Les propriétés biologiques des huiles essentielles de Curcuma longa, Ammoides verticillata et Thymus ciliatus ssp. eu-ciliatus.

Abstract

The aim of this study is to determine the chemical composition and the in vitro biological properties (antioxidant, antimicrobial, anti-inflammatory and anti-diabetic) of two plants essential oils originated from the north-west of Algeria (Tlemcen) (Ammoïdes (or Ptychotis) verticillata (Desf.) Briq. and Thymus munbyanus subsp. ciliatus (Desf.) Greuter & Burdet); and also commercial Curcuma longa. The chemical composition was determined using gas chromatography coupled to mass spectrometry. Different tests were used to evaluate in vitro the antioxidant activity. The antimicrobial activity was evaluated by the disc diffusion method and the minimal inhibition concentration was determined by the microdilution method. The effect of these essential oils was also studied on lipoxygenase, acetylcholinesterase and alphaamylase. According to the chemical analysis results, carvacrol is the major compound of T. ciliatus ssp. eu-ciliatus (71.4%), followed by p-cymene (8.3%) and γ-terpinene (5.9%). Cumin alcohol represents 44.3% of the essential oils of A. verticillata, γ-terpinene (18,1%), limonene (14,2%) and thymol (10,8%). The major compound of C. longa was aromatic tumerone (35%), Curlone (14,2%) and tumerone (11,8%). The essential oils of T. ciliatus exhibit a good antimicrobial activity against Staphylococcus aureus (12.5 to 13.83 mm), Listeria monocytogenes (13.83 to 22.5 mm), Escherichia coli (13.79 to 14.67 mm) and Salmonella Thyphimurium (15.67 mm). These essential oils had also a good activity against the hydroxyl radical (IC50=0,00221mg/ mL), Oxygen Radical Antioxidant Capacity or ORAC (IC50 =1,19 mM Trolox/g), and also inhibited the activity of both enzymes acetylcholinesterase and alphaamylase. On the other hand the anti-radical activity of the essential oils of A. verticillata were effective against DPPH (IC50=0,0422mg/mL), ABTS (IC50=0,0013 mg/mL), TBARS (IC50=0,0279 mg/mL). But the most powerful effect was on H2O2 (IC50=0,522mg/ml). It has a good reducing property and ability to protect the liposomal membranes against lipid peroxidation (IC50=0,299 mg/mL). The essential oils of C. longa had a good capacity of lipoxygenase inhibition (IC50=0,013 mg/mL). The anti-tumor activity of T. ciliatus against cancer cells THP-1 was higher than A. verticillata. These essential oils showed an interesting biological properties that should be investigated in vivo.