Antioxidant effect and study of bioactive components of Valeriana sisymbriifolia and Nardostachys jatamansii in comparison to Valeriana officinalis.

The roots of Nardostachys jatamansi have been used as a substitute for valerian in Iranian traditions. Moreover, six species from Valeriana genus such as V. sisymbriifolia grow in Iran which has not been studied yet. We aimed to study of antioxidant effect of Valeriana officinalis, Nardostachys jatamansi and Valeriana sisymbriifolia and comparing their content of valerenic acid and valepotriate. Antioxidant effect was evaluated using diphenylpicrylhydrazyl (DPPH) inhibition and beta carotene-bleaching assays. Identification of valepotriates was achieved using chemical and TLC method. Qualitative and quantitative analysis of valerenic acid was performed using TLC and spectrophotometry methods. Among the tested samples, V. Officinalis showed the highest DPPH inhibition effect with IC(50) value of 38mg/mL. All of the tested plants potentially inhibited beta-carotene oxidation. The calibration curve of authentic valerenic acid was linear in the range of 2-51 mg L(-1). The most and least amount of valepotraites was detectable in V. officinalis and V. sisymbriifolia respectively. Total valerenic acid in different plant species ranged from 0.02% in V. sisymbriifolia to 0.07% (w/w) in V. Officinalis. Our results indicated that all three tested plants contain different amount of valepotriates and valerenic acid. The highest percentage of valepotriates and valerenic acid was detectable in V. officinalis. Overall can conclude that N. jatamansii and V. sisymbriifolia would be a good candidate for substitutation of V. officinalis with noticeable antioxidant effect.