Editorial

3 pages, 190 KiB

Open AccessEditorial

Special Issue: Isolation and Utilization of Essential Oils: As Antimicrobials and Boosters of Antimicrobial Drug Activity

by Elwira Sieniawska, Adriana Trifan and Hélène Greige-Gerges

Processes 2022, 10(2), 309; https://doi.org/10.3390/pr10020309 - 04 Feb 2022

Viewed by 1001

Abstract

In the search for new antimicrobial lead compounds, interest in natural-product-based screening has enjoyed a renaissance, driven by the fact that plants present a unique pool of compounds [...] Full article

(This article belongs to the Special Issue Isolation and Utilization of Essential Oils: As Antimicrobials and Boosters of Antimicrobial Drug Activity)

Research

Jump to: Editorial, Review

13 pages, 2425 KiB

Open AccessArticle

Croton cajucara Essential Oil Nanoemulsion and Its Antifungal Activities

by Mariana M. B. Azevedo, Catia A. Almeida, Francisco C. M. Chaves, Eduardo Ricci-Júnior, Andreza R. Garcia, Igor A. Rodrigues, Celuta S. Alviano and Daniela S. Alviano

Processes 2021, 9(11), 1872; https://doi.org/10.3390/pr9111872 - 21 Oct 2021

Cited by 7 | Viewed by 2066

Abstract

The purpose of this study was to develop a stable nanoemulsion (NE) containing Croton cajucara 7-hydroxycalamenene-rich essential oil (NECC) with antifungal activity. The NECCs were prepared using an ultrasonic processor with Pluronic^® F-127 as the aqueous phase. In order to evaluate the [...] Read more.

The purpose of this study was to develop a stable nanoemulsion (NE) containing Croton cajucara 7-hydroxycalamenene-rich essential oil (NECC) with antifungal activity. The NECCs were prepared using an ultrasonic processor with Pluronic^® F-127 as the aqueous phase. In order to evaluate the NECCs, the droplet size, polydispersity index (PdI), percentage of emulsification, and pH were determined along with a stability study. The NECC selected for the study had 15% surfactant, showed 100% emulsification, Pdl of 0.249, neutral pH, droplet diameters of about 40 nm, and remained stable over 150 days at room temperature. In addition, the NECC activity against some species of Zygomycetes and Candida, as well as the potential to inhibit fungal extracellular proteases, were assessed, and, finally, the hemolytic activity was evaluated. The best NECC antifungal activities were against Mucorramosissimus (Minimal inhibitory concentration (MIC) = 12.2 μg/mL) and Candida albicans (MIC = 25.6 μg/mL). The highest extracellular protease activities of M. ramosissimus and C. albicans were detected at pH 3 and 4, respectively, which were totally inhibited after NECC treatment. The NECC showed no hemolytic effect at the highest concentration tested (2 mg/mL). Full article

(This article belongs to the Special Issue Isolation and Utilization of Essential Oils: As Antimicrobials and Boosters of Antimicrobial Drug Activity)

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11 pages, 272 KiB

Open AccessArticle

Volatiles from Selected Apiaceae Species Cultivated in Poland—Antimicrobial Activities

by Jaroslaw Widelski, Konstantia Graikou, Christos Ganos, Krystyna Skalicka-Wozniak and Ioanna Chinou

Processes 2021, 9(4), 695; https://doi.org/10.3390/pr9040695 - 15 Apr 2021

Cited by 13 | Viewed by 1810

Abstract

As part of our ongoing research on phytoconstituents that can act as promising antimicrobial agents, the essential oils of nine selected Apiaceae plants, cultivated in Poland, were studied. The volatiles of the aerial parts with fruits (herba cum fructi) of Silaum [...] Read more.

