Antifungal Activity Of Essential Oils Research Articles

English

The individual antimicrobial activities of essential oils have been reported by many authors. However, there is little information about the effects of their mixtures in order to maximize their effect and reduce the growing resistance of pathogens to existing medicines. So, the aim of this work is to optimize the antibacterial and antifungal activities of essential oils from Plectranthus glandulosus, Ocimum gratissimum, Cymbopogon citratus, Cymbopogon nardus and Eucalyptus PF1. The mixtures of these essential oils were tested on seven bacterial and one fungal strain by employing the Mueller Hinton disc diffusion method. The diameters of the inhibition zones were measured after 24 h of incubation at 37°C. The results showed significant effects and regressions due to pure and composite mixtures on the response. The highest diameters of 30 and 27 mm were observed respectively with the pure essence of C. citratus on Candida albicans and the composite mixture. The binary mixtures showed more significant effects than the pure ones with the highest positive coefficient of regression 17.20 due to the Plectranthus glandulosus and Eucalyptus PF1 mixture on Pseudomonas aeruginosa. The growth inhibition data fitted the quadratic models for all individual strains except those of Staphylococcus aureus that better fitted the special cubic model. Some regression models of individual and combined microorganism responses have been proposed, as well as optimizations to maximize the inhibition zone diameters. Key words: Essential oils, mixtures, modeling, optimization, anti-microbial. &nbsp

Chemical composition and insecticidal, repellent and antifungal activities of essential oil of Mentha rotundifolia (L.) from Algeria

The biological struggle by the use of the natural substances that have a pesticide effect may be an alternative to harmful chemicals; among these natural substances are the extracts of aromatic plants especially essential oils. The present work aims to highlight the fungicidal and insecticidal effect of the essential oil (EO), of an aromatic plant Mentha rotundifolia, against respectively, a phytopathogenic mold (Fusarium culmorum) and the adults of two pests (Sitophilus granarius and Tribolium confusum) of stored grains. The evaluation of the chemical composition of the EO was carried out by gas chromatography coupled to mass spectrometry (GC/MS). The analysis made it possible to identify 27 compounds, which corresponds to 97.93 % of the totality of the oil of which the majority compounds are: Piperitenone oxide 35.49 ± 0.08, Caryophyllene oxide 35.27 ± 0.13 and cis-Cinerolone 10.95 ± 0.05. The bioassays to assess the EO toxicity towards the pest insects revealed a very high effect, which increases significantly with the dose and the time of exposure. Similarly, the test for the repellent effect shows that this extract is a powerful insect repellent. In addition, we found that both the liquid and vapor phases of the EO present an inhibitory effect of the growth of the fungal strain. In the light of the results obtained, the plant studied is promising as a source of natural pesticides and lends itself well to research in the field of pest control using biochemical alternatives.

An In Vitro Study on the Antimicrobial Properties of Essential Oil Modified Resin Composite against Oral Pathogens.

Modifying the composition of dental restorative materials with antimicrobial agents might induce their antibacterial potential against cariogenic bacteria, e.g., S. mutans and L. acidophilus, as well as antifungal effect on C. albicans that are major oral pathogens. Essential oils (EOs) are widely known for antimicrobial activity and are successfully used in dental industry. The study aimed at evaluating antibacterial and antifungal activity of EOs and composite resin material (CR) modified with EO against oral pathogens. Ten EOs (i.e., anise, cinnamon, citronella, clove, geranium, lavender, limette, mint, rosemary thyme) were tested using agar diffusion method. Cinnamon and thyme EOs showed significantly highest antibacterial activity against S. mutans and L. acidophilus among all tested EOs. Anise and limette EOs showed no antibacterial activity against S. mutans. All tested EOs exhibited antifungal activity against C. albicans, whereas cinnamon EO showed significantly highest and limette EO significantly lowest activity. Next, 1, 2 or 5 µL of cinnamon EO was introduced into 2 g of CR and microbiologically tested. The modified CR showed higher antimicrobial activity in comparison to unmodified one. CR containing 2 µL of EO showed the best antimicrobial properties against S. mutans and C. albicans, while CR modified with 1 µL of EO showed the best antimicrobial properties against L. acidophilus.

