ANTIOXIDANT ACTIVITY OF TWO WILD TEUCRIUM SPECIES FROM MOROCCO

The aim of the present study was to investigate antioxidant activity, total polyphenols and total flavonoids contents of extracts from two Moroccan Teucrium species (Teucrium polium and Teucrium aurum). The Antioxidant activity was evaluated in-vitro by three assays namely, free radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP) and total antioxidant capacity. Total polyphenol content was measured using Folin-Ciocalteu assay. The aluminum chloride colorimetric test measured total flavonoids contents. The total phenols contents, flavonoids contents, and the antioxidant activity of T. polium extracts were higher than T. aurum. The phenols contents ranged from 109.28 to 20.61 mg GA E/ g dry extract. The total flavonoids varied between 102.99 and 10.33 mg RE/g dry weight. The extracts showed significant scavenging activity of DPPH, with IC₅₀ values ranging between 0.40 and 2.12 mg/ml and a good ferric reducing power, with IC₅₀ values varying from 0.15 to 4.23 mg/ml. The total antioxidant capacity assay showed that the water extract of T. polium had a highest activity with a value of 153.89 mg Vit C E/g dry weight. The ethyl acetate extract has a weak antioxidant activity in the three tests. A good correlation between antioxidant activities and contents of polyphenols and flavonoids was found. These results show that Moroccan Teucrium species, especially T. polium, is a rich source of phenols and natural antioxidant compounds, which can be used as a natural food preservative