Research

14 pages, 1435 KiB

Open AccessArticle

Synergistic Effect of Bioactive Monoterpenes against the Mosquito, Culex pipiens (Diptera: Culicidae)

by Amal Ramzi, Abdelhakim El Ouali Lalami, Saoussan Annemer, Yassine Ez zoubi, Amine Assouguem, Mikhlid H. Almutairi, Mohamed Kamel, Ilaria Peluso, Sezai Ercisli and Abdellah Farah

Molecules 2022, 27(13), 4182; https://doi.org/10.3390/molecules27134182 - 29 Jun 2022

Cited by 4 | Viewed by 1416

Abstract

Mosquitoes represent one of the most important vectors and are responsible for the transmission of many arboviruses that affect human and animal health. The chemical method using synthetic insecticides disturbs the environmental system and promotes the appearance of resistant insect species. Therefore, this [...] Read more.

Mosquitoes represent one of the most important vectors and are responsible for the transmission of many arboviruses that affect human and animal health. The chemical method using synthetic insecticides disturbs the environmental system and promotes the appearance of resistant insect species. Therefore, this study investigated the insecticidal effect of some binary monoterpene combinations (1,8 cineole + α-pinene and carvone + R (+)-pulegone) using a mixture design approach. The fumigant toxicity was evaluated against Culex pipiens female adults using glass jars. The results show that the toxicity varies according to the proportions of each compound. Indeed, Mixture 1 (1,8-cineole + α-pinene) displayed a strong toxic effect (51.00 ± 0.86% after 24 h and 100.00 ± 0.70% after 48 h) when the pure compounds were tested at 0.25/0.75 proportions of 1,8-cineole and α-pinene, respectively. Nevertheless, the equal proportion (0.5/0.5) of carvone and R (+)-pulegone in Mixture 2 exhibited a toxic effect of 54.35 ± 0.75% after 24 h and 89.96 ± 0.14% after 48 h, respectively. For Mixture 1, the maximum area of mortality that the proposed model indicated was obtained between 0/1 and 0.25/0.75, while the maximum area of mortality in the case of Mixture 2 was obtained between 0.25/0.75 and 0.75/0.25. Moreover, the maximum possible values of mortality that could be achieved by the validated model were found to be 51.44% (after 24 h) and 100.24% (after 48 h) for Mixture 1 and 54.67% (after 24 h) and 89.99% (after 48 h) for Mixture 2. It can be said that all purev molecules tested through the binary mixtures acted together, which enhanced the insecticide’s effectiveness. These findings are very promising, as the chemical insecticide (deltamethrin) killed only 19.29 ± 0.01% and 34.05 ± 1.01% of the female adults after 24 h and 48 h, respectively. Thus, the findings of our research could help with the development of botanical insecticides that might contribute to management programs for controlling vectors of important diseases. Full article

(This article belongs to the Special Issue Essential Oils: Biological Activities and New Possible Applications)

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21 pages, 6337 KiB

Open AccessArticle

Bio-Herbicidal Potential of Nanoemulsions with Peppermint Oil on Barnyard Grass and Maize

by Magdalena Rys, Małgorzata Miastkowska, Elżbieta Sikora, Anna Łętocha, Agnieszka Krajewska and Agnieszka Synowiec

Molecules 2022, 27(11), 3480; https://doi.org/10.3390/molecules27113480 - 28 May 2022

Cited by 6 | Viewed by 2063

Abstract

Bio-based nanoemulsions are part of green pest management for sustainable agriculture. This study assessed the physicochemical properties and the herbicidal activities of the peppermint essential oil nanoemulsions (PNs) in concentrations 1.0–10% stabilized by Eco-Polysorbate 80 on germinating seeds and young plants of maize [...] Read more.