As part of our ongoing research on phytoconstituents that can act as promising antimicrobial agents, the essential oils of nine selected Apiaceae plants, cultivated in Poland, were studied. The volatiles of the aerial parts with fruits (herba cum fructi) of Silaum silaus, Seseli devenyense, Seseli libanotis,Ferula assa-foetida, Glehnia littoralis and Heracleum dulce, in addition to the fruits (fructi) of Torilis japonica and Orlaya grandiflora as well as of the aerial parts (herba) of Peucedanum luxurians were investigated through Gas Chromatography–Mass Spectrometry to identify more than 60 different metabolites. The essential oils from S. devenyense, H. dulce, T. japonica and P. luxurians are reported for the first time. All examined species were also assayed for their antimicrobial activities against several human pathogenic Gram-positive and -negative bacteria and fungi. The species H. dulce, S. devenyense and S. libanotis exerted the strongest antimicrobial activity, mostly against Gram-positive bacteria strains (MIC values 0.90–1.20 mg/mL). To the best of our knowledge, this is the first attempt to determine the antimicrobial activity of the above Apiaceae species. Full article

(This article belongs to the Special Issue Isolation and Utilization of Essential Oils: As Antimicrobials and Boosters of Antimicrobial Drug Activity)

20 pages, 1775 KiB

Open AccessArticle

Chemical Profiling of Pistacia lentiscus var. Chia Resin and Essential Oil: Ageing Markers and Antimicrobial Activity

by Vasiliki K. Pachi, Eleni V. Mikropoulou, Sofia Dimou, Mariangela Dionysopoulou, Aikaterini Argyropoulou, George Diallinas and Maria Halabalaki

Processes 2021, 9(3), 418; https://doi.org/10.3390/pr9030418 - 25 Feb 2021

Cited by 17 | Viewed by 3552

Abstract

Chios Mastic Gum (CMG) and Chios Mastic Oil (CMO) are two unique products of the tree Pistacia lentiscus var. Chia, cultivated exclusively on the Greek island of Chios. In the present study, the method proposed by the European Pharmacopoeia for mastic identification [...] Read more.

Chios Mastic Gum (CMG) and Chios Mastic Oil (CMO) are two unique products of the tree Pistacia lentiscus var. Chia, cultivated exclusively on the Greek island of Chios. In the present study, the method proposed by the European Pharmacopoeia for mastic identification was employed using HPTLC together with an in-house method. A GC-MS methodology was also developed for the chemical characterization of CMOs. α-Pinene and β-myrcene were found in abundance in the fresh oils; however, in the oil of the aged collection, oxygenated monoterpenes and benzenoids such as verbenone, pinocarveol, and α-campholenal were found at the highest rates. Additionally, the antimicrobial activity of Chios Mastic Gums (CMGs) with their respective Chios Mastic Oils (CMOs) was evaluated, with growth tests against the fungi Aspergillus nidulans, Aspergillus fumigatus, Candida albicans, Mucor circinelloides, and Rhizopus oryzae, and the bacteria Escherichia coli, Pseudomonas aeruginosa and Bacillus subtilis, with the samples exhibiting a moderate activity. To our knowledge, this is the first time that an HPTLC method is proposed for the analysis of mastic and its essential oil and that a standardized methodology is followed for the distillation of CMO with a parallel assessment of the ageing effect on the oil’s composition. Full article

(This article belongs to the Special Issue Isolation and Utilization of Essential Oils: As Antimicrobials and Boosters of Antimicrobial Drug Activity)

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17 pages, 5718 KiB

Open AccessFeature PaperArticle

Biofilm Degradation of Nontuberculous Mycobacteria Formed on Stainless Steel Following Treatment with Immortelle (Helichrysum italicum) and Common Juniper (Juniperus communis) Essential Oils

by Dolores Peruč, Dalibor Broznić, Željka Maglica, Zvonimir Marijanović, Ljerka Karleuša and Ivana Gobin

Processes 2021, 9(2), 362; https://doi.org/10.3390/pr9020362 - 16 Feb 2021

Cited by 4 | Viewed by 2388

Abstract

Nontuberculous mycobacteria, like other opportunistic premise plumbing pathogens, produce resistant biofilms on various surfaces in the plumbing system including pipes, tanks, and fittings. Since standard methods of water disinfection are ineffective in eradicating biofilms, research into new agents is necessary. Essential oils (EOs) [...] Read more.

