Inhibition of angiotensin converting enzyme activity by five Senecio species.

In our continuous search of biological properties of Senecio species (Compositae), we investigated S. ambiguus subsp. ambiguus (Biv.) DC , S. gibbosus subsp. gibbosus DC , S. leucanthemifolius Poiret , S. inaequidens DC , and S. vulgaris L. for their angiotensin converting enzyme (ACE) inhibitory activity through an in vitro bioassay based on the enzymatic cleavage of the chromophore-fluorophore labelled substrate dansyltriglycine into dansylglycine, which is quantitatively measured by HPLC. Among analyzed extracts, ethyl acetate demonstrated the highest activity with IC50 values of 192.1 and 219.1 μg/mL for S. ambiguus subsp. ambiguus and S. inaequidens, respectively. Flavonoids were detected in these extracts on TLC sprayed with Natural Products reagent - polyethylene glycal reagent (NP/PEG). [ABSTRACT FROM AUTHOR]