Bio-based nanoemulsions are part of green pest management for sustainable agriculture. This study assessed the physicochemical properties and the herbicidal activities of the peppermint essential oil nanoemulsions (PNs) in concentrations 1.0–10% stabilized by Eco-Polysorbate 80 on germinating seeds and young plants of maize and barnyard grass. Based on the design of experiment (DOE) results, the final nanoemulsion formulations were obtained with 1, 1.5, 2, and 5% of essential oil concentration. Biological analyses were conducted to select the most promising sample for selective control of barnyard grass in maize. Seedlings growing in the presence of PNs displayed an overall inhibition of metabolism, as expressed by the calorimetric analyses, which could result from significant differences in both content and composition of carbohydrates. Concentration–response sub estimation showed that leaf-sprayed concentration of PN causing 10% of maize damage is equal to 2.2%, whereas doses causing 50% and 90% of barnyard grass damage are 1.1% and 1.7%, respectively. Plants sprayed with PN at 5% or 10% concentration caused significant drops in relative water content in leaves and Chlorophyll a fluorescence 72 h after spraying. In summary, peppermint nanoemulsion with Eco-Polysorbate 80 at 2% concentration is a perspective preparation for selective control of barnyard grass in maize. It should be analyzed further in controlled and field conditions. Full article

(This article belongs to the Special Issue Essential Oils: Biological Activities and New Possible Applications)

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15 pages, 2068 KiB

Open AccessArticle

Evaluation of Antibacterial and Antifungal Effects of Calcium Hydroxide Mixed with Two Different Essential Oils

by Gokalp Cosan, Cenk Serhan Ozverel, Duygu Yigit Hanoglu, Kemal Husnu Can Baser and Yasar Meric Tunca

Molecules 2022, 27(9), 2635; https://doi.org/10.3390/molecules27092635 - 20 Apr 2022

Cited by 3 | Viewed by 3041

Abstract

Background: Calcium hydroxide is a routinely used material for root canal disinfection during root canal treatment. Natural products have great potential in terms of their antibacterial effects. This study aimed to establish an effective alternative intracanal medicament using Origanum dubium (O. dubium) and [...] Read more.

Background: Calcium hydroxide is a routinely used material for root canal disinfection during root canal treatment. Natural products have great potential in terms of their antibacterial effects. This study aimed to establish an effective alternative intracanal medicament using Origanum dubium (O. dubium) and Mentha spicata (M. spicata) essential oils. Materials and Methods: O. dubium and M. spicata, collected from Lefke, Cyprus, were separately subjected to hydrodistillation. The obtained essential oil compositions were analysed simultaneously by gas chromatography (GC) and gas chromatography/mass spectrometry (GC-MS). The compositions were then divided into groups and mixed with calcium hydroxide at a 1:1 concentration; after that, the pastes were tested on Enterococcus faecalis (E. faecalis) and Candida albicans (C. albicans), which are the most common resistant pathogenic microorganisms in the root canal. The antibacterial activity of the pastes was measured using a disk diffusion assay. Results: The GC and GC-MS analyses revealed that O. dubium and M. spicata had major compositions of carvacrol (75.8%) and carvone (71.3%), respectively. Antimicrobial activity was found to be significantly higher when study groups with O. dubium essential oil were applied to both E. faecalis and C. albicans. The results also show that M. spicata, together with calcium hydroxide, demonstrated a significant antifungal effect on C. albicans when incubated for 72 h. Conclusions: M. spicata was found to be an effective antimicrobial agent on C. albicans, whereas O. dubium was found to be very effective on both E. faecalis and C. albicans. These data demonstrate that these natural essential oils may be promising candidates for alternative intracanal medicament in future routine clinical applications. Full article

(This article belongs to the Special Issue Essential Oils: Biological Activities and New Possible Applications)

