Mustapha Larhsini

Objective: The present study aimed to characterize the phytochemical composition, the antioxidant and antimicrobial potencies of two essential oils obtained from the Moroccan ecotypes A. maroccanus and A. radiatus. Methods: The chemical composition of EOs was analysed by means of Gas Chromatography-Mass Spectroscopy analysis (GC-MS); moreover, 2,2-diphenyl-1-picrylhydrazyl (DPPH) and reducing power assays ware made to evaluate the antioxidant activity. In addition, disk diffusion method, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) were employed to evaluate the antimicrobial activities against some resistant and pathogenic microorganism strains. Results: Results showed that the Anacyclus maroccanus and Anacyclus radiatus EOs were characterized by high amounts of oxygenated monoterpenes and sesquiterpenes, along with radical scavenging and reducing properties. Furthermore, EOs exhibited marked antimicrobial effects against all the tested bacterial and fungal strains. Conclusion: The current findings suggest that EOs from Anacyclus maroccanus and Anacyclus radiatus Moroccan ecotypes are a promising source of natural antioxidants that could be used in the pharmaceutical industry, particularly against drug-resistant microbial strains.

In this study, chemical profile, antioxidant potential and antimicrobial interactions with conventional antimicrobials of essential oil (EO) isolated from Cladanthus scariosus aerial parts were investigated. The EO was analyzed by GC-MS (Gas Chromatography-Mass spectrometry). Forty-three components representing 98.7% of the oil were identified. The main components were o-cymene, caryophyllene oxide, γ-terpinene and α-sabinene. Furthermore, the antioxidant and antimicrobial activities against ten bacteria and two Candida strains were assessed. The results showed an interesting antioxidant effect with IC₅₀ of 1.04 ± 0.04 mg/mL, 0.55 ± 0.01 mg/mL and 0.36 ± 0.14 mg/mL, respectively, for DPPH (2,2-Diphenyl-1-Picrylhydrazyl), FRAP (Ferric-Reducing-Ability-Power), and ABTS (2-2’azinobis-3-ethylbenzothiazoline-6-sulphonate) methods. The EO exhibited a strong antimicrobial activity, especially against Methicillin-resistant Staphylococcus aureus and Candida glabrata. In combination with antimicrobials, the studied EO revealed a high synergism effect in reducing gentamicin MICs of bacterial strains by 128- to 256-fold and by 2- to 8-fold Fluconazole MICs against Candida strains.

The antivenom property of the methanolic extract of aerial parts of Adenocarpus anagyrifolius against Hottentotta gentili was evaluated by gavage (100, 150, and 200 mg/kg) after subcutaneous injection of LD99 of H. gentili venom. The results showed a very efficient response with a survival of the mice even after 24 h, while the injection with LD50 and a dose of 200 mg/kg showed a restoration of the lesions in different tissues and a significant decrease of the biochemical markers. The high antioxidant efficiency with the presence of active metabolites may explain the potential of A. anagyrifolius as natural product drug candidate.

The present study aimed to investigate Senecio anteuphorbium, an endemic plant growing in West Morocco and widely used in local folk medicine. The essential oil (EO) extracted from the aerial parts was analyzed by gas chromatography and tested for allelopathic activity. The quantitation of the volatiles was carried out by means of GC-FID with response factors, which were validated through reliable calibration procedures, based on external and internal standardization. This analytical approach allowed to define the real concentration of each constituent (weight%, g/100 g) alongside the conventional relative percent. On the other hand, the identification process was supported by a dual matching based on both mass spectra and retention indices. The essential oil resulted in being rich in sesquiterpenes, with the predominant constituents being bicyclogermacrene (22.75 g/100 g), spathulenol (25.26 g/100 g), epi-γ-eudesmol (6.8 g/100 g), and selina-4,11-diene (5.08 g/100 g). The allelopathic effect was evaluated by studying the inhibition of the germination and growth of Lactuca sativa seeds. A potent allelopathic effect was recorded by the essential oil at a dose of 0.281 mg/mL, with almost a total inhibition of germination.

In the present study, the phytochemical composition and bioactivities of A. maroccanus (AM) and A. radiatus (AR), two ecotypes collected in the Demnate road and Essaouira regions, respectively, were studied to highlight a pharmacological interest and to enable possible pharmaceutical development. To this end, methanolic and ethyl acetate extracts were prepared for each ecotype by fractionation; next, their phytochemical composition was evaluated by spectrophotometric and chromatographic analysis. Moreover, in line with the available evidence for Anacyclus spp. and their traditional use, a screening of bioactivities, including antioxidant, hypoglycemic, antiglycative, chelating, and antibacterial activities, was performed. The extracts were characterized by high amounts of polyphenols, tannins, and flavonoids, especially in the methanolic extracts; these samples were also enriched in carotenoids despite a lower chlorophyll content. Chlorogenic acid and rutin were the major identified compounds. The extracts also showed interesting hypoglycemic, antiglycative, and antibacterial properties, although with differences in efficacy and potency. Present results provide more scientific basis to the ethnopharmacological uses of Anacyclus spp. and suggest a further interest in AM and AR ecotypes as natural sources of bioactive compounds and/or phytocomplexes for possible pharmaceutical and nutraceutical developments.

