Antioxidant, haemolytic activities and HPLC–DAD–ESI–MSn characterization of phenolic compounds from root bark of Juniperus oxycedrus subsp. oxycedrus

• The methanol extract has the highest contents in phenolic, flavonoid and tannins.
• The methanol extract contains proanthocyanidin oligomers and glycosylated flavonoids.
• The methanol extract presents interesting antioxidant activity.
• Juniperus oxycedrus root bark extracts display a low haemolytic activity.

This study investigates the phenolic compound content antioxidant and haemolytic activities in four extracts (methanol, water, hexane and dichloromethane) of Juniperus oxycedrus subsp. oxycedrus root bark. The methanol extract was the most concentrated in total phenolics (76.1 ± 2.8 mg GAE/g DW), flavonoids (39 ± 2.5 mg CE/g DW) and tannins (31.3 ± 2.1 mg CE/g DW). HPLC–MSn analysis of the methanol extract led to the identification of proanthocyanidin oligomers, quercetin hexose, quercitrin, and isorhamnetin hexose. The highest antioxidant activities were found in the methanol extract which exhibited the lowest IC50 in all the antioxidant assays i.e. DPPH, ABTS, oxygen singlet, hydroxyl radical and superoxide anion scavenging assays, inhibition of the β-carotene bleaching and lowest EC50 in iron reducing assays. Incubation of the four extracts (20 mg/ml) with human erythrocytes for one hour led to haemolytic activities between 2.05% and 4.37%. The present findings suggest than the root bark could be used as food ingredient.