Antioxidant, antifungal and insecticidal activities of essential oil (EO) extracted from the Moroccan lavender (Lavandula dentata) were investigated and their chemical constituents determined. Gas chromatography with flame ionization detection (GC-FID) and gas chromatography-mass spectrometry analyses (GC-MS) were used to examine the phytochemical composition of EO. Antioxidant potential was examined in vitro by use of three tests: DPPH inhibition, reducing power (FRAP) and total antioxidant capacity (TAC). Antifungal activity was assessed by calculating inhibition of growth of Alternaria alternata, Botrytis cinerea and Fusarium oxysporum. Repellent potential and toxicity of EO by contact and inhalation were performed against Callosobruchus maculatus. Sixteen constituents were detected in the EO of Lavandula dentata. The major component was linalool (45.06%) followed by camphor (15.62%) and borneol (8.28%). EO exhibited a significant antioxidant activity, as measured by DPPH and FRAP assays, with IC50 and EC50 values of 12.95 ± 1.300 mg/mL and 11.88 ± 0.23 mg/mL, respectively. EO of lavender exhibited total antioxidant capacity of 81.28 ± 2.28 mg AAE/g EO. EO of lavender showed an inhibitory effect on mycelial growth against tested fungi and was 100% in the case of B. cinerea. EO caused total mortality of adult C. maculatus from 5 µL/L air with LC50 value of 4.01 µL/L air. Significant reduction in numbers of eggs laid (99.2%) and emergence (100%) was observed in a dose-dependent manner up to maxima of 100% and 99.2%, respectively. EO of lavender also showed a moderate potency to repel insects with a mean of 34.44%. EO of Moroccan Lavandula dentata has potential to be an effective natural agent against free radical damage and could be an environmentally friendly alternative bio-fungicide and bio-insecticide.

Essential oils (EO) of Origanum compactum Benth. (O. compactum) are well known for their biological and pharmacological activities. This study aimed to assess the chemical composition, antifungal, insecticidal and repellent activities of EO of O. compactum used in the Mediterranean diet. Phytochemical screening was conducted using gas chromatography-mass spectrometry (GC/MS). Antifungal activity was tested by the disc diffusion method followed by a minimal inhibitory concentration (MIC) assay against Candida albicans (C. albicans), Aspergillus flavus (A. flavus), Aspergillus niger (A. nige), and Fusarium oxysporum (F. oxysporum). Repellent potential and toxicity of EO by contact and inhalation were tested against Callosobruchus maculatus (C. maculatus). The yield of essential oil obtained by hydrodistillation of O. compactum was 4.41 ± 0.35%, mainly composed of Carvacrol (38%) and Thymol (31.46%). Regarding antifungal activity, the results revealed a wide antifungal spectrum of the studied EO against the tested strains, which reached 100% growth inhibition, especially against A. niger and C. albicans even at the lowest MIC values (3.125 μg/mL). Concerning insecticidal activity, the EO caused total mortality of C. maculatus adults at a dose of 20 μL/L air with LC50 value of 5.3 μL/L air. A significant reduction in the number of eggs and emergence was proportionally recorded with increasing doses up to 100% at 20 μL/L air. For repellent activity, the studied EO showed a moderate repellent activity with an average percentage of 39.16%. The outcome of this work revealed that O. Compactum EO could be a sustainable and environmentally friendly alternative bioinsecticide and bio-fungicide to replace the chemically synthesized forms.

Food is always subjected to microbial infection and lipid peroxidation, which frequently leads to serious food intoxications. In the present study, essential oils (EOs) extracted from Lavandula dentata Moroccan species and its major component (linalool) were chemically characterized and their antioxidant potential and antibacterial properties against foodborne pathogenic bacteria were examined. EOs phytochemical profile was carried out using gas chromatography-mass spectrometry analysis (GC-MS). The antioxidant potential was evaluated, in vitro, by use of the β-carotene discoloration assay and in silico vs. NADPH oxidase enzymatic complex as an antioxidant marker. The antibacterial proprieties were assessed by use of minimal inhibitory concentration (MIC) and disc diffusion methods, against Gram (−) bacteria (Pseudomonas aeruginosa, Salmonella enterica, and Escherichia coli) and Gram (+) bacteria (Bacillus subtilis and Staphylococcus aureus). Linalool (49.71%) was the major component among the eighteen components identified in Lavandula dentate EO, followed by camphor (14.36%) and borneol (8.21%). The studied EO and linalool compounds showed important antioxidant activity through the β-carotene discoloration test with IC50 values of 35.72 ± 1.21 mg/mL and 30.32 ± 1.23 mg/mL, respectively. Among all the analyzed compounds of lavender EOs, thymol, carvacrol, and α-terpineol were the most active compounds against NADPH oxidase with a glide score of −6.483, −6.17, and −4.728 kcal/mol, respectively. 2D and 3D views showed the formation of hydrogen bonds between the most active compounds and the active site of NADPH oxidase. The antibacterial data showed a significant activity of Lavandula dentata essences against tested foodborne pathogenic bacteria, especially against S. aureus and B. subtilis. Linalool proved active toward the same bacteria and had closer activity to that of lavender essential oil. In light of the obtained findings, the essential oil of Lavandula dentata Moroccan species can be used in the packaging sector as a promising natural food conservative to limit lipid oxidation and treat foodborne infections.