Nontuberculous mycobacteria, like other opportunistic premise plumbing pathogens, produce resistant biofilms on various surfaces in the plumbing system including pipes, tanks, and fittings. Since standard methods of water disinfection are ineffective in eradicating biofilms, research into new agents is necessary. Essential oils (EOs) have great potential as anti-biofilm agents. Therefore, the purpose of this research was to investigate the potential anti-biofilm effect of common juniper (Juniperus communis) and immortelle (Helichrysum italicum) EOs. Minimum inhibitory concentrations (MIC), minimum bactericidal concentrations (MBC), and minimum effective concentrations of EOs on Mycobacterium avium, M. intracellulare, and M. gordonae were tested. Additionally, biofilms on the surface of a stainless steel disc were treated with single or mixed concentration of EOs, in order to investigate their degeneration via the bacterial count and confocal laser scanning microscopy (CLSM). H. italicum EO showed the strongest biofilm degradation ability against all Mycobacteria strains that were tested. The strongest effect in the biofilm degradation after the single or mixed applications of EOs was observed against M. gordonae, followed by M. avium. The most resistant was the M. intracellulare biofilm. Synergistic combinations of J. communis and H. italicum EOs therefore seem to be an effective substance in biofilm degradation for use in small water systems such as baths or hot tubs. Full article

(This article belongs to the Special Issue Isolation and Utilization of Essential Oils: As Antimicrobials and Boosters of Antimicrobial Drug Activity)

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Review

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17 pages, 368 KiB

Open AccessReview

Combination Therapy Involving Lavandula angustifolia and Its Derivatives in Exhibiting Antimicrobial Properties and Combatting Antimicrobial Resistance: Current Challenges and Future Prospects

by Wye-Hong Leong, Kok-Song Lai and Swee-Hua Erin Lim

Processes 2021, 9(4), 609; https://doi.org/10.3390/pr9040609 - 30 Mar 2021

Cited by 12 | Viewed by 2846

Abstract

Antimicrobial resistance (AMR) has been identified as one of the biggest health threats in the world. Current therapeutic options for common infections are markedly limited due to the emergence of multidrug resistant pathogens in the community and the hospitals. The role of different [...] Read more.

Antimicrobial resistance (AMR) has been identified as one of the biggest health threats in the world. Current therapeutic options for common infections are markedly limited due to the emergence of multidrug resistant pathogens in the community and the hospitals. The role of different essential oils (EOs) and their derivatives in exhibiting antimicrobial properties has been widely elucidated with their respective mechanisms of action. Recently, there has been a heightened emphasis on lavender essential oil (LEO)’s antimicrobial properties and wound healing effects. However, to date, there has been no review published examining the antimicrobial benefits of lavender essential oil, specifically. Previous literature has shown that LEO and its constituents act synergistically with different antimicrobial agents to potentiate the antimicrobial activity. For the past decade, encapsulation of EOs with nanoparticles has been widely practiced due to increased antimicrobial effects and greater bioavailability as compared to non-encapsulated oils. Therefore, this review intends to provide an insight into the different aspects of antimicrobial activity exhibited by LEO and its constituents, discuss the synergistic effects displayed by combinatory therapy involving LEO, as well as to explore the significance of nano-encapsulation in boosting the antimicrobial effects of LEO; it is aimed that from the integration of these knowledge areas, combating AMR will be more than just a possibility. Full article

(This article belongs to the Special Issue Isolation and Utilization of Essential Oils: As Antimicrobials and Boosters of Antimicrobial Drug Activity)