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15 pages, 680 KiB

Open AccessArticle

Anti-Biofilms’ Activity of Garlic and Thyme Essential Oils against Salmonella typhimurium

by Alaa Eldin M. A. Morshdy, Ahmed S. El-tahlawy, Sameer H. Qari, Alaa T. Qumsani, Daniyah Habiballah Bay, Rokayya Sami, Eman Hillal Althubaiti, Ahmed M. A. Mansour, Amani H. Aljahani, Abd El-Salam E. Hafez, Abdallah Fikry A. Mahmoud, Rasha M. El Bayomi and Mohamed A. Hussein

Molecules 2022, 27(7), 2182; https://doi.org/10.3390/molecules27072182 - 28 Mar 2022

Cited by 17 | Viewed by 2832

Abstract

Biofilm control by essential oil (EO) application has recently increased to preclude biofilm production on foods and environmental surfaces. In this work, the anti-biofilm effects of garlic and thyme essential oils using the minimum inhibitory concentration (MIC) method against Salmonella typhimurium recovered from [...] Read more.

Biofilm control by essential oil (EO) application has recently increased to preclude biofilm production on foods and environmental surfaces. In this work, the anti-biofilm effects of garlic and thyme essential oils using the minimum inhibitory concentration (MIC) method against Salmonella typhimurium recovered from different abattoir samples were investigated along with the virulence genes (InvA, SdiA and Stn genes), and the antimicrobial susceptibility profile of S. typhimurium as well. The obtained results revealed that S. typhimurium contaminated abattoir samples to varying degrees. The InvA gene was investigated in all isolates, whereas the SdiA and Stn genes were observed in four and three isolates, respectively. Utilizing the disc diffusion method, S. typhimurium isolates demonstrated substantial resistance to most of the examined antibiotics with a high multiple antibiotic resistance index. S. typhimurium isolates demonstrated biofilm formation abilities to various degrees at varied temperatures levels (4 °C and 37 °C). In conclusion, the obtained samples from the research area are regarded as a potential S. typhimurium contamination source. Furthermore, garlic essential oil (GEO) has more potential to inhibit S. typhimurium biofilm at different sub-minimum inhibitory concentrations as compared to thyme essential oil (TEO). Therefore, these EOs are considered as potential natural antibacterial options that could be applied in food industry. Full article

(This article belongs to the Special Issue Essential Oils: Biological Activities and New Possible Applications)

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9 pages, 666 KiB

Open AccessArticle

Antimicrobial and Larvicidal Activities of Different Ocimum Essential Oils Extracted by Ultrasound-Assisted Hydrodistillation

by Kuzhimbattil Sneha, Arunaksharan Narayanankutty, Joice Tom Job, Opeyemi Joshua Olatunji, Ahmed Alfarhan, Ademola C. Famurewa and Varsha Ramesh

Molecules 2022, 27(5), 1456; https://doi.org/10.3390/molecules27051456 - 22 Feb 2022

Cited by 12 | Viewed by 2326

Abstract

Infectious diseases and their vectors have remained a concern for human population from their historical origin. Microbial pathogens have also emerged as a potent threat to the healthcare systems even in developed countries. Essential oils remain a less explored method for infectious disease [...] Read more.

Infectious diseases and their vectors have remained a concern for human population from their historical origin. Microbial pathogens have also emerged as a potent threat to the healthcare systems even in developed countries. Essential oils remain a less explored method for infectious disease control; besides, the ultrasound-assisted extraction (UAE) of essential oil production has emerged as promising source of bioactive volatiles over conventional methods. This study analyzed the possible use of UAE- Essential oils (EOs) from different species of Ocimum plants (Ocimum basilicum (OB), O. gratissimum (OG), O. tenuiflorum (OT), and O. canum (OC)) in the management of microbial pathogens and mosquito larval control. The antibacterial activity was estimated in terms of a disc diffusion assay and minimum inhibitory concentrations against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Salmonella enteritidis. The larvicidal property was found using three important mosquito vectors and the LC₅₀ value was determined. Furthermore, antioxidant and anti-inflammatory properties were estimated in terms of radical scavenging activities and the inhibition of lipoxygenase enzyme activity. The EOs exhibited significant DPPH radical scavenging (high in OG), hydrogen-peroxide scavenging (OB) and lipoxygenase inhibition (OB). The antibacterial activity was high in OB and OG (p < 0.05) and the larvicidal activity was of higher sensitivity against Aedis and Culex, whereas Armigeres was more resistant. However, no sign of toxicity in the Allium cepa model or non-targeted organism Guppy fishes was observed. Overall, the UAE extracted Ocimum essential oils were found to be effective against various human pathogenic microbial organisms, with OB and OG being highly active. Likewise, the EOs was also able to induce mortality in the larval forms of various mosquito vectors. Full article

