Effect of Solvent Extraction on Phenol, Flavonoids and Antioxidant Activity of some Iranian Native Herbs

Introduction: Nowadays, different solvents are used to extract plant antioxidants. Each solvent has a special ability to extract antioxidants materials. Accordingly, in this research, some medicinal herbs were collected from different vegetation zones of Iran and evaluated based on the majority of useful solvents. The best solvent for the extraction of antioxidants can be identified and used to determine the best herbal medicine.   Materials & Methods: In order to investigate the type of solvent extraction on the amount of antioxidant material of some indigenous medicinal plants of different regions of Iran such as Mentha asiatica, Ziziphora persica, Otostegia persica, Crocus sativus, Achillea millefolium, Mentha longifolia, Hyssopus officinalis, Thymus vulgaris, Fumaria officinalis and Teucrium polium, were done the experiment in The factorial based on a completely randomized design with three replications. DPPH was used to measure antioxidant activity.   Findings: Results showed that the extract (hydro, hydroalcoholic, acetone and methanolic) and the interaction of extract and plant on antioxidant properties had a different effect on phenol and flavonoid content (P<0.05). The highest flavonoids in the aqueous extract (87.6 mg/gDW), hydroalcoholic (147.48 mg/gDW), methanolic (277.48 mg/gDW) and acetone (171.98 mg/gDW) and also, the highest amount of phenol in aqueous extracts (15.33 mg / gDW), hydroalcoholic (20.18 mg/gDW), methanolic (51.47 mg/gDW) and acetone (31.59 mg/gDW) were found the Achillea millefolium from Ilam. The highest antioxidant activity based on DPPH test in aqueous extract (8.29% at a concentration of 16 μg/ml) belonged to the Achillea millefolium from Ilam, In hydroalcoholic extract (34.49% at a concentration of 64 μg/ml) was belonged to Mentha asiatica in Kashmar and then Achillea millefolium in Ilam, In the extract of Estonia (62.009% at a concentration of 64 μg/ml) was belonged to Mentha asiatica of Kashmar and then Teucrium polium of Kashmar and Achillea millefolium of Ilam, Finally, in the methanolic extract (95.633% at a concentration of 16 μg/ml), was belonged to the Achillea millefolium of Ilam.   Discussion &Conclusions: In general, the results of this study showed that the most important solvent for the extraction of phenolic substances and the evaluation of oxidative properties was a methanol solution and the most effective plant with more substances and antioxidant activities were Achillea millefolium from Ilam region.