we identify a threonyl-tRNA synthetase (TRS)-mediated translation initiation machinery that specifically interacts with eIF4E homologous protein, and forms machinery that is structurally analogous to the eIF4F-mediated translation initiation machinery via the recruitment of other translation initiation components. Biochemical and RNA immunoprecipitation analyses coupled to sequencing suggest that this machinery emerged as a gain-of-function event in the vertebrate lineage, and it positively regulates the translation of mRNAs required for vertebrate development. Collectively, our findings demonstrate that TRS evolved to regulate vertebrate translation initiation via its dual role as a scaffold for the assembly of initiation components and as a selector of target mRNAs. This work highlights the functional significance of aminoacyl-tRNA synthetases in the emergence and control of higher order organisms.