(This article belongs to the Special Issue Essential Oils: Biological Activities and New Possible Applications)

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17 pages, 11771 KiB

Open AccessArticle

Performance of Thyme Oil@Na-Montmorillonite and Thyme Oil@Organo-Modified Montmorillonite Nanostructures on the Development of Melt-Extruded Poly-L-lactic Acid Antioxidant Active Packaging Films

by Aris E. Giannakas, Constantinos E. Salmas, Areti Leontiou, Dimitrios Moschovas, Maria Baikousi, Eleni Kollia, Vasiliki Tsigkou, Anastasios Karakassides, Apostolos Avgeropoulos and Charalampos Proestos

Molecules 2022, 27(4), 1231; https://doi.org/10.3390/molecules27041231 - 11 Feb 2022

Cited by 8 | Viewed by 2097

Abstract

Today, the use of natural biodegradable materials in the production processes is more and more adopted by industry to achieve cyclic economy targets and to improve environmental and human health indexes. Active packaging is the latest trend for food preservation. In this work, [...] Read more.

Today, the use of natural biodegradable materials in the production processes is more and more adopted by industry to achieve cyclic economy targets and to improve environmental and human health indexes. Active packaging is the latest trend for food preservation. In this work, nanostructures were prepared by incorporation of thyme oil with natural natrium-montmorillonite and organo-montmorillonite with two different techniques, direct impregnation and the green evaporation–adsorption process. Such nanostructures were mixed with poly-L-lactic-acid for the first time via an extrusion molding process to develop a new packaging film. Comparisons of morphological, mechanical, and other basic properties for food packaging were carried out via XRD, FTIR, TG, SEM/EDS, oxygen and water vapor permeation, and antimicrobial and antioxidant activity for the first time. Results showed that poly-L-lactic-acid could be modified with clays and essential oils to produce improved active packaging films. The final product exhibits food odor prevention characteristics and shelf-life extension capabilities, and it could be used for active packaging. The films based on OrgMt clay seems to be more promising, while the thyme oil addition improves their behavior as active packaging. The PLLA/3%TO@OrgMt and PLLA/5%TO@OrgMt films were qualified between the tested samples as the most promising materials for this purpose. Full article

(This article belongs to the Special Issue Essential Oils: Biological Activities and New Possible Applications)

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10 pages, 495 KiB

Open AccessArticle

Chemical Composition, Insecticidal and Mosquito Larvicidal Activities of Allspice (Pimenta dioica) Essential Oil

by Arunaksharan Narayanankutty, Aswathi Moothakoottil Kuttithodi, Ahmed Alfarhan, Rajakrishnan Rajagopal and Damia Barcelo

Molecules 2021, 26(21), 6698; https://doi.org/10.3390/molecules26216698 - 05 Nov 2021

Cited by 12 | Viewed by 2457

Abstract

Essential oils are biologically and environmentally safe pesticidal compounds yielded from aromatic plants. Spices are important sources of essential oils, and they are widely used in the medicine, food, and various other industries. Among the different spices, Allspice (Pimenta dioica) is [...] Read more.

