Plants of the Lamiaceae family are widely used for medicinal, cosmetic and culinary purposes. Phenolic compounds such as flavonoids and tannins are the main constituents of these plants; they have a proven multidirectional biological activity. Polyphenols have exceptional antioxidant potential, and they can intervene in the prevention of many health disorders. This work aims to study the composition and antioxidant power of phenolic compounds from crude extracts and fractions of Origanum elongatum leaves. This specie was subjected to phytochemical study through precipitation, turbidity and coloring reactions to highlight their secondary metabolites qualitative composition. Polyphenolic extraction was made by Soxhlet using two solvents: methanol 70%, ethanol 70%. Then, methanol’s crude was fractionated with solvents having escalating polarity; ethyl acetate, n-butanol. The polyphenols and flavonoids contents were spectrophotometrically estimated using Folin-Ciocalteau and Aluminum Trichloride methods. The antioxidant power of crude and fractionated extracts was evaluated by diphenyl-picryl-hydrazyl (DPPH●) and iron (FRAP) tests. The screening tests showed the existence of polyphenols, mucilages, sterols and triterpenes, oses and holosides. The highest yield of extraction is obtained by 70% methanol, with an average of 32.29%. Quantitative assays indicated that the hydroethanolic extract and the ethyl acetate fraction possessed high amount of polyphenols and flavonoids compared with other fractions and subsequently exhibited a marked scavenging activity on DPPH radical (IC50 = 0,085±0,002 and 0,112±0,003 mg/ml, respectively) and high reductive ability on ferric ion assay with IC50 = 0,181±0,004 mg/ml, 0,291±0,005 mg/ml, respectively.

Thymus capitatus and Thymus broussonnetii are two Moroccan endemic medicinal plants used traditionally by the local population. The present study aims to investigate their essential oil chemical composition, antioxidant and antibacterial activities. The chemical composition of the essential oils was determined using the GC-MS analysis, the antioxidant activity assessed using DPPH and FRAP methods while the antimicrobial activity was evaluated against nine bacteria species tested (Enterococcus faecalis, Serratia fonticola, Acinetobacter baumannii, Klebsiella oxytoca, sensitive Klebsiella pneumoniae, sensitive Escherichia coli, resistant Escherichia coli, resistant Staphylococcus aureus and Enterobacter aerogenes). The major identified compounds of T. capitatus essential oil where carvacrol (75%) and p-cymene (10.58%) while carvacrol (60.79%), thymol (12.9%), p-cymene (6.21%) and γ-terpinene (4.47%) are the main compounds in T. broussonnetii essential oil. The bioactivity of the essential oils of the two species of thyme was explained by their richness in oxygenated monoterpenes known for their great effectiveness with an IC50 of 3.48 ± 0.05 and 4.88 ± 0.04 μL/mL and EC50 of 0.12 ± 0.01 and 0.20 ± 0.02 μL/mL in the DPPH and FRAP assays, respectively, with an important antibacterial activity. These results encourage the use of these plants as a source of natural antioxidants, and antibacterial additives, to protect food from oxidative damage and to eliminate bacteria that are responsible for nosocomial infections.

The aim of this research is to profile the chemical composition of the essential oil (EO) extracted from the aerial parts of Origanum elongatum (O. elongatum) and to evaluate its antioxidant, antibacterial and insecticidal activities on Ceratitis capitata adults. Gas chromatography coupled with mass spectrometry (GC/MS) revealed a total of 27 constituents in EO of O. elongatum, which accounted for 99.08% of its constituents. Carvacrol (57.32%) was a main component, followed by p-cymene (14.70%) and γ-terpinene (9.84%). The antioxidant activity of O. elongatum EO was investigated using DPPH (1,1-diphenyl-2-picrylhydrazyl), FRAP (Ferric reducing antioxidant power), and TCA (the total antioxidant capacity) methods. This EO exhibited a remarkable antiradical and reducing power against DPPH (IC50 = 2.855 ± 0.018μL/mL), FRAP (EC0.5 = 0.124 ± 0.013µL/mL) and TCA (IC50 = 14.099 ± 0.389 mg AAE/g of the EO). The antibacterial tests in vitro, using the disc and dilution methods, were carried out on nine pathogenic bacteria isolated from the hospital patients, such as Enterococcus faecalis, Serratia fonticola, Staphylococcus aureus, Acinétobacter baumannii, Klebsiella oxytoca, Klebsiella pneumoniae sensible, E.coli sensible, E.coli resistante, and Enterobacter aerogenes. The EO demonstrated a considerable antibacterial activity with minimum inhibitory concentrations (MIC) from 2 to 8 µL/mL against all strains except Staphylococcus aureus (MIC = 32 µL/mL). Regarding the insecticidal activity, the fumigation test indicated a high efficacy (100% mortality), and a lethal dose of LD50  =  17 ± 0.53 μL/L air was found after 24 h of exposureTherefore, O. elongatum EO could be utilized as a natural antioxidant, antibiotic and biopesticides.

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The objective of this study was to identify new bioactive substances through the phytochemical study and evaluation of the antibacterial activity of the essential oils of Tetraclinis articulata (Vahl). Harvested in April 2016, in the region of Khenifra (Middle Atlas-Morocco). Separate of hydrodistillation extracts of the three organs (branches, leaves and fruits) of Tetraclinis articulate were performed. The yields of essential oils are 0.92% for fruits; 0.41% for branches and 0.61% for leaves. The GC/MS analysis allowed the identification of 33 compounds in essential oil leaves, 20 compounds in excess fruits and 58 compounds in branches. The main compounds are bornyl acetate (38.54%) and α-pinene (6.71%) for leaves. α-pinene (22.12%); 13-epi-mannol (3.58%) and retinol (3.44%) for branches. Bornyl acetate (19.96%); α-pinene (12.47%) and retinol (11.98%) for fruits. The antibacterial properties of the essential oil of leaves of Tetraclinis articulata (Vahl) were tested in clinical bacterial strain. The essential oils inhibit the growth of Escherichia coli, Staphylococcus aureus and Klebsiella pneumoniae at 1.2 µl/ml; 2.4 µl/ml and 9.7 µl/ml respectively. Indeed, the resistance of bacteria to antibiotics is known for its adverse effects on human health, to escape this problem, it is necessary to exploit the antibiotics from aromatic and medicinal plants.