The antifungal activity of essential oils from some plants in Vietnam against the pathogenic fungi Candida albicans and Aspergillus fumigatus

The antifungal activity of essential oils from some plants in Vietnam against the pathogenic fungi Candida albicans and Aspergillus fumigatus

An in Vitro Study on Antifungal Properties, Total Polyphenolic Content and Antioxidant Activity of Different Parts of Selected Fruit Trees

The purpose of this study was to investigate the antifungal properties, total polyphenolic content and antioxidant activity of sapwood, heartwood and bark parts obtained from three different fruit trees; olive (Olea europaea L.), loquat (Eriobotrya japonica Lindl.) and date plum (Diospyros lotus L.) grown in Turkey. Firstly, the hydrodistillation products (essential oil, hydrosol, hot-water extract) were acquired from these parts of selected trees, and methanol and ethanol extracts of the same samples were also prepared for the analysis. The antifungal activities of essential oil, hydrosol, hot-water extract, ethanol and methanol extracts were determined against wood-rot fungus Coniophora puteana. In addition, polyphenol contents and antioxidant activities of ethanol and methanol extracts were investigated. According to the results, generally, the essential oil of the parts of three fruit trees was found to inhibit the fungal growth. All hot water extracts and hydrosols of these trees showed no antifungal activity against C. puteana. It was found that olive tree had higher antifungal activity than loquat and date plum trees. The methanol extract of loquat bark gave the highest total phenolic content, total flavonoid content and condensed tannin content compared to parts of the other trees. Furthermore, the highest total polyphenol content and antioxidant activity among three fruit trees were determined in ethanol and methanol extracts of the bark and heartwood of loquat tree. Based on these findings, it can be concluded that the parts of studied fruit trees have less or more antifungal and antioxidant activity depending on the experimental parameters, and therefore they can be evaluated as alternative natural antifungal and antioxidant sources.

Chemical characterization and determination of in vivo and in vitro antifungal activity of essential oils from four Eucalyptus species against the Hemileia vastatrix Berk and Br fungus, the agent of coffee leaf rust

Essential oils, also known as volatile oils, are substances produced through the secondary metabolism of plants. In this study, we determined the chemical composition and the in vitro and in vivo antifungal activity of the essential oils from four species of Eucalyptus, Eucalyptus citriodora, Eucalyptus camaldulensis, Eucalyptus grandis and Eucalyptus microcorys, against the Hemileia vastatrix fungus. The essential oils from these four species of Eucalyptus were extracted from their leaves by the hydrodistillation technique using a modified Clevenger apparatus. The chemical characterization was performed by gas chromatography coupled with a mass spectrometer detector and by gas chromatography using a flame ionization detector. The antifungal activities of the essential oils against H. vastatrix were studied by evaluating the percentage of spore germination using the microdilution test for in vitro assays. The curative and preventive effects were evaluated in in vivo tests. The principal constituents of the essential oil from E. citriodora were citronellal, citronellol and isopulegol, while E. camaldulensis produced 1,8-cineole, α-terpineol and α-pinene. 1,8-cineole, α-pinene and α-terpineol were obtained from E. grandis and 1,8-cineole, α-pinene and trans-pinocarveol were the principal components in the essential oil of E. microcorys. In vitro and in vivo antifungal activities against the fungus under study were observed for most of the essential oils, except the essential oil from E. microcorys, for which no preventive antifungal activity was observed. Only the curing of infection by the H. vastatrix fungus was observed with this oil.

Chemical Composition and Antifungal Activity of Essential Oil of Thymus vulgaris Grown in Iran against Some Plant Pathogenic Fungi

This study was designed to examine the chemical composition and in vitro antifungal activity of hydrodistillation essential oil from the aerial parts of Thymus vulgaris. The chemical compounds were analyzed by GC and GC/MS. The oil analysis resulted in the identification of 45 compounds representing 96.75% of the oil. Thymol (36.81 %) and ρ-cymene (30.90 %) were the main components of the oil. The oil was tested for in vitro antifungal activity against three phytopathogenic fungi included Drechslera spicifera, Fusarium oxysporum f.sp. ciceris and Macrophomina phaseolina by the agar dilution method. According to the results of the antifungal assay, the antifungal activity of the oil increased with rising in concentration. All of the tested concentrations of essential oil could completely inhibit fungal growth on 1600 μLL-1. Although thyme oil on 800 μLL-1 was not completely effective against the M. phaseolina, prevented from mycelia growth of other fungi, perfectly. In this study fungicidal activity only was observed on F. oxysporum and D. spicifera at higher concentrations than 800 μLL-1. The antifungal activity of T. vulgaris essential oil probably due to the high concentration of oxygenated monoterpenes (thymol) and monoterpene hydrocarbons (ρ-cymene).