Essential oils are biologically and environmentally safe pesticidal compounds yielded from aromatic plants. Spices are important sources of essential oils, and they are widely used in the medicine, food, and various other industries. Among the different spices, Allspice (Pimenta dioica) is underexplored in terms of its biological efficacy and a limited number of studies are available on the chemical composition of Allspice essential oil (AEO); thus, the present study evaluated the larvicidal property, the repellency, and the fumigant toxicity against common pests of stored products of AEO. AEO was found to inhibit the survival of larvae of such vectors as Aedis, Culex, and Armigeres species. Further, AEO was found to exert repellant effects against the pests of such stored products as Sitophilus, Callosobruchus, and Tribolium. Similarly, the fumigant toxicity was found to be high for AEO against these species. The contact toxicity of AEO was high against Sitophilus and Callosobruchus. Apart from that, the essential oil was found to be safe against a non-target organism (guppy fishes) and was found to be non-genotoxic in an Allium cepa model. Overall, the results of the present study indicate that the essential oil from Allspice could be used as an environmentally safe larvicidal and biopesticidal compound. Full article

(This article belongs to the Special Issue Essential Oils: Biological Activities and New Possible Applications)

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9 pages, 561 KiB

Open AccessArticle

Chemical Composition of Cinnamomum verum Leaf and Flower Essential Oils and Analysis of Their Antibacterial, Insecticidal, and Larvicidal Properties

by Arunaksharan Narayanankutty, Krishnaprasad Kunnath, Ahmed Alfarhan, Rajakrishnan Rajagopal and Varsha Ramesh

Molecules 2021, 26(20), 6303; https://doi.org/10.3390/molecules26206303 - 19 Oct 2021

Cited by 20 | Viewed by 3127

Abstract

Cinnamomum verum is widely used in traditional medicines, and the different parts of the plant, such as bark, leaves, and flowers, are used for essential oil production. The present study compared the chemical composition of the essential oil of C. verum extracted from [...] Read more.

Cinnamomum verum is widely used in traditional medicines, and the different parts of the plant, such as bark, leaves, and flowers, are used for essential oil production. The present study compared the chemical composition of the essential oil of C. verum extracted from the leaves and flowers. In addition, efficacy of these essential oils against the two common pests Sitophilus oryzae and Callosobruchus maculatus was also evaluated. The results indicated the presence of cinnamaldehyde, eugenol, caryophyllene, and linalool in these essential oils, however, at different concentrations. The leaf essential oil was found to be 10–20% more effective as a fumigant against both the pests. Likewise, the leaf essential oil found to repel these pests even at lower concentrations than that of flower essential oil of C. verum. Besides, these essential oils were also effective in controlling the growth of various gram positive and gram negative microbial pathogens and possibly a safeguard for human health. On contrary, both the essential oils were found to be safe for the application on grains, as indicated by their germination potentials. It was also observed that these essential oils do not cause any significant toxicity to guppy fishes, thus confirming their ecological safety for use as a biopesticide. Full article

(This article belongs to the Special Issue Essential Oils: Biological Activities and New Possible Applications)

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18 pages, 2307 KiB

Open AccessArticle

Chemical Composition, Antipathogenic and Cytotoxic Activity of the Essential Oil Extracted from Amorpha fruticosa Fruits

by Ioana Cristina Marinas, Eliza Oprea, Mihaela Buleandra, Irinel Adriana Badea, Bianca Maria Tihauan, Luminita Marutescu, Marin Angheloiu, Elena Matei and Mariana Carmen Chifiriuc

Molecules 2021, 26(11), 3146; https://doi.org/10.3390/molecules26113146 - 24 May 2021

Cited by 13 | Viewed by 2590

Abstract

The purpose of this paper was to characterize and investigate the antimicrobial potential of Amorpha fruticosa fruits essential oil (EO). The EO was extracted by hydrodistillation, analyzed by GC-MS, and then evaluated for its interaction with microbial and mammalian cells. The antimicrobial activity [...] Read more.

