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

Figure 2

SDG improves the heat stress resistance of C. elegans. (a) The survival of wild-type C. elegans (N2) treated with or without 500 μM of SDG at 35°C. SDG can significantly extend the lifespan by up to 31.6% under heat stress (, log-rank test). (b) The mRNA level of heat-shock related genes in wild-type C. elegans (N2) treated with or without 500 μM of SDG. The expression of the heat-shock related genes showed a significant difference (, two-tailed -test). (c) The pictures of green fluorescent at tail in C. elegans SJ4005 zcIs4V (hsp-4::gfp) and SJ4100 zcIs13V (hsp-6::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: 200x). The quantification of fluorescence intensity showed that the expression of HSP-4::GFP and HSP-6::GFP was significantly increased with SDG treatment (, two-tailed -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–S7.

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