Callosobruchus maculatus (Fab.) (C. maculatus) is one of the major pests of legume seeds in storage causing significant damage, leading to food insecurity and low income for farmers. This work was planned to develop eco-friendly agents from essential oils of Artemisia herba alba Asso. (AEO), Maticaria Recutita L. (MEO), and Dittrichia Viscosa L. (DEO) to control C. maculatus. To achieve this goal, essential oils (EOs) were extracted by hydro-distillation using Clevenger apparatus before being characterized by GC-MS. EOs were used for testing purposes using three different tests, namely, inhalation toxicity, contact toxicity, and repellency tests. GC-MS analysis of EOs showed the presence of 16 potentially active compounds in AEO and 38 in MEO, whilst 15 compounds were identified in DEO. AEO was higher in thujone (57.6%) and chrysanthenone (11.8%). Santolina alcohol (40.7%) and germacrene D (8.9%) were the major compounds identified in MEO, whereas isocostic acid (72.3%) was the chief compound of DEO. The obtained findings showed that the studied EOs showed considerable insecticidal activity against C. maculatus with a lethal dose (LC50) of 3.78, 8.86, and 14.34 μL/1 liter of air by AEO, MEO, and DEO, respectively. At 1 μL/1 liter of air, the oviposition reduction rate was 90.02%, 70.65%, and 48.23% by AEO, MEO, and DEO, respectively, whereas the emergence reduction rate was 87.32%, 60.08%, and 32.24% by AEO, MEO, and DEO, respectively. With increasing doses up to 20 μL/L, the reduction of individual emergence reached 98.8% by AEO of 24 h after treatment. AEO, MEO, and DEO showed significant repellent effects against adults of C. maculatus with repulsion percentages of 60.83%, 50.83%, and 72.5%, respectively. The outcome of this work suggests that the essential oils of the studied plants, particularly Artemisia herba alba Asso. oils, can constitute a natural and environmentally friendly alternative to develop new bioinsecticides for the control of C. maculatus.

This study was performed to investigate the phytochemical profile, and the, in vitro, and, in silico, antioxidant and antibacterial properties of the essential oil (EO) extracted from Origanum compactum. EO phytochemical screening was examined by gas chromatography coupled to mass spectrometry. The antioxidant potential, in vitro, was assessed using reducing power(FRAP), free 2,2 diphenylpicrylhydrazyl (DPPH) radical scavenging and total antioxidant capacity tests. Antibacterial properties against two Gram (−) and two Gram (+) bacteria were assessed using the minimal inhibitory concentration (MIC) and the disc diffusion methods. By use of molecular docking, antioxidant and antibacterial activities of oregano EO were also tested. Thymol (75.53%) was the major compound among the nine compounds identified in the EO of Origanum compactum, followed by carvacrol (18.26%). Oregano EO showed an important antioxidant capacity, as tested by FRAP and DPPH assays, with EC50 and IC50 values of 13.300 ± 0.200 and 0.690 ± 0.062 mg/mL, respectively. The same EO has a total antioxidant capacity of 173.900 ± 7.231 mg AAE/g EO. The antibacterial results showed significant activity of Origanum compactum EO against all tested bacteria, especially against S. aureus (MIC = 0.25 mg/mL) and B. subtilis (MIC = 0.06 mg/mL). In silico, carvacrol was the most active molecule against nicotinamide adenine dinucleotide phosphate oxidase (2CDU) and S. aureus nucleoside diphosphate kinase (3Q8U) with a glide score of −6.082, and −6.039 kcal/mol, respectively. Regarding the inhibition of E. coli beta-ketoacyl-[acyl carrier protein] synthase (1FJ4), piperitenone was the most active molecule with a glide score of −7.112 kcal/mol. In light of the results obtained, the EO of Origanum compactum Moroccan species can be used as promising natural food conservatives and an agent to fight antibiotic-resistant nosocomial microbes.

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