Chemical Composition and Efficacy of Ocimum basilicum L. Essential Oil against Stored Rice (Oryza sativa L.) Molds Sold in Ngaoundere (Cameroon)

The aimed of this study to evaluate the antifungal activity of essential oils of Ocimum basilicum L. on some fungi isolated from commercial rice sold in Cameroon. Fungal isolates were primarily identified based on morphological characteristics, while representative isolates were identified using PCR-based methods. Essential oils were extracted by hydro-distillation, chemical composition was analyzed by gas chromatography coupled with mass spectrometry (GC-MS) and antifungal activity against isolated fungi were assessed using the micro-atmospheric method. The percentage of frequency and abundance varied with the sample analyzed and the fungi detected. A total of 85 fungal isolates of eight genera including Aspergillus, Fusarium, Penicillium, Rhizopus, Cladosporum, Mucor Alternaria and Acremonium in decreasing order of predominance were identified. The most fungal species identified were Aspergillus flavus, A. fumgatis, A. niger, A. carbonarius, Fusarium oxysporum, F. graminarum, F. moniliforme, Penicillium citrinum, P. expansum, Rhizopus oryzea, Cladosporum sp, Mucor hiemalis, Alternaria solani, Acremonium murorum. More than 61% (A. flavus, A. niger, P. citrinum) and 44% (M. hiemalis, A. flavus, A. niger) of analyzed samples contain respectively aflatoxin B1, AFB1 (0 - 17.3 µg/kg) and ochratoxin A, OTA (0 - 5.2 µg/kg). Citrinin was not detected. The main compounds identified in O. basilicum EO are eugenol (30.6), linalool (29.5), cineole (14.4), Terpinen-4-ol (5.6), 2-norpinen (4.1), Cadinen (3.3), Limonen (2.4) and (E)-β-Ocimene (2.2). The O. basilicum EO exhibit antifungal activity with the MIC range from 750-2000 ppm. This activity varies with the strains and the concentration of EO. The increased prevalence of mycotoxigenic fungi in rice, a highly consumed food grain in Africa, poses serious health concerns to the general public. The O. basilicum EO can therefore be used as alternatives to synthetic pesticide in rice storage.

Mycotoxins Content of Smoked Fishes Sampled on Market Stalls of Ngaoundere and Antifungal Activity of Essential Oils of Cymbopogon citratus and Ocimum basilicum against Mycotoxin Producing Strains

Aim: The aim of this study was to evaluate the sanitary quality of smoked fish by determining their mycotoxin content, and also the chemical composition, antifungal activity of Cymbopogon citratus and Ocimum basilicum essential oils from Cameroon against some mycotoxigenic fungal strains responsible of the smoked fish biodegradation.
 Place and Duration of Study: Laboratory of Food Microbiology and Biotechnology, National School of Agro-Industrial Sciences, University of Ngaoundere, Cameroon, from August 2019 to April 2020.
 Methodology: Fifteen samples of smoked fishes have been collected in August 2019 from “petit marché” market (Ngaoundere, Cameroon). Physico-chemical parameters of smoked fishes were evaluated. Mycotoxin (AFB1, CIT, and OTA) contents have been determined with HPLC. Isolation and identification of molds were done using their macroscopic and microscopic characteristics, and the identity of the strains was done by PCR sequencing methods. For plants, 15 kg of Cymbopogon citratus leaves and 5 kg of Ocimum basilicum leaves have been harvested on 10 September 2019 in Ngaoundere and used for the essential oil’s extraction. Essential oil extraction has been done through hydrodistillation and the determination of its chemical composition done with GC/MS.
 Results: Major part of samples contains at least one mycotoxin, in quantities which are beyond the safe dose. Eleven species of molds have been identified: Aspergillus spp., Penicillium citrinum, and Mucor hiemalis. Amongst the isolated species, those which can produce mycotoxins are: Penicillium citrinum, Aspergillus versicolor, Aspergillus fumigatus, Aspergillus carbonarius, Aspergillus niger, and Fusarium moniliforme. Geranial (42.4%), Neral (33.5%) and Myrcene (10.8%) are major compounds found in the essential oil of C. citratus while monoterpens (60.8%), Eugenol (30.7%), Linalol (29.4%) and 1,8-Cineol (14.3%) are the major compounds found in the essential oil of O. basilicum. 
 Conclusion: Essential oils of C. citratus and O. basilicum are efficient against isolated toxigenic species. C. citratus being more efficient than O. basilicum.

