Extracts prepared from the roots of Pelargonium sidoides (DC) are commercially available
for the treatment of respiratory related conditions. Recently, a commercial radix mother
tincture of this plant was shown to have both antioxidant and anticancer effects especially
related to the G0/G1 block in the Jurkat E6.1 cell line (unpublished results). Fractions were
prepared by semi-preparative HPLC, and their antioxidant and anticancer activities were
determined. The more hydrophilic fractions isolated namely F6-F12 were all found to have
strong reducing capacities and were able to scavenge peroxyl radicals. In the human lung cell
line, NCI-H460, significant cellular antioxidant effects were observed. Anticancer activity
was evaluated in the NCI-pre-screen panel (NCI-H460, MCF-7 and SF-268) and the Jurkat
E6.1 cell line. Fractions F7, F9 and F12 were found to inhibit the cell growth of these four cell-lines (p < 0.05), especially the Jurkat E6.1 cell line with the sulforhodamine B assay.
Mass spectrometry analysis revealed that these active fractions contained several
polyphenolic compounds such as gallic acid, trihydroxycoumarin, dihydroxycoumarin
sulfates, proanthocyanidins and phenolic glycosides. A phenolic acid glycoside sulfate not
previously shown in Pelargonium sidoides extracts was also isolated. In conclusion, the
antioxidant and/or anticancer activity of the Pelargonium sidoides tincture may be attributed
to the presence of these polyphenolics.