Abstract

This study aimed to quantify the active biological compounds in Origanum vulgare subsp.glandulosum Desf. Analysis of the chemical composition essential oil from Tunisia was carried out using gas chromatography-mass spectral (GC-MS). The antioxidant capacities of essential oil and extracts were evaluated using free radical scavenging, ferric reducing antioxidant power assay and metal chelating effects. The antidiabetic activity was screened using α-amylase. The oil was dominated by carvacrol (61.20 to 74.03), p-cymene (5.89 to 12.60), and g-terpinene (1.13 to 6.88). 1,1-diphenyl-2-picrylhydrazyl (DPPH) and ferric reducing antioxidant power assay (FRAP) assays showed that leaves of O. vulgare have a potent antioxidant activities which was comparable to Trolox. The methanol extract have the highest ion chelating ability at around 76.98 mg equivalent ethylenediaminetetraacetic acid (EDTA)/g dry matter (DM).  The amounts of chlorophylls A and B were higher than that of lycopene and β-carotene. Essential oils and extracts, screened for α-amylase inhibitory effect, showed a strong capacity to inhibit the degradation of starch by pancreatic and salivary α-amylase. Extracts and essential oils of O. vulgare showed substantial antioxidant activity, and detectible inhibitory effect on α-amylase activity, therefore it could be used as a natural preservative ingredient in food and/or pharmaceutical industries.

Key words: Origanum vulgare subsp. glandulosum, essential oil, solvent extract, biological activities.