EPs7630® from Pelargonium sidoides increases stress resistance in Caenorhabditis elegans probably via the DAF-16/FOXO pathway

EPs7630® a water alcohol extract of the roots from Pelargonium sidoides contains several secondary metabolites including highly oxygenated coumarins, various phenolics and polyphenols. Using the DPPH assay to measure antioxidant activity a free radical scavenging activity of 14.7 ± 0.85 μg/ml (IC50) was determined. As an in vivo model Caenorhabditis elegans was applied to study the effect of EPs7630® on stress resistance. EPs7630® treatment reduces intracellular hsp-16.2::GFP expression (induced by the pro-oxidant juglone) indicating that the secondary metabolites of EPs7630® are bioavailable and exhibit antioxidant activities in vivo. Application of EPs7630® (50 μg/ml) to the transgenic mutant TJ356 induced the migration of the transcription factor DAF-16 from cytosol to the nucleus, suggesting a prominent role of DAF-16/FOXO in the daf-2 pathway for stress resistance.