A comparative study of the antifungal activity of essential oils of Varronia curassavica Jacq. obtained by different distillation methods

This work aimed to compare the antifungal activity of the essential oil of Varronia curassavica obtained by hydrodistillation and microwave against the fungus Colletotrichum musae and verify the alterations caused by these extraction methods on the leaf surface. This study used four essential oil samples obtained by different methods, two by hydrodistillation [HD1 (1.0 L of water and 100 min.) and HD2 (2.0 L of water and 140 min.)] and two by microwave [MI1 (500W, 20 min, without water) and MI2 (700W, 40 min, with 50 mL of water added to fresh leaves)]. Essential oils concentrations of 0.05, 0.1, 0.5, 1.0, and 3.0% (v / v) were tested in PDA medium. The mycelial growth of C. musae was evaluated by measuring the diameter, every 24 hours up to 144 hours after the beginning of the incubation. Untreated leaves and leaves treated with HD1 and MI1 were prepared for observation in a scanning electron microscope (SEM) LEO EVO 40. The most abundant compounds detected in the essential oil samples analyzed by gas chromatography were: shyobunol, germacrene D-4-ol, E-caryophyllene, bicyclogermacrene, and α-cadinol. Up to 72 hours after the beginning of the incubation, C. musae presented no mycelial growth, even at the lowest essential oil concentration. Conversely, mycelial growth was detected in the control (PDA + DMSO) from 24 hours after incubation. At 144 hours after incubation, regardless of the concentration, the essential oil samples obtained by HD provided lower mycelial growth of C. musae (1.49 cm) when compared with samples obtained by MI (1.80 cm). This difference possibly occurred due to the reduction to less than half of the germacrene D-4-ol content in the samples obtained by MI. The four essential oil samples tested inhibited the mycelial growth and thus presented a inhibitory effect on C. musae. The SEM revealed more drastic changes on the surface of the leaf treated with MI than on those treated with HD. The essential oil of V. curassavica, mainly when obtained by hydrodistillation, has the potential for use in the control of C. musae.

Phytoncide action of essential oils of medicinal plants on the causative agents of broad beans alternariosis and cladosporiosis

Relevance. The use of chemical fungicides in protecting plants from pathogens is the most common way, despite the proven danger of pesticides. The use of biofungicides based on essential oils of medicinal plants, which also have phytoncidal properties, can be a suitable alternative to chemical preparations. In the years favorable for the development of alternariosis or cladosporiosis, spots appear on the plants, leading to necrosis and significant loss of seed productivity. Therefore, the search for new effective and safe means of combating fungal phytopathogens becomes relevant.Methods. Alternaria alternata (2018-1.1) and Cladosporium cladosporioides (2019-11.4) strains were isolated from leaves with signs of alternariosis and cladosporiosis, on which the essential oils Abies alba, Artemisia vulgaris, Caryophyllus aromaticus, Coriandrum sativum, Lavandula officinalis, Ocimum basilicum, Pimpinella anisum, Rosmarinus officinalis, Salvia sclarea, Thymus vulgaris. The antifungal activity of essential oils was evaluated by comparing the diameter of the experimental (with the addition of essential oil to the Petri dish) and control colonies using the author’s scale.Results. All studied essential oils had antifungal properties, but species-specificity was observed. Essential oils of basil, coriander and thyme showed a fungicidal effect on C. cladosporioides and A. alternata. Lavender oil proved to be a fungicide for A. alternata and a strong fungistatic for C. cladosporioides. To create biological products for plant protection against alternariosis, sage essential oil (moderate fungistatic effect) may also be of interest, and cladosporiosis - anise and rosemary oils.

