Geographic origin influences the phenolic composition and antioxidant potential of wild Crataegus monogyna from Spain

Crataegus monogyna Jacq L. (Lind.) (Rosaceae) is used in folk medicine as a sedative, aerial parts being rich in polyphenols with antioxidant ability.

To study the variation in polyphenolic composition and antioxidant ability of spontaneous samples of C. monogyna in order to assess the relationship among these variables.

Aerial parts of C. monogyna were collected from nine different locations in central Spain and extracted with methanol after drying. Total polyphenols were determined by the Folin-Ciocalteu method using gallic acid (GA) as standard. Sixteen polyphenolic compounds (11 flavonoids and 5 phenolic acids) were identified and quantified by reversed-phase HPLC in one single analysis. The antioxidant ability was evaluated by the oxygen radical absorbance capacity (ORAC) and the free radical scavenging activity (DPPH) methods. Linear correlation analysis was used to explore the relationships between the studied variables.

Total polyphenol content ranged between 117.729 ± 0.011 and 204.286 ± 0.015 mg GAE/g extract, depending on the geographic origin. No relationship was found between total polyphenols and antioxidant ability by the ORAC or DPPH methods. Chromatographic analysis yielded lower amounts of polyphenols (23.3-143.26 mg/kg), as only flavonoids and phenolic acids were quantified. All the samples exhibited antioxidant activity between 1.32 ± 0.08 and 2.76 ± 0.007 μmol Trolox equivalents/mg and IC₅₀ from 0.82 ± 0.10 to 3.76 ± 0.67 μg/mL.

A statistically significant relationship between flavonoids and phenolic acids content and the antioxidant potential obtained by the ORAC method for C. monogyna samples was proven.