19 pages, 547 KiB

Open AccessFeature PaperReview

Contribution of Essential Oils to the Fight against Microbial Biofilms—A Review

by Diana Camelia Nuță, Carmen Limban, Cornel Chiriță, Mariana Carmen Chifiriuc, Teodora Costea, Petre Ioniță, Ioana Nicolau and Irina Zarafu

Processes 2021, 9(3), 537; https://doi.org/10.3390/pr9030537 - 18 Mar 2021

Cited by 27 | Viewed by 4736

Abstract

The increasing clinical use of artificial medical devices raises the issue of microbial contamination, which is a risk factor for the occurrence of biofilm-associated infections. A huge amount of scientific data highlights the promising potential of essential oils (EOs) to be used for [...] Read more.

The increasing clinical use of artificial medical devices raises the issue of microbial contamination, which is a risk factor for the occurrence of biofilm-associated infections. A huge amount of scientific data highlights the promising potential of essential oils (EOs) to be used for the development of novel antibiofilm strategies. We aimed to review the relevant literature indexed in PubMed and Embase and to identify the recent directions in the field of EOs, as a new modality to eradicate microbial biofilms. We paid special attention to studies that explain the mechanisms of the microbicidal and antibiofilm activity of EOs, as well as their synergism with other antimicrobials. The EOs are difficult to test for their antimicrobial activity due to lipophilicity and volatility, so we have presented recent methods that facilitate these tests. There are presented the applications of EOs in chronic wounds and biofilm-mediated infection treatment, in the food industry and as air disinfectants. This analysis concludes that EOs are a source of antimicrobial agents that should not be neglected and that will probably provide new anti-infective therapeutic agents. Full article

(This article belongs to the Special Issue Isolation and Utilization of Essential Oils: As Antimicrobials and Boosters of Antimicrobial Drug Activity)

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47 pages, 57959 KiB

Open AccessReview

Chitosan-Coating Effect on the Characteristics of Liposomes: A Focus on Bioactive Compounds and Essential Oils: A Review

by Carine Sebaaly, Adriana Trifan, Elwira Sieniawska and Hélène Greige-Gerges

Processes 2021, 9(3), 445; https://doi.org/10.3390/pr9030445 - 01 Mar 2021

Cited by 50 | Viewed by 5876

Abstract

In recent years, liposomes have gained increasing attention for their potential applications as drug delivery systems in the pharmaceutic, cosmetic and food industries. However, they have a tendency to aggregate and are sensitive to degradation caused by several factors, which may limit their [...] Read more.

In recent years, liposomes have gained increasing attention for their potential applications as drug delivery systems in the pharmaceutic, cosmetic and food industries. However, they have a tendency to aggregate and are sensitive to degradation caused by several factors, which may limit their effectiveness. A promising approach to improve liposomal stability is to modify liposomal surfaces by forming polymeric layers. Among natural polymers, chitosan has received great interest due to its biocompatibility and biodegradability. This review discussed the characteristics of this combined system, called chitosomes, in comparison to those of conventional liposomes. The coating of liposomes with chitosan or its derivatives improved liposome stability, provided sustained drug release and increased drug penetration across mucus layers. The mechanisms behind these results are highlighted in this paper. Alternative assembly of polyelectrolytes using alginate, sodium hyaluronate, or pectin with chitosan could further improve the liposomal characteristics. Chitosomal encapsulation could also ensure targeted delivery and boost the antimicrobial efficacy of essential oils (EOs). Moreover, chitosomes could be an efficient tool to overcome the major drawbacks related to the chemical properties of EOs (low water solubility, sensitivity to oxygen, light, heat, and humidity) and their poor bioavailability. Overall, chitosomes could be considered as a promising strategy to enlarge the use of liposomes. Full article

(This article belongs to the Special Issue Isolation and Utilization of Essential Oils: As Antimicrobials and Boosters of Antimicrobial Drug Activity)

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