Screening the antifungal activities of monoterpenes and their isomers against Candida species.

Increasing the occurrence of non-albicans Candida species with intrinsic or acquired resistance to antifungals as well as the emergence of multidrug Candida species coupled with the limited antifungal agents challenges the treatment of candidiasis. Consequently, a class of secondary metabolites of plants exhibiting decent antifungal activity. Therefore, this study aimed to evaluate the antifungal potential of various monoterpenes including Carvone, Limonene, Pinene, Menthone, Menthol, Camphor, Thujone, Citronellol, and Piperitone against standard and clinical isolates of Candida. Minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of compounds were determined, using the broth Microdilution method based on M27-A3 protocol documented by clinical laboratory standard institute (CLSI). Amongst the tested monoterpenes, oxygenated terpenoids showed strong antifungal activity. Specifically, alcoholic terpenoids such as (±)-Citronellol possess more efficacy than the corresponding ketonic ones with MICs ranging from 0·03 to 2·00μlml-1 (0·16-10·80mmoll-1 ). Among the examined yeasts, Candida tropicalis was the most susceptible species to (±)-Citronellol. Moreover, the examined monoterpenes successfully inhibited the growth of fluconazole-resistant Candida species. Moreover, statistical analysis showed no statistically significant difference between the (+) and (-) isomers, except for (±)-α-Pienene and (±) Menthone (ρ-value<0·05). Among the tested monoterpenes, (±)-Citronellol was the most potent compounds followed by (+)-α-Pinene and Menthol. Considering the significant antifungal activity of the examined monoterpenes, they could be used in controlling or treating candidiasis. Those potent antifungal monoterpenes with GRAS status in addition to their pleasant taste and odour make them appropriate additive or preservative compounds in food and cosmetics products. Furthermore, these data might help researchers to predict EOs antifungal activities, after determining its constituents. This study provides new information about the antifungal activities of monoterpenes and their isomers presented widely in essential oils. Screening results against pathogenic yeasts confirm the correlation between the chemical structure of tested monoterpenes and their antifungal effects. The present findings might be helpful to anticipate the antifungal activity of essential oils.

Physicochemical evaluation and antioxidant and antifungal activities of essential oils from Bauhinia forficata Link. and Bauhinia variegata L. flowers

&lt;em&gt;Bauhinia forficata&lt;/em&gt; essential oil showed good extraction yield. The CG-MS analysis showed 5 major compounds α-copaene, geraniol, α-bisabolene, caryophyllene and germacrene A. The percentage of mycelial inhibition in vitro showed higher sensitivity for &lt;em&gt;S. sclerotiorum&lt;/em&gt; and &lt;em&gt;A. flavus&lt;/em&gt; strains, the opposite was observed in &lt;em&gt;C. gloeosporioides&lt;/em&gt; that showed to be more resistant to essential oil concentrations. Future work may be carried out by evaluating the essential oil of &lt;em&gt;B. forficata&lt;/em&gt; flowers in a greenhouse and in the field by sprinkling or encapsulated micro or nano.

Antifungal and Phytotoxic Activities of Essential Oils: In Vitro Assays and Their Potential Use in Crop Protection

(1) Background: The use of natural products based on essential oils (EO) is nowadays arousing great interest as an alternative method to control plant pathogens and weeds. However, EO possess low bioavailability and are highly volatile, and their encapsulation in hydroxypropyl-ß-cyclodextrin (HP-β-CD) could be a means to enhance their stability and maintain their bioactivity. Thus, the current study aims at investigating, in the presence and the absence of HP-β-CD, the antifungal and phytotoxic activities of nine EO, distilled from plant species belonging to Alliaceae, Apiaceae, and Cupressaceae families, with considerations for their chemical composition. (2) Methods: EO antifungal activity was assessed by direct contact and volatility assays against Fusarium culmorum, a major phytopathogenic fungi, while phytotoxic effects were evaluated against lettuce (Lactuca sativa L.) and rye-grass (Lolium perenne L.), by seedling’s emergence and growth assays. (3) Results: These EO inhibit fungal growth in both direct contact and volatility assays, with half-maximal inhibitory concentrations (IC50) ranging from 0.01 to 4.2 g L−1, and from 0.08 up to 25.6 g L−1, respectively. Concerning phytotoxicity, these EO have shown great potential in inhibiting lettuce (IC50 ranging from 0.0008 up to 0.3 g L−1) and rye-grass (IC50 ranging from 0.01 to 0.8 g L−1) seedlings’ emergence and growth. However, the EO encapsulation in HP-β-CD has not shown a significant improvement in EO biological properties in our experimental conditions. (4) Conclusion: All tested EO present antifungal and phytotoxic activities, with diverse efficacy regarding their chemical composition, whilst no increase of their biological effects was observed with HP-β-CD.

