Antioxidant capacity and total phenol and flavonoid contents of Teucrium polium L. grown in Algeria

BACKGROUND: Teucrium polium L. aerial parts are traditionally used in Algerian folk medicine due to its therapeutic properties. OBJECTIVE: The present study was designed to evaluate the effect of different extracting solvents (methanol, ethanol, ethyl acetate, chloroform, hexane and water) on antioxidant capacity and total phenol and flavonoid contents of Algerian Teucrium polium aerial parts. METHODS: The antioxidant capacity of Teucrium polium extracts was assessed by DPPH (2, 2-diphenyl-1-picrylhydrazyl) and ABTS (2, 2’-azino-bis 3-ethylbenzthiazoline-6-sulfonic acid) free radicals scavenging and reducing power assays. For each extract, the total phenol and flavonoid contents were investigated by the Folin-Ciocalteu and aluminium trichloride methods, respectively. RESULTS: All the tested extracts showed an appreciable total phenolic and total flavonoid contents and strong antioxidant capacity. Among the different extracts, the methanolic extract was found to be containing the highest amount of total phenols (206.95±1.82 mg of gallic acid equivalent per gram of extract) and flavonoids (42.16±0.61 mg of quercetin equivalent per gram of extract). The same extract also exhibited a much better reducing power and scavenging capacity against DPPH (IC50 = 6.77±0.15 mg/l) and ABTS (IC50 = 2.79±0.07 mg/l). CONCLUSION: These findings suggest that aerial parts of Teucrium polium methanolic extract could be used as natural source of antioxidants in food, pharmaceutical and cosmetic industry.