Antioxidant activity, total phenolic content and flavonoid concentrations of different plant parts of Teucrium polium L. subsp. polium

Total phenolic content, concentration of flavonoids and in vitro antioxidant activity of twenty different extracts from the whole plant and plant parts (leaves, flowers and stems) of Teucrium polium were determined. The total phenolic contents ranged between 14.57 to 157.84 mg of GaA/g of extract. The concentrations of flavonoids varied from 6.48 to 139.87 mg of Ru/g of extract. Antioxidant activity was determined in vitro using DPPH reagent and expressed as concentration of each extract required to inhibit radical by 50% (IC50) values that ranged from 26.30 to 2190.75 µg/ml. The methanolic leaves extract contain the greatest concentration of phenolic compounds (157.84 mg of GaA/g) and showed strong antioxidant activity (IC50 = 26.30 µg/ml). Ginkgo and Green tea extracts were analyzed for comparison, and the results indicated that some extracts of T. polium were equal in activity with Ginkgo or Green tea and some appeared to have greater activity. The obtained results suggest strong antioxidant activity and large contribution of separate analysis for the maximum exploitation of active phenolic compounds from T. polium. Based on this information, plant parts of this plant are natural sources of antioxidant substances of high importance.