Determination of chemical compositions and antifungal activities of laurel and fennel essential oils against fungal disease agents of cypress seedlings

Fusarium oxysporum and Pestalotiopsis funerea are the most common fungal disease agents of conifer seedlings causing root rot and shoot or tip blight diseases. In this study, chemical compositions and antifungal activities of essential oils of fennel (Foeniculum vulgare Mill.) and laurel (Laurus nobilis L.) were determined against root rot and wilt disease agents F. oxysporum and P. funerea in vitro conditions. Chemical compositions of essential oils were determined by using GC-MS analysis. Antifungal volatile phase effects of essential oils were determined on inhibition of mycelial growth in vitro conditions by using different concentrations. The effect of most effective concentrations of essential oils on the morphology of fungal hypha was also determined by using light microscope. GC-MS analysis of essential oils of laurel and fennel plants revealed that eucalyptol (46.97%) and α-terpinyl acetate (19.82%) were major components of laurel; trans-anethole (82.44%) and limonene (5.18%) were major components of fennel essential oils. Volatile phase effects of fennel and laurel essential oils were found to completely inhibit mycelial growth of F. oxysporum at 30.0 and 50.0 µl petri-1 concentrations, respectively. Complete growth inhibition of P. funerea by essential oil of fennel and laurel were observed at relatively lower concentrations (20.0 and 25.0 µl petri-1 concentrations, respectively). Light microscopic observations on hyphae, exposed to volatile phase of the most efficient concentrations of essential oil, revealed considerable structural deformations such as cytoplasmic coagulation, vacuolations and protoplast leakage. In conclusion, our results suggest that essential oils have the potential for use in control of fungal diseases of conifer plants.

Bioactive potential of Cedrus deodara (Roxb.) Loud essential oil (bark) against Curvularia lunata and molecular docking studies

A focus on evaluation of in vitro antifungal activity of essential oil of Cedrus deodara (bark), against fungus Curvularia lunata was studied. In this study, the essential oil was extracted via hydro distillation method, further chemical compositions were identified by GC–MS and antifungal potential was assessed against three pathogenic fungal strains viz., Alternaria alternata, Curvularia lunata and Bipolaris spicifera through poison food technique. The essential oil showed strong antifungal potential against Curvularia lunata, further leading to isolation of antifungal fraction using TLC bioautography against Curvularia lunata, the identification revealed the presence of ten molecules in antifungal fraction identified through GC–MS. Additionally, molecular docking study was applied to validate antifungal activity and results predicts strong binding affinity of isolated antifungal molecules with an important virulence factor of Curvularia lunata, a melanin biosynthetic enzyme trihydroxy naphthalene reductase (PDB ID-1YBV) confirming it antifungal potential. Thus, obtained results suggested the importance of essential oil from Cedrus deodara (bark) as a beneficial native source of the compounds with antifungal properties.

In Vitro and In Vivo Antifungal Activity of Clove (Eugenia caryophyllata) and Pepper (Piper nigrum L.) Essential Oils and Functional Extracts Against Fusarium oxysporum and Aspergillus niger in Tomato (Solanum lycopersicum L.).

