The antioxidant, antibacterial and antifungal properties of essential oils (EOs) of Juniperus thurifera L., a plant utilized in traditional, herbal medicine, were investigated. The EOs were extracted by use of a Clevenger apparatus and phytochemicals identified by gas chromatography coupled with mass spectrometry (GC/MS/MS). The antioxidant capacity of EOs of J. thurifera was determined by 2,2-diphenyl-1-picrylhydrazil (DPPH), total antioxidant capacity (TAC), and ferric reducing antioxidant power (FRAP). Antimicrobial activity of EOs of J. thurifera was determined against four fungal strains, Candida albicans; ATCC 10231, Aspergillus niger; MTCC 282, Aspergillus flavus; MTCC 9606 and Fusarium oxysporum; MTCC 9913 and four bacterial strains, Staphylococcus aureus; ATCC 6633, Escherichia coli; K12, Bacillus subtilis; DSM 6333, and Pseudomonas aeruginosa; CIP A22, by use of the disk diffusion method, and microdilution method used to determine the minimum inhibitory concentration (MIC). EOs of J. thurifera consisted of 31 compounds and were dominated by α-thujene (25%), elemol (12%) and muurolol (12%). Antioxidant activity recorded an IC50 of 24 ± 0.71 µg/mL (DPPF), EC50 of 0.19 ± 0.01 mg/mL (FRAP), and 9.3 × 102 ± 38 mg EAA/g (TAC). The EOs of J. thurifera exhibited significant antibacterial activity against all bacterial strains under investigation, especially P. aeruginosa; CIP A22 with an inhibition diameter of 28 ± 1.5 mm and MIC of 4.8 × 10 −2 ± 0. 001 µg/mL. EOs of J. thurifera also exhibited significant antifungal activity against C. albicans; ATCC 10231 and F. oxysporum; MTCC 9913 with an activity of 21 ± 2.1 mm, 32 ± 2.3%, and MIC of 9.5 × 10 −2 ± 0.001 Bioactive molecules found in EOs of J. thurifera could be used as an alternative solution to antibiotics available on the market to combat microbial resistance.

Artemisia annua (AA) is an aromatic plant belonging to the Asteraceae family, which has long been known for its several medicinal virtues. In addition, essential oils (EOs) extracted from AA have a wide range of therapeutic properties. Therefore, this study aimed to investigate the phytochemical composition, anti-microbial, and anti-oxidant properties of Artemisia annua essential oil (EOAA). EO was extracted, and its chemical constituents were ascertained by the use of GC-MS analysis. EOAA shows remarkable antioxidant capacities of DPPH free radical scavenging with an IC50 value of 29 ± 5.3 μg/mL and ferric reducing antioxidant power with an EC50 value of 9.21 ± 0.3 µg/mL, and it also has a good total antioxidant capacity of 911.59 ± 115.71 milligrams of ascorbic acid equivalence per gram of EO (mg AAE/g EO). Moreover, the in vitro antimicrobial screening results indicate that EOAA has shown promising antibacterial activity, especially against the Escherichia coli strain, and it also shows significant antifungal activity against Fusarium oxysporum and Candida albicans yeasts. Taken together, our findings highlight the importance of EOAA as a source of strong antioxidant and antimicrobial agents, which could be used as an alternative form to control free radicals and combat drug-resistant microbes.

Juniperus thurifera is a native species to the mountains of the western Mediterranean region. It is used in traditional medicine as a natural treatment against infections. The present study aimed to carry out the chemical analysis and evaluate the antioxidant, antimicrobial, as well as in silico inhibition studies of the essential oils from Juniperus thurifera bark (EOEJT). Chemical characterization of EOEJT was done by gas chromatography (GC-MS). We have performed three antioxidant assays (Reducing power (FRAP), 2, 2-diphenylpicrylhydrazyl (DPPH), and total antioxidant capacity (TAC)) of the EOEJT. We next evaluated the antimicrobial activity against in silico study, which was carried out to help evaluate the inhibitory effect of EOEJT against NADPH oxidase. Results of the GC/MS analysis revealed seven major compounds in EOEJT wherein muurolol (36%) and elemol (26%) were the major components. Moreover, EOEJT possessed interesting antioxidant potential with an IC50 respectively of 21.25 ± 1.02 μg/mL, 481.02 ± 5.25 μg/mL, and 271 μg EAA/mg in DPPH, FRAP, and total antioxidant capacity systems. Molecular docking of EOEJT in NADPH oxidase active site showed inhibitory activity of α-cadinol and muurolol with a glide score of −6.041 and −5.956 Kcal/mol, respectively. As regards the antibacterial and antifungal capacities, EOEJT was active against all tested bacteria and all fungi, notably, against Escherichia coli K12 with an inhibition diameter of 21 mm and a MIC value of 0.67 mg/mL, as well as against Proteus mirabilis ATCC 29906 with an inhibition diameter of 18.33 ± 1.15 mm and a MIC value of 1.34 mg/mL. A more pronounced effect was recorded for the fungal pathogens Fusarium oxysporum MTCC 9913 with inhibition of 37.44 ± 0.28% and MIC value of 6.45 mg/mL, as well as against Candida albicans ATCC 10231 with an inhibition diameter of 20.33 ± 1.15 mm and a MIC value of 0.67 ± 0.00 mg/mL. Altogether, these results highlight the importance of EOEJT as a source of natural antibacterial and antioxidant drugs to fight clinically important pathogenic strains.

