Antioxidant Activity of Iranian Echium amoenum Fisch & C.A. Mey Flower Decoction in Humans: A cross-sectional Before/After Clinical Trial.

Medicinal plants are recognized as sources of natural antioxidants that can protect from biological system oxidative stress. The present cross-sectional before/after clinical trial was carried out to investigate the antioxidant properties of the decoction of the flowers of Echium amoenum Fisch & C.A. Mey in humans. A group of 38 healthy subjects was invited to use the E. amoenum (7 mg kg(-1)) twice daily for 14 days. Blood samples before and after entering the study were measured for lipid peroxidation level (LPO), total antioxidant capacity (TAC) and total thiol (SH) molecules. A significant reduction of blood LPO (24.65 +/- 11.3 versus 19.05 +/- 9.7, P = 0.029) was observed after 14 days of E. amoenum consumption. Blood TAC (1.46 +/- 0.51 versus 1.70 +/- 0.36, P = 0.018) and total thiol molecules (0.49 +/- 0.11 versus 0.56 +/- 0.12, P = 0.001) increased after 14 days of E. amoenum consumption. In conclusion, this antioxidative stress potential of E. amoenum may be due to its bioactive antioxidant components, especially rosmarinic acid and flavonoids. In recent years the importance of oxidative stress in the pathophysiology of many human disorders has been confirmed, thus use of this plant as a dietary supplement is highly recommended.