Correlations between phenolic content and antioxidant properties in twenty four plant species of traditional ethnoveterinary use in the Mediterranean area.

CONTEXT: Scientific information on antioxidant properties and phenolic content of less widely used plants can be useful. Therefore, the assessment of such properties remains an interesting and useful task, particularly for finding new sources for natural antioxidants, functional foods, and nutraceuticals. OBJECTIVE: As knowledge about antioxidant properties and phenolic content of many plant species used as traditional plant remedies is limited, we determined in vitro the total antioxidant activity and the phenolic content of several plant species traditionally used for ethnoveterinary practices. MATERIALS AND METHODS: For 24 extracts (70% acetone) from wild and cultivated plant species traditionally used for health care of animals we determined the Trolox equivalent antioxidant capacity (TEAC) by the two assays 1,1-diphenyl-2-picrylhydrazyl (DPPH) and the 2,2'-azinobis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS). The phenolic content was determined by the Folin Ciocalteu method. RESULTS: Total phenolics, calculated as gallic acid equivalent (GAE), showed variation ranging from 3.18 (Allium sativum L. (Liliaceae)) to 147.68 (Pistacia lentiscus L. (Anacardiaceae)) mgGAE/g dry weight (DW). High TEAC values corresponded to high phenolic content, while plants with low antioxidant activity exhibited low total phenolic content. The TEAC determined through each assay and total phenolic content were positively correlated, R² = 0.9152 and R² = 0.8896, respectively, for DPPH and ABTS assay. DISCUSSION AND CONCLUSION: These findings suggest that phenolic content could be used as an indicator of antioxidant properties. The results of this study encourage investigations on Mediterranean plant species as sources of antioxidants.