The effects of plant extracts on hPON1 activity have been examined extensively, and it has been suggested that antioxidants may enhance serum PON1 activity. In this work, we studied the effects of the flower and leaf extracts of Ferulago macrocarpa and Ferulago angulata on the paraoxonase activity of serum hPON1. The functional groups of the constituents in Ferulago macrocarpa flower and leaf extract were analyzed using the FTIR spectroscopy and their effect on the Paraoxonase-1 activity was determined by measuring the rate of paraoxon hydrolysis substrate conversion to p-nitrophenol, which was monitored at 405 nm. Our findings indicated that the extracts increased serum hPON1 activity at specific concentrations, depending on incubation time. The highest and lowest enzymatic activities were recorded after 60 minutes of incubation with 500 μg/mL of the flower extract and at the presence of 100 μg/mL of the flower extract, after 300 minutes of incubation, respectively. For Ferulago angulata
F. macrocarpa extract reduced free radicals by 47% in DPPH assay. FTIR revealed that the main compounds in flower and leaf extracts are phenolic compounds. We concluded that the activatory effects of the extracts on hPON1 paraoxonase activity was probably due to the presence of phenolic compounds, which their antioxidant activities have been cleared in some studies conducted on other extracts and essences from other plants.