Assessment of antioxidant activity of natural extracts

The aim of this study was investigate and compare the antioxidant activity of extracts from Labiatae and Oleaceae cell cultures and a natural Verbenaceae extract on pig whole blood. The antioxidant activitiy was assessed using the KRL biological test. Extract obtained from Ajuga reptans (Labiatae) cell cultures and titrated at 50% of phenylpropanoids expressed as teupolioside (T), extract obtained from Siringa vulgaris (Oleaceae) cell cultures and titrated at 50% of phenylpropanoids expressed as verbascoside (V), V and T 50/50 mixture and a natural Verbenaceae extract (NE) titrated at 5% of phenylpropanoids, expressed as verbascoside, were tested for their ability to protects pig red blood cells from 2,2'azobis (2-amidinopropane) dihydrochloride (AAPH) induced hemolysis. The protective effect of the compounds was dose-dependent at concentrations of 0.1 to 1g/L. The active principle in the NE shows an antioxidant activity 2.27 times higher (P<0.01) than the cell culture extract V and 5.11 times higher (P<0.01) than the cell culture extract T. Taking into account the total phenylpropanoids content of cell cultures and natural extract, these results clearly indicate a greater antioxidant activity for the natural Verbaneceae extract.