Abstract:
Mentha is a genus belonging to the family of Lamiaceae, whose plants are among the most aromatic and spread in diverse environments worldwide. The aim of this study is to evaluate the total phenolics and flavonoids contents and the in vitro antioxidant activities of aqueous and ethanolic extract of Mentha suaveolens. The Folin–Ciocalteu method was used to determine the total phenols content while flavonoids were estimated according to the aluminum chloride colorimetric method. Also the antioxidant activities were determined by two methods: 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging and β-carotene linoleic acid. The total polyphenols content of the aqueous extract was 240.66±30.42µg GAE/ mgE and flavonoids were 18.35±0.57µg QE/mgE. The total polyphenols content of the ethanolic extract was 219.217±20.63µg GAE/mgE and flavonoids were 20.59±0.6µg QE/ mgE. In the DPPH assay the aqueous extract showed the higher scavenging capacity (IC₅₀ = 0.035 ± 0.001 mg/ml), followed by ethanolic extract with IC₅₀ of 0.049 ± 0.000 mg/ml. In the test of β-carotene /linoleic acid, the percentage of inhibition was 66.954 ± 2.64% of aqueous extract and 74.329 ± 2.03% of ethanolic extract.

Keywords: Mentha suaveolens, Antioxidant Activity, Polyphenols, DPPH Scavenging, Β-Carotene.