The purpose of this paper was to characterize and investigate the antimicrobial potential of Amorpha fruticosa fruits essential oil (EO). The EO was extracted by hydrodistillation, analyzed by GC-MS, and then evaluated for its interaction with microbial and mammalian cells. The antimicrobial activity was assessed against bacterial and fungal strains, in a planktonic and adherent growth state, using qualitative and quantitative assays. The main components identified in A. fruticosa fruits EO were δ-cadinene, γ-muurolene, and α-muurolene. The Gram-positive strains proved to be more susceptible than Gram-negative bacteria and fungal strains. The EO exhibited good antibiofilm activity, inhibiting the microbial adherence to the inert (96-well plates and Foley catheter section) and cellular substrata. The flow cytometry analysis revealed as one of the possible mechanisms of antimicrobial action the alteration of cell membrane hydrophobicity. The cytotoxicity on the L929 cell line occurred at concentrations higher than 0.3 mg/mL. Taken together, our results demonstrate that A. fruticosa fruits EO contains active compounds with selective inhibitory effect on different microbial strains in planktonic and biofilm growth state, explained at least partially by the interference with microbial membranes due to their hydrophobic character. Full article

(This article belongs to the Special Issue Essential Oils: Biological Activities and New Possible Applications)

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14 pages, 2255 KiB

Open AccessArticle

Protective Effects of Cinnamaldehyde on the Inflammatory Response, Oxidative Stress, and Apoptosis in Liver of Salmonella typhimurium-Challenged Mice

by Renjie Wang, Senlin Li, Hai Jia, Xuemeng Si, Yan Lei, Jirong Lyu, Zhaolai Dai and Zhenlong Wu

Molecules 2021, 26(8), 2309; https://doi.org/10.3390/molecules26082309 - 16 Apr 2021

Cited by 32 | Viewed by 3262

Abstract

Salmonella typhimurium infection is associated with gastrointestinal disorder and cellular injury in the liver of both humans and animals. Cinnamaldehyde, the main component of essential oil from cinnamon, has been reported to have anti-inflammatory, anti-oxidative, and anti-apoptotic effects. However, it remains unknown whether [...] Read more.

Salmonella typhimurium infection is associated with gastrointestinal disorder and cellular injury in the liver of both humans and animals. Cinnamaldehyde, the main component of essential oil from cinnamon, has been reported to have anti-inflammatory, anti-oxidative, and anti-apoptotic effects. However, it remains unknown whether cinnamaldehyde can alleviate Salmonella typhimurium infection-induced liver injury in mice. In the present study, we found that cinnamaldehyde attenuated Salmonella typhimurium-induced body weight loss, the increase of organ (liver and spleen) indexes, hepatocyte apoptosis, and the mortality rate in mice. Further study showed that cinnamaldehyde significantly alleviated Salmonella typhimurium-induced liver injury as shown by activities of alanine transaminase, aspartate transaminase, and myeloperoxidase, as well as malondialdehyde. The increased mRNA level of pro-inflammatory cytokines (IL-1β, IL-6, TNF-α, and IFN-γ) and chemokines (CCL2 and CCL3) induced by Salmonella typhimurium were significantly abolished by cinnamaldehyde supplementation. These alterations were associated with a regulatory effect of cinnamaldehyde on TLR2, TLR4, and MyD88. 16S rDNA sequence analysis showed that Salmonella typhimurium infection led to upregulation of the abundances of genera Akkermansia, Bacteroides, Alistipes, Muribaculum, and Prevotellaceae UCG-001, and downregulation of the abundances of genera Lactobacillus, Enterorhabdus, and Eggerthellaceae (unclassified). These alterations were reversed by cinnamaldehyde supplementation. In conclusion, cinnamaldehyde attenuated the inflammatory response, oxidative stress, and apoptosis in the liver of Salmonella typhimurium-infected mice. Supplementation of cinnamaldehyde might be a preventive strategy to alleviate liver injury caused by Salmonella typhimurium infection in humans and animals. Full article

(This article belongs to the Special Issue Essential Oils: Biological Activities and New Possible Applications)

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