Selected plant essential oils and their main active components,a promising approach to inhibit aflatoxigenic fungi and aflatoxin production in food

Recent research has showed that Aspergillus flavus and Aspergillus parasiticus are aflatoxigenic species that can become very competitive in the framework of climate change. Aflatoxins show carcinogenic, mutagenic, immunotoxic and teratogenic effects on human and animals. Effective and sustainable measures to inhibit these species and aflatoxins in food are required. Origanum vulgare and Cinnamomum zeylanicum essential oils (EOs) and their major active constituents, carvacrol and cinnamaldehyde, respectively, were assayed for inhibiting these species and aflatoxin production in maize extract medium under different environmental conditions. Doses of 10–1000 mg l^?1 were assayed and the effective doses for 50 (ED₅₀) and 90% (ED₉₀) growth inhibition were determined. The ED₅₀ of cinnamaldehyde, carvacrol, oregano EO, and cinnamon EO against A. flavus were in the ranges 49–52.6, 98–145, 152–505, 295–560 mg l^?1 and against A. parasiticus in the ranges 46–55.5, 101–175, 260–425 and 490–675 mg l^?1, respectively, depending on environmental conditions. In A. flavus treatments ED₉₀ were in the ranges 89.7–90.5, 770–860 and 820–>1000 mg l^?1 for cinnamaldehyde, carvacrol and cinnamon EO, and in A. parasiticus treatments in the ranges 89–91, 855–>1000 and 900–>1000 mg l^?1, respectively. ED₉₀ values for oregano EO against both species were >1000 mg l^?1. Growth rates of both species were higher at 37 than at 25°C and at 0.99 than at 0.96 a_w. Aflatoxin production was higher at 25 than at 37°C. Stimulation of aflatoxin production was observed at low doses except for cinnamaldehyde treatments. The effectiveness of EOs and their main constituents to inhibit fungal growth and aflatoxin production in contact assays was lower than in vapour phase assays using bioactive EVOH-EO films previously reported.     

Effects of Tropical Citrus Essential Oils on Growth, Aflatoxin Production, and Ultrastructure Alterations of Aspergillus flavus and Aspergillus parasiticus

Ethyl acetate extracts and hydrodistillated essential oils from five cultivars of tropical citrus epicarps were evaluated for their inhibitory activities against Aspergillus fumigatus, Aspergillus niger, Aspergillus flavus, Aspergillus parasiticus, and Penicillium sp. using disk diffusion and broth microdilution assays. Essential oils prepared from kaffir lime (Citrus hystrix DC) and acid lime (Citrus aurantifolia Swingle) epicarps exhibited stronger antifungal activity to all fungi than their ethyl acetate extracts with minimum inhibitory concentration and minimum fungicidal concentration values of 0.56 and 1.13 mg/ml (dry matter), respectively, against aflatoxin-producing A. flavus and A. parasiticus. The dominant components of the essential oil from kaffir lime were limonene, citronellol, linalool, o-cymene, and camphene, whereas limonene and p-cymene were major components of acid lime essential oil. Pure limonene, citronellal, and citronellol were five to six times less fungicidal than the natural essential oils, indicating the synergistic activity of many active compounds present in the oils. Kaffir and acid lime essential oils significantly reduced aflatoxin production of A. flavus and A. parasiticus, particularly lime essential oil, which completely inhibited growth and aflatoxin production of A. flavus at the concentration of 2.25 mg/ml. Target cell damage caused by acid lime essential oil was investigated under transmission electron microscopy. Destructive alterations of plasma and nucleus membrane, loss of cytoplasm, vacuole fusion, and detachment of fibrillar layer were clearly exhibited in essential-oil-treated cells.     

Cinnamon essential oil and cinnamaldehyde in the control of bacterial biofilms formed on stainless steel surfaces

The antibacterial effects of Cinnamomum cassia essential oil (EO) and cinnamaldehyde were evaluated against single- and mixed-species cultivation of enteropathogenic Escherichia coli (EPEC) and Listeria monocytogenes attached to stainless steel. A central composite rotational design with two variables and eleven assays was used to optimize the concentrations (0.00–1.00% v/v for the EO and 0.00–0.80% v/v for cinnamaldehyde) and contact times (1–21 min). The models generated were validated, and the effectiveness of C. cassia EO and cinnamaldehyde was compared with that of commercially available chemical sanitizers. Cinnamaldehyde and C. cassia EO proved to be efficient alternatives to commercial chemical sanitizers in the reduction or elimination of sessile bacterial cells. The activity of these natural compounds was, in most cases, equivalent or superior to that of the chemical sanitizers tested. However, L. monocytogenes was more resistant than EPEC to C. cassia EO and cinnamaldehyde, and the bacterial association in mixed-species biofilms made them more susceptible to these compounds.     

Chitosan nanoencapsulation of Pogostemon cablin (Blanco) Benth. essential oil and its novel preservative effect for enhanced shelf life of stored Maize kernels during storage: Evaluation of its enhanced antifungal,antimycotoxin, antioxidant activities and possible mode of action

The present evaluation aimed to synthesis and characterise the Pogostemon cablin essential oil encapsulated chitosan nanoