Background To the best of our knowledge, up to now, there are no reports on the antioxidant activity of phenolic compounds of Crataegus oxyacantha flowers and fruits. Such detailed information is essential to advance the existing knowledge and to promote the use of this species growing in Africa. Therefore, the objective of this investigation was to analyze the content of phenolic compounds as well as the antioxidant activities of flowers and fruits of C. oxyacantha from Bejaia (Northeastern Algeria) by different analytical methods, and to determine the relationship between them. Methods Phenolic compounds and antioxidant activity of Algerian hawthorn flowers and fruits (C. oxyacantha L.) were studied. Total phenolics, flavonoids and flavonols were determined using colorimetric methods. The phenolic profile was analyzed by high-performance liquid chromatography with diode array detection, and the in vitro antioxidant activity was measured using scavenging assay (FRAP) and Fremy's salt, using electronic paramagnetic resonance. Results Different classes of phenolic compounds were identified and quantified. Hawthorn flowers contained higher levels of hydroxycinnamic acids, vitexin derivatives and flavonols compared to fruits, while anthocyanins were present only in fruits. Significant correlations were found between phenolic content and antioxidant activity. The results also showed that although the phenolic content of the two parts was different, their antioxidant capacity was not statistically different. Conclusions The results of this study indicate that hawthorn flowers and fruits of C. oxyacantha may be considered as a natural source of bioactive compounds.
Keywords: Crataegus spp; HPLC-DAD; antioxidant activity; phenolics; vitexin, hyperoside.