Objective: The aim of the study was to determine the content of polyphenols and flavonoids from sixteen selected medicinal plants from the spontaneous Romanian flora and fifteen tinctures obtained with propylene glycol.
Methods: The polyphenols were determined by the Folin-Ciocalteu method while the flavonoids by using a colorimetric method from the 10th edition of the Romanian Pharmacopoeia. The antioxidant activities of the most common nine medicinal plants and fifteen tinctures were determined by DPPH and ABTS methods.
Results: The results highlighted that the phenolic compounds and flavonoids have contributed to their antioxidant activities and the medicinal plants and tinctures included in the study are rich sources of natural antioxidants.
Conclusions: There are a wide variety of extraction methods for the determination of phenolics and flavonoids. The study confirms a correlation between phenolic and flavonoid contents obtained by using the DPPH and ABTS tests.