In this study, the chemical composition, antioxidant potential and antimicrobial interactions with a conventional antibiotic of essential oil (EO) isolated from Andryala pinnatifida subsp. mogadorensis aerial parts were assessed. Twenty eight compounds were identified. Farnesene (14.92%), Decanal (9.51%) and Tetradecanoic acid (7.44%) were the main compounds. The antibacterial potential was evaluated against two bacterial strains identified as resistant to antibiotics: Methicillin-resistant Staphylococcus aureus and Escherichia coli, as well as two sensitive bacterial strains: S. aureus and E. coli. The results obtained reveal that no bacterial strain tested was resistant to the studied EO, with MIC values in the range of (1.56-3.12) mg/mL. However, the combination of the studied EO with gentamicin showed a complete synergism against S. aureus. Furthermore, EO was screened for its antioxidant activity using three methods. IC₅₀ values were 4.34 ± 0.06 mg/mL, 1.16 ± 0.1 mg/mL and 1.94 ± 0.09 mg/mL, respectively, for DPPH, Ferric reducing and β-carotene/linoleic acid assays. The data indicate that the essential oil of this Moroccan endemic plant proved to be an important source of antioxidant and antibacterial products and may be used for the treatment of pathogenic bacteria and could be also implicated in food industries as preservative of foodstuffs.

The essential oil obtained from the aerial parts of Cladanthus arabicus (L.) Cass was studied for its chemical composition, antioxidant, antimicrobial and insecticidal activities. The essential oil (EO) was analyzed by GC-MS. Sixty seven compounds representing 94.2 % of the oil were identified. The major components of C. arabicus EO were sabinene (31.1 %), β-pinene (16.7 %), myrcene (12.3 %) and α-pinene (5.3 %). Moreover, the antioxidant and antimicrobial activities of the essential oil against six bacteria and four Candida strains were studied. The results showed the existence of a strong antioxidant activity with IC₅₀ of 55.4 ± 0.12 μg/mL and 57.2 ± 0.21 μg/mL, respectively for DPPH and FRAP methods. The EO exhibited great antimicrobial activity especially against Micrococcus luteus (MIC = 0.187 mg/mL) and Candida albicans (MIC = 0.187 mg/mL). LD₅₀ and LD₉₀ values were 43.6 and 74.1 ppm against 1d-old larvae of Aedes aegypti, respectively.

Aims: The crude saponins extracted from the aerial parts of Paronychia argentea and the roots of Spergularia marginata were tested for their antioxidant, antimicrobial and synergistic effects with antibiotics. Methodology: Antioxidant activity was evaluated using the 2,2-diphenyl-1-picryl-hydrazyl (DPPH) free radical, β-carotene-linoleic acid and reducing power assays. However, the antibacterial activity was assessed by the agar disc diffusion method, whereas the MIC determination and the synergistic interaction with antibiotics were evaluated using microdilution method. Results: Saponins-rich extract from Paronychia argentea showed a higher antioxidant activity than that from Spergularia marginata. Using DPPH assay, the IC₅₀ values for saponins-rich extracts from P. argentea and S. marginata were 19.08 and 29.65 µg/ml, respectively. For β-carotene-linoleic acid assay, IC₅₀ values were 98.24 and 614 µg/ml respectively for P. argentea and S. marginata. However, for reducing power assays, the IC₅₀ values for saponins-rich extracts from P. argentea and S. marginata were respectively 27.22 and 61.44 µg/ml. The result of MIC assay showed that both saponins-rich extracts was found to be active against the majority of Candida strains and Gram-positive bacteria. However, crude saponins extracted from S. marginata was more active on microorganisms than that from P. argentea. In fact, the in vitro association of saponin extracts and some commercial antibiotics showed a synergistic effect. For bacteria strains, 30 combinations were studied, 17 (56.66%) combinations had total synergism, 7 (23.33%) had partial synergism, 4 (13.33%) had no effect and 2 (6.66%) had antagonism effect. For Candida strains, 8 combinations of saponins extracts and fluconazol are tested. All of these combinations (100%) exhibited a total synergism with FICi ranging from 0,31 to 0,50. Conclusion: The results founded suggested that further work should be performed on the isolation and identification of the antioxidative and antimicrobial components of these saponins-rich extracts.