RESUMO
Aims: Myrtus communis L. (Myrtle) is a plant widely used in traditional medicine in the Mediterranean Sea. The aim of this study was to determine the phenolic content of Myrtus communis L. leaves and to investigate the antioxydant activity of the methanol extract and its fractions. Methodology: Myrtus communis L. leaves were extracted using organic solvents with different polarities to get the following fractions: Methanol extract (ME), chloroform extract (CE), ethyl acetate extract (EE) and aqueous extract (AqE). Total polyphenol, flavonoid and tannins contents were evaluated for all extracts. The antioxidant capacity of different extracts was assessed using nine in vitro tests. Results: The results show that ME had the highest total phenolic content (149.25±3.11 mg GAE/g of dry extract), the aqueous extract had the highest tannins content (83.35±0.36 mg TAE/ g of dry extract), whereas, EE had the highest total flavonoid content (38.4±0.9 mg QE/ g of dry extract).The EE exhibited an interesting antioxidant activity using ABTS radical scavenging assay (IC50=0.0015 mg/ml) and the DPPH test (IC50=0.004 mg/ml), while EA showed an important activity in the hydroxyl radical scavenging test (IC50=0.08 mg/ml), H2O2, (IC50=0.015 mg/ml), iron chelating (IC50=0.5 mg/ml) and reducing power (EC50=0.03 mg/ml). The greatest activity in inhibiting the oxidation of β-carotene/ linoleic acid was induced by CE and EE extracts (93.95%, and 90.29%, respectively). All extracts showed a very strong antiperoxidant effect against FTC and MDA tests. Conclusion: Myrtus communis L. leaves extracts have an important antioxidant activity which is most likely due to their polyphenolic content.