In vitro antioxidant properties of Salvia verbenaca     L. hydromethanolic extract

Objective: To investigate the in vitro antioxidant activity of the hydromethanolic extract of the aerial parts (leaves and stems) of Salvia verbenaca L. towards fatty acids (linoleic and linolenic acids) and human, low density lipoproteins (LDL) peroxidation.
Materials and Methods: Lipid peroxidation was carried out in the presence of the S. verbenaca L. hydromethanolic extract (10 and 100 μg of extract/ml). CuSO₄ (10 μM) was used as the oxidation initiator. Conjugated dienes (CD) formation, oxygen consumption and thiobarbituric acid reactive substances (TBARS) formation were assessed to monitor the antioxidant properties of the plant extract. Butylated hydroxytoluene (BHT) at 50 μg/ml was used as a standard antioxidant. The quantification of total polyphenolic compounds was carried out, according to the Folin-Ciocalteu method.
Results: The hydromethanolic extract of S. verbenaca showed a significant antioxidant effect at 100 μg/mL. A strong inhibition of oxygen consumption (92%, P < 0.001) and CD formation of LDL peroxidation (92%, P < 0.001) as well as TBARS formation of linolenic acid oxidation (93%, P < 0.001) were observed. The quantitative analysis revealed that the extract used contained a high amount of phenolic compounds, suggesting a possible role of these products in the observed antioxidant properties.
Conclusion: S. verbenaca could be considered as a potential source of natural antioxidants.