In this study, hydrodistillation was used to obtain essential oils (EOs) from pepper (Piper nigrum L.) and clove (Eugenia caryophyllata) and co-hydrodistillation (addition of fatty acid ethyl esters as extraction co-solvents) was used to obtain functional extracts (FEs). Antifungal activity of EOs and FEs was evaluated by determination of minimum inhibitory concentration (MIC) against Fusarium oxysporum and Aspergillus niger. The results showed that pepper (Piper nigrum) and clove (Eugenia caryophyllata) essential oils and their functional extracts are effective in vitro at concentrations from 400 to 500 ppm after 10 days of culturing. The essential oils and functional extracts were used on tomato fruit samples at three different concentrations: 350, 400, and 450 ppm5. Clove essential oil reduced the growth of Aspergillus niger from 50% to 70% and Fusarium oxysporum to 40%. The functional extracts (FEs) of clove and pepper, mixed with ethyl decanoate (FEs-C10), were the best combination for protecting the tomato fruit in vivo against both phytopathogenic fungi. Gas chromatography-mass spectrometry (GC-MS) was used to identify eugenol as the principal compound in clove oil and limonene, sabinene, and β-caryophyllene in pepper oil.

Assessment of Mint, Basil, and Lavender Essential Oil Vapor-Phase in Antifungal Protection and Lemon Fruit Quality.

There is an increasing interest in developing natural methods to replace the current chemicals used for maintaining postharvest quality of citrus fruits. The essential oil antifungal activity of mint (MEO), basil (BEO), and lavender (LEO) acting as the vapor-phases was tested against Penicillium digitatum. The minimum doses with fungistatic and fungicidal effect, in vitro, acting as the vapor-phases, were set up. The minimum fungicidal dose was 300 μL for BEO and 350 μL LEO, while for MEO only minimal dose with fungistatic effect was reached. The IC50 values were calculated and used (v/v) for testing preservation of lemon fruits, in close space enriched in vapor oil. For this purpose, the following two independent in vivo experiments were carried out: experiment 1, inoculated lemons with P. digitatum stored without chemical treatments 7 days, at 22 ± 2 °C, at two concentrations (C1—IC50 equivalent; C2—half of C1); and experiment 2, the non-inoculated lemons kept under the same conditions and concentrations of EO vapor served to evaluate the lemon quality properties. The results showed that antifungal protective effect was provided in the order of LEO-C1 > BEO-C1 > MEO-C1 > BEO-C2 > MEO-C2 > LEO-C2. The quality indicators like weight loss, pH, and firmness were not negatively influenced.

PHYTONCIDAL ACTIVITY OF ESSENTIAL OILS OF MEDICINAL PLANTS TO SOME STRAINS OF MOLD FUNGI

Herbal antiseptics with phytoncidal action, for example, plant essential oils, can be used indoors in the presence of people. The antifungal activity of essential oils of medicinal plants (anis, basil, clary cage, clove, coriander, jasmine, juniper, lavender, lemon, orchid, rose, rosemary, tea tree, wormwood, ylang ylang) was evaluated by the degree of growth inhibition of mold colonies Alternaria alternata , Aspergillus oryzae, Aspergillus flavus, and Cladosporium cladosporioides. Colonies incubated in Petri dishes with a drop of essential oil on the lid under control petrolatum. All essential oils in the experiment had phytoncidal properties. The oils were divided into groups: 1 with fungicidal action (coriander, jasmine, orchid, rose); 2 with high fungistatic activity to all strains (lavender, basil, tea tree oil); 3 with fungistatic properties against individual strains (C. cladosporioides rosemary and anise, A. alternata and A. flavus lemon, A. oryzae wormwood); 4 with a stimulating effect of the growth of colonies A. oryzae lemon oil.

Potent Antifungal Activity of Essential Oil from Morinda Citrifolia Fruits Rich in Short-chain Fatty Acids

ABSTRACT The fruit of the Morinda citrifolia species popularly known as “noni” has been widely used in folk medicine for diverse therapeutic purposes including in the treatment of infectious diseases. Given this, we tested the essential oil from M. citrifolia fruits obtained by hydrodistillation against fungi and bacteria. The oil was rich in short-chain fatty acids: octanoic acid (38.7%) and hexanoic acid (20.0%) were identified as the major constituents after analysis of oil by GC/MS. The oil showed antimicrobial activity against all the microorganisms tested, mainly against fungi Candida albicans and C. utilise with minimal inhibitory concentration of 39 and 78 μg.mL−1, respectively. The antimicrobial potential of the oil was drastically reduced after it was subjected to the esterification reaction, indicating that the carboxyl group is responsible for the strong oil activity.