Secoisolariciresinol Diglucoside Delays the Progression of Aging-Related Diseases and Extends the Lifespan of Caenorhabditis elegans via DAF-16 and HSF-1

Figure 5

SDG extends the lifespan of C. elegans via DAF-16. (a) The mRNA level of genes downstream of DAF-16, DAF-12, and NHR-80 in wild-type C. elegans (N2) treated with or without 500 μM of SDG. SDG significantly increased the expression of genes sod-3, fard-1, and fat-6 at mRNA level in worms (, two-tailed -test). (b) The quantification of fluorescence intensity of SOD-3::GFP in CF1553 muIs84 (sod-3::gfp) treated with or without 500 μM of SDG. Worms were observed and photographed using a fluorescent microscope (Leica DM6B) with appropriate filter sets for GFP (magnification: 100x). SDG significantly increased the expression of protein SOD-3 in C. elegans (, two-tailed -test). (c) The fat content at tail of wild-type C. elegans (N2) treated with or without 500 μM of SDG. Worms were observed and photographed using a fluorescent microscope (Leica DM6B) (magnification: 200x). SDG significantly reduced the fat content in C. elegans. (d) The progeny production of per wild-type C. elegans (N2) treated with or without 500 μM of SDG. SDG did not affect the reproductive ability of worms. (e) The mean lifespan of daf-16 mutant strain CF1038 treated with or without 500 μM of SDG at 20°C. (f) The mean lifespan of daf-12 mutant strain AA89 treated with or without 500 μM of SDG at 20°C. (g) The mean lifespan of nhr-80 mutant strain BX165 treated with or without 500 μM of SDG at 20°C. (h) The mean lifespan of glp-1 mutant strain CF1903 treated with or without 500 μM of SDG at 20°C. SDG could not extend the lifespan of daf-16, daf-12, nhr-80, and glp-1 mutant strains (, log-rank test). A statistically significant value was calculated by the -test or log-rank test; ^★; ^★★; ^★★★. The results from repeated experiments and the statistical details are summarized in supplementary Tables S5, S6, and S10-S12.

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