Juniperus phoenicea (L.) is a medicinal plant that has been used in phytotherapy as a treatment of certain pathological infections. In this context, the present work aimed to valorize the essential oil of J. phoenicea seeds (EOGP) by studying its chemical composition, and antioxidant and antimicrobial activities. The EOGP was extracted by use of hydrodistillation and characterized by gas chromatography (GC–MS). The antioxidant power was evaluated by three methods (TAC, DPPH, and FRAP). The antimicrobial power was evaluated against Staphylococcus aureus (ATCC6633), Escherichia coli (K12), Bacillus subtilis (DSM6333), Proteus mirabilis (ATCC29906), Candida albicans (ATCC10231), Aspergillus niger (MTCC282), Aspergillus flavus (MTCC9606), and Fusarium oxysporum (MTCC9913). The GC/MS results revealed a total identification of 99.98% with a dominance of carvacrol (39.81%) followed by p-cymen-3-ol (34.44%) and o-cymene (13.60%). Findings showed that EOGP exhibited important antioxidant power as IC50 was determined to be 26 µg/mL for 2,2-diphenyl-1-picrylhydrazyl, while EC50 was 216.34 µg/mL for ferric reducing antioxidant power and total antioxidant capacity was 720 mg AAE/g. The antimicrobial power on solid medium revealed that the inhibition diameters ranged from 11.30 ± 0.58 to 20 mm for the bacterial strains and from 9.33 ± 0.57 to 54.43 ± 0.29 mm for fungi. Notably, minimum inhibitory concentrations ranged from 18 to 19 µg/mL for bacterial strains and from 5.04 to 10.09 µg/mL for fungal strains. Overall, our results demonstrated the importance of EOGP as a source of natural antioxidant and antibacterial medicines against clinically relevant pathogenic strains.

The present study investigated the antioxidant and antimicrobial activities as well as characterized the chemical composition of the essential oils (EO) isolated from Artemisia flahaultii (EOF). EOF was extracted using hydro-distillation, and the chemical composition of EOF was ascertained by gas chromatography coupled with mass spectrometry (GC/MS). To assess antioxidant capacity, three tests were used: the 2,2-diphenyl-1-picrylhydrazil (DPPH), the total antioxidant capacity (TAC) and the ferric-reducing antioxidant power (FRAP) test. The antimicrobial activity of EOF was investigated using the diffusion assay and minimal inhibitory concentration assays (MICs). By use of in silico structure–activity simulations, the inhibitory potency against nicotinamide adenine dinucleotide phosphate (NADPH), physicochemical characters, pharmaco-centric properties and absorption, distribution, metabolism, excretion (ADME) characteristics of EOF were determined. GC/MS analysis reveals 25 components majorly composed of D-Limonene (22.09%) followed by β-pinene (15.22%), O-cymene (11.72%), β-vinylnaphthalene (10.47%) and benzene 2,4-pentadiynyl (9.04%). The capacity of DPPH scavenging by EOF scored an IC50 of 16.00 ± 0.20 µg/mL. TAC revealed that the examined oils contained considerable amounts of antioxidants, which were determined to be 1094.190 ± 31.515 mg ascorbic acid equivalents (AAE)/g EO. Results of the FRAP method showed that EOF exhibited activity with EC50 = 6.20 ± 0.60 µg/mL. Values for minimal inhibitory concentration (MIC) against certain clinically important pathogenic bacteria demonstrate EOF’s potent antibacterial activity. MIC values of 1.34, 1.79, and 4.47 μg/mL against E. coli, B. subtilis and S. aureus were observed respectively. EOF exhibited significant antifungal activities against two stains of fungi: F. oxysporum and C. albicans, with values of 10.70 and 2.23 μg/mL, respectively. Of the total, 25 essential oils were identified. 2,4-Di-tert-butylphenol and capillin were the most active molecules against NADPH. The ADME prediction revealed that EOF was characterized by useful physicochemical characteristics and pharmaco-centric properties. The findings of this study show that the EOF can be used as an alternative to treat microbial resistance. Based on the in silico studies, EOF can be used as an “eco-friendly” NADPH inhibitor.

The objective of this work was to characterize the phytochemical composition of essential oil from Juniperus thurifera (L.) fruits (EOFT) and study its antioxidant, antibacterial, and antifungal effects. EOFT was extracted by hydrodistillation and fingerprinted by using GC–MS. The antioxidant effect of EOFT was evaluated using 2,2-diphenylpicrylhydrazyl (DPPH), ferric iron reduction assay (FRAP), and total antioxidant capacity (TAC) assays. Importantly, the antimicrobial activity of EOFT was performed against Candida albicans, Aspergillus niger, Aspergillus flavus, Fusarium oxysporum, Staphylococcus aureus, Escherichia coli, Bacillus subtilis, and Proteus mirabilis. In addition, the inhibitory capacity of NADPH oxidase and human acetylcholinesterase was also investigated using molecular docking. The results of the chemical composition reveal that EOFT constituted 11 terpenic compounds with dominance of elemol (33.86%), terpinen-4-ol (27.80%), and cryptomeridiol (18.36%). The antioxidant power of EOFT recorded IC50 values of 197.07 ± 0.09 μg/mL (DPPH) and 216.34 ± 0.06 μg/mL (FRAP), while TAC of EOFT was determined to be 181.06 μg AAE/mg. The antibacterial potency on solid medium revealed that EOFT induced inhibition zone diameters reaching 14 mm, and a minimum concentration up to 2.78 µg/mL against the studied bacterial strains. The EOFT also showed an important antifungal effect as the inhibition reached 42%, and the MIC was between 7.50 and 22.25 µg/mL. The in silico study showed that o-Cymene was the most active molecule against NAD(P)H oxidase followed by cadinol with a Glide score of −5.344 and −5.143 kcal/mol, respectively. Due to their promising results, the outcome of this work suggests that EOFT could be used as an interesting natural weapon to control microbial and freed radical-related diseases.