The Antioxidant Capacities and Total Phenolic Contents of Some Medicinal Plants in Iran

Free radicals are highly reactive molecules may cause great damage to cell membranes and DNA and Result in inducing oxidation DNA mutations leading to cancer, degenerative, and other diseases. Plant antioxidant derived may be preventive of free radical damages. The Stems and flower sample of plants air-dried, finely ground and were extracted by ethanol: water (70:30) for 48 h. Extracts were filtered and dried under vacuum. The antioxidant activity of five ethanolic extract of medicinal plants (Descurainia Sophia, Plantago major, Trachyspermum copticum L, Coriandrum sativum and Trigonella foenum-graecum) from Iran were analysed by five different methods [1,1- diphenyl-2-picrylhydrazyl (DPPH) radical, 2,2,azinobis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) radical cation, Ferric-reducing antioxidant power assay (FRAP), phosphomolybdenum (PMB) and reducing power (RP)]. In addition, for determination of antioxidant components total phenolic content was also analyzed. The total phenolic content of medicinal plant ranges from 74 to 154.3 mg Gallic acid/g extract as measured by the Folin–Ciocalteau method. Values of DPPH varied from 15.5 to 19.6 μmol trolex/g. FRAP ranged from 124.2 to 753 μmol of Fe(II)/g extract. Antioxidant activity of the Plantago major was always higher compared to the other plants extracts values of total phenols content and antioxidant capacity by DPPH, ABTS, FRAP, (154.33 mg GAE/g, 1856 μmol trolox, 750 μmol trolox and 1169 μmol of Fe(II)/g, extract respectively). The range of total antioxidant activity by phosphomolybdenum method was 513.3 to 870 μmol trolox/g. The reducing ability of the tested extracts was between 0.31-1.26. Plantago majorwas also highest activity in both tests. This study clearly demonstrated that Plantago major crude extract exhibit significant antioxidant activity.