In vitro antioxidant and antimicrobial activity of some Lamiaceae species

Abstract

The methanolic extracts, infusions, decoctions and hydrosols of six plants were investigated for their total phenolic contents, antioxidant and antimicrobial activities: Mentha piperita (Peppermint), Thymus vulgaris (thyme), Melissa officinalis (lemon balm), Ocimum basilicum (basil), Rosmarinus officinalis (rosemary) and Salvia officinalis (sage) (Lamiaceae). Total phenolic contents were determined by Folin-Ciocalteu procedure and ranged from 111.03 +/- 0.6 (sage methanolic extract) to 19.07 +/- 0.0 mg (basil methanolic extract) gallic acid equivalent /g extract. The antioxidant activity was evaluated by two methods, DPPH and phosphomolybdenum assays. The decoction of rosemary showed the highest DPPH radical scavenging activity (IC50 = 8.36 mu g/mL). The methanolic extract of Peppermint showed the highest total antioxidant activity (241.85 +/- 1.9 mg ascorbic acid equivalent /g extract) measured by phosphomolybdenum assay. The antimicrobial activities of herbs were tested against eight bacteria and two yeasts.