Different HPLC-separated fractions of E. purpurea root ethanol extract produce different effects on transient increase in the concentration of cytosolic Ca
2+ in HEK293 cells. Three example traces are shown. (Statistical analysis of data from all fractions is presented in Figure 3.) Left: Average traces from the treatment of at least 20 cells per experiment, representative of three independent experiments. Fractions were applied according to their effects in the initial trials. For each of the bioactive fractions, the increase in cytosolic Ca2+ concentration was statistically significant as compared to 1% DMSO control treatment (p < 0.001). Right: GC-MS chromatograms of metabolites in these three fractions; chemically identifiable metabolites are labelled. Inactive fractions (e.g., fraction #67), were also applied after active fractions to confirm that the particular HEK293 culture used was indeed responsive to Echinacea extracts. The exposure time to each fraction is 2 min.