The Effect Of Echinacoside On Caenorhabditis Elegans Lifespan And Its Molecular Mechanism

Echinacoside(ECH) is a natural phenylethanoid glycosides(PhGs) found in various species such as the Echinacea angustifolia and the popular traditional Chinese herbal medicine Cistanche tubulosa. It has been reported that ECH possess an array of important pharmacological properties such as antioxidative, antiinflammatory, neuroprotective, hepatoprotective and nitric oxide radical-scavenging activities. However, whether ECH can affect longevity in vivo and what are the underlying molecular mechanisms associated with its anti-aging property have not been rigorously tested.Objective: We aim here to evaluate the anti-aging effect of echinacoside in C.elegans and explore the underlying mechanisms.Methods: 1. Life span assay: We treated wild-type N2 worms with ECH at 50, 150, 300, and 600 ?M to evaluate the effect of ECH on the lifespan and to determine the effective dosages of ECH. 2. Stress assays: ECH treated and untreated worms were subjected to paraquat oxidative stress and 37? heat stress. 3. Reproduction assay:We tested the period of reproduction and the number of reproductive output in ECH-treated and untreated worms. 4. Pharyngeal pumping assay: We estimated the food intake by counting pharyngeal pumping in 300 ?M ECH treated and untreated worms. 5. daf-16(mg Df50) mutant life span assay:We tested the lifespan of 300 ?M ECH treated and untreated daf-16(mgDf50) mutant worms. 6. DAF-16 translocation assay:The mutant TJ356(DAF-16::GFP) worms were treated with 300 ?M ECH under normal culture conditions and then observed subcellular DAF-16 localisation. 7. Quantitative real-time PCR: The mRNA levels of sod-3, hsp-16.2 and ctl-1 in N2 worms treated with and without 300 ?M ECH were quantified using quantitative real-time PCR.Results: ECH is able to significantly prolong the lifespan of wild-type C. elegans, and 300 ?M ECH is best dosage. Our further studies indicate that the beneficial effects of ECH could be observed not only under the normal conditions but also under oxidative and thermal stresses. We also found that ECH-mediated lifespan extension is not associated with any significant change in the reproductive capacity or feeding behavior in C. elegans. Our mechanistic studies suggest that ECH supplementation modulates the nuclear localization and transcriptional activities of DAF-16 and thus fine tunes the expression of DAF-16 target genes to promote longevity and increase stress response in C. elegans.Conclusion: This work reveals the longevity effect of ECH and elucidates the underpinning mechanisms. Given that daf-16 is highly conserved from C. elegans to mammals, our findings have important implications in utilizing ECH to improve the outcome of disease associated with aging in humans.