Antioxidant activity of Ziziphora tenuoir methanolic extracts and comparison of the essential oil in two stages of growth

Flavonoids, anthocyanins, antioxidant capability, total phenolic, ascorbic acid contents, and essential oils compounds of Ziziphora tenuoir (Lamiaceae) for polar and non-polar subfraction in different stages of growth (pre-flowering and flowering) were evaluated in this work. Antioxidant activities of the samples were determined by three testing systems namely DPPH, β-carotene/linoleic acid, and reducing power assay. In the DPPH system, the highest radical scavenging activity was seen by the nonpolar subfraction of the methanol extract in the flowering stage (IC50 43.17 ± 3.68 μg·mL−1). Large differences in the amount of phenolic compounds, antioxidant activity, anthocyanins, and flavonoids of Z. tenuoir in two stages of growth were detected. The chemical composition of the hydrodistilled essential oil of the aerial parts of Z. tenuoir was analyzed by GC/MS and compared in the two stages of growth. The main constituents of the 28 identified compounds in the oil were found to be pulegone (67.34% vs 59.61%), β-humulene (3.24% vs 3.25%), and limonene (5.06% vs 2.57%) at the flowering and pre-flowering stages, respectively