Seaweed essential oils as a new source of bioactive compounds for cyanobacteria growth control: Innovative ecological biocontrol approach

This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/). The application of natural compounds extracted from seaweeds is a promising eco-friendly alternative solution for harmful algae control in aquatic ecosystems. In the present study, the anti-cyanobacterial activity of three Moroccan marine macroalgae essential oils (EOs) was tested and evaluated on unicellular Microcystis aeruginosa cyanobacterium. Additionally, the possible anti-cyanobacterial response mechanisms were investigated by analyzing the antioxidant enzyme activities of M. aeruginosa cells. The results of EOs GC-MS analyses revealed a complex chemical composition, allowing the identification of 91 constituents. Palmitic acid, palmitoleic acid, and eicosapentaenoic acid were the most predominant compounds in Cystoseira tamariscifolia, Sargassum muticum, and Ulva lactuca EOs, respectively. The highest anti-cyanobacterial activity was recorded for Cystoseira tamariscifolia EO (ZI = 46.33 mm, MIC = 7.81 µg mL−1, and MBC = 15.62 µg mL−1). The growth, chlorophyll-a and protein content of the tested cyanobacteria were significantly reduced by C. tamariscifolia EO at both used concentrations (inhibition rate >67% during the 6 days test period in liquid media). Furthermore, oxidative stress caused by C. tamariscifolia EO on cyanobacterium cells showed an increase of the activities of superoxide dismutase (SOD) and catalase (CAT), and malondialdehyde (MDA) concentration was significantly elevated after 2 days of exposure. Overall, these experimental findings can open a promising new natural pathway based on the use of seaweed essential oils to the fight against potent toxic harmful cyanobacterial blooms (HCBs).This project received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 823860; Foundation for Science and Technology (FCT, Portugal) for financial support through national funds FCT/MCTES to UIDB/04423/2020, UIDP/04423/2020 and UIDB/00690/2020 (CIMO), and also FCT, P.I., through the institutional scientific employment program-contract for L. Barros contract.info:eu-repo/semantics/publishedVersio

Geochemistry and Sm–Nd isotopic composition of the Imiter Pan-African granitoids (Saghro massif, eastern Anti-Atlas, Morocco): Geotectonic implications

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Synergistic Anticandidal Effects of Six Essential Oils in Combination with Fluconazole or Amphotericin B against Four Clinically Isolated Candida Strains

The development of opportunistic pathogenic Candida strains insensitive to several classes of antifungals has emerged as a major health care problem during the last years. Combinational therapy of natural products (e.g., essential oils, EOs) with conventional antifungals has been suggested as a promising alternative to overcome this medical problem. The present study investigates the potential antifungal activity of EOs extracted from some selected medicinal plants, alone and in combination with two common conventional antifungals (fluconazole and amphotericin B) against four clinical Candida isolates. MIC assays indicated that EOs induced strong anticandidal activities with MIC values ranging from 0.162 to 4.950 mg/mL. The combination of amphotericin B with Thymus leptobotrys, Origanum compactum and Artemisia herba alba EOs provided a synergistic effect against C. krusei only, with MIC gain of four-fold, and additive effect against remaining strains (MIC gain = two-fold). Interesting synergistic interactions were observed by combining all studied EOs with fluconazole, with reduction rates of their MICs ranging from 16 to 512-fold. This synergistic effect was very pronounced with the combination of T. leptobotrys EO and fluconazole. These findings indicate that studied EOs can be used as anti-candidals in combination with antifungals, particularly fluconazole, to counteract the emergence of resistant Candida spp

Antihyperlipidemic effect and GC-MS analysis of phytoconstituents from <i>Laurus nobilis</i> essential oil in rat

This study aimed to evaluate the effect of Laurus nobilis (L. nobilis) essential oil (EOs) (80 mg/kg) on Triton WR-1339-induced dyslipidemia in Wistar rats. The effect of L. nobilis essential oil (80 mg/kg) on lipid and lipoprotein profile was examined on Triton WR-1339-induced dyslipidemia in rats. Furthermore, the phytochemical evaluation was performed by GC-MS. In Addition, the acute toxicity of this EO was evaluated at a dose of 2 g/kg. The results revealed that the main constituents of L. nobilis EO were 1,8-cineole (39.5%), linalool (13.09%), and a-terpineol (11.55%). Furthermore, the EO did not cause any signs of toxicity or mortality, and the acute lethal dose 50 (LD50) was estimated to be higher than 2 g/kg. L. nobilis EO ameliorated lipid parameters and atherogenic indices. In conclusion, the study demonstrates that L. nobilis essential oils possess antidyslipidemic activity in acute model of hyperlipidaemia.</p

SHRIMP U–Pb zircon geochronology of the granitoids of the Imiter Inlier: Constraints on the Pan-African events in the Saghro massif, Anti-Atlas (Morocco)

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Optimization of the insecticidal response of combined essential oils from Satureja alpina, Rosmarinus officinalis and Ammodaucus leucotrichus using a designed mixtures approach

The main objective of the present study is to investigate the fumigant toxicity of EOs extracted from Satureja alpina (L.) Scheele (Lamiaceae), Rosmarinus officinalis (L.) (Lamiaceae) and Ammodaucus leucotrichus(Coss. &amp; Durieu) (Apiaceae) and to predict specific EO mixtures that provide optimal insecticidal activities against two common secondary insect pests, namely Stegobium paniceum (L.) (Coleoptera: Anobiidae) and Tribolium confusum du Val (Coleoptera: Tenebrionidae). GC/MS analysis showed that A. leucotrichus EO was characterized by the abundance of L-perillaldehyde and D-limonene, while the main constituents of R. officinalis EO were 1.8-cineole, camphor, and α-pinene. S. alpina EO was mainly composed of pulegone. Concerning the insecticidal activity, the results showed that all EOs tested individually exerted high efficacy, with LC50 from 3.4 to 6.6 µL/L air for S. paniceum, and from 25.3 to 41.9 µL/L air for T. confusum. The various combinations of these EOs were generally found to possess greater activity than when used individually, and synergistic interactions were recorded. The optimal mixtures predicted were 48% S. alpina, 31% R. officinalis and 21% A. leucotrichus EOs, corresponding to LC50 of 1.47 µL/L air; and 57% A. leucotrichus and 43% S. alpina EOs corresponding to LC50 of 8.26 µL/L air, for S.paniceum and T. confusum, respectively. Our findings showed that the use of these optimized EO combinations from the tested plants could be a promising insecticidal alternative to reduce the use of harmful synthetic insecticides