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To help discover a reasonable and eco-friendly insecticide, we undertook a study on the insecticidal potential of carvacrol and essential oils extracted by hydrodistillation using a Clevenger apparatus from the plant species Nigella sativa seeds essential oils of Nigella sativa (EONS) on Callosobruchus maculatus adults. Several tests including contact toxicity, repellent effect, topical contact test, and inhalation effect were conducted. Adults of C. maculatus have been exposed to the toxic effects of different concentrations of these essential oils as well as with carvacrol. The results obtained showed that both EONS and carvacrol exhibited a moderate repellent effect (class II) on C. maculatus adults. EONS showed the highest toxicity by inhalation test, with an LD50 of 13.386 and an LD95 of 33.186 μL/cm2, compared to carvacrol (LD50 = 21.509 and LD95 = 38.877 μL/cm2). The EONS by contact test exhibited more toxic effects, with an LD50 of 23.350 µL/100 g and an LD95 of 45.315 µL/100 g, compared to carvacrol (LD50 = 27.853 µL/100 g and LD95 = 45.184 µL/100 g). For the topical contact test results, carvacrol was more toxic, with an LD50 of 3.915 and an LD95 of 7.696 µL/mL, compared to EONS (LD50 = 14.509 and LD95 = 25.516 µL/mL). The high toxicity of EONS can be explained by the presence of 25.8% of o-cymene, 8.53% of cyclofenchene, and 7.71% of beta-pinene, as well as 4.6% of carvacrol, in its chemical composition. Unmitigatedly, these data suggest that the essential oils of N. sativa may present a raw material for the development of new bio-insecticidal products against C. maculatus, one of the main pests of stored foodstuffs.

Cytisus villosus Pourr. (C. villosus) is a medicinal plant belonging to the Fabaceae family, which grows in the Mediterranean area. It is used in traditional medicine against diseases related to inflammation. The objective of the present study was to identify the mineral and polyphenolic composition as well as to evaluate some biological properties including antioxidant, anti-inflammatory, and analgesic activities of C. villosus leaf aqueous extract. The chemical constituents were identified and quantified using ultra performance liquid chromatography-electrospray ionization tandem mass spectrometry (UPLC-ESI-MS/MS) methods. The antioxidant properties of C. villosus leaves were tested using reducing power (RP), 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), and 2,2′-diphenyl-1-picrylhydrazyl (DPPH) assays. The anti-inflammatory potency was evaluated in vitro and in vivo using the albumin denaturation test and the carrageenan test, respectively. Furthermore, the analgesic effect was performed in vivo using tail flick, acetic acid-induced contortion, and plantar tests. Mineralogical analysis revealed that potassium and calcium were the most abundant minerals. The analysis and quantification of the phytochemical composition using UPLC-ESI-MS/MS showed that quinic acid (57.478 ± 1.72 mg/kg) was the major compound of the aqueous extract, followed by salicylic acid (17.38 ± 0.2 mg/kg), isoquercetin (16.895 ± 1.01 mg/kg), and gallic acid (15.914 ± 1.51 mg/kg). The extracts showed potent antioxidant activity for all tests used. The highest antioxidant activity was recorded for the DPPH, ABTS and RP methods, with an IC50 of 3.94 ± 0.09, 2.88 ± 0.07, and 1.94 ± 0.10 μg/mL, respectively. Additionally, using the most frequent analgesic assays, the aqueous extract at a dose of 500 mg/kg exhibited a potent analgesic activity. Notably, an interesting inhibition of albumin denaturation was recorded with an IC50 of 383.94 μg/mL, corroborating the in vivo test. Overall, the results presented here may represent a scientific basis for the traditional use of C. villosus in the treatment of inflammation-related diseases.

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 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.

Multiple stresses in waste dumpsite soils can drive antibiotic production as one of the strategies for survival. Bacteria are the most prolific producers of antibiotics. This study investigated the antibiotic production potential of bacteria isolated from Bahir Dar city municipal solid waste dumpsite (MSWDS). Bacteria were isolated from soil collected from the dumpsite on starch casein or nutrient agar. The isolates were carefully screened for antimicrobial activity against six pathogenic bacterial test strains. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were also determined from cell-free metabolites of the most promising isolates. Isolates showing antimicrobial activity were identified using cultural and biochemical methods. A total of 143 distinctive colonies were obtained and tentatively identified to 13 bacterial genera. Twenty-six (18.18%) of the isolates (six Bacillus and 20 actinobacteria related) demonstrated antimicrobial activities at least against one of the tested bacterial strains. These isolates were related to two actinobacterial and 11 other bacterial genera. Seven out of 26 isolates showed a broad-spectrum of antibiotic activities. Two isolates, which showed a wide spectrum, were selected for the MIC and MBC tests against Escherichia coli and Staphylococcus aureus. The MIC and MBC of the isolates were recorded to be 250–500 µg/mL against the test strains. Bahir Dar city MSWDS contained a high incidence of antibiotic-producing bacteria. Strain level identification of the isolates and detailed characterization of the metabolites will give a good insight into the antimicrobial production potential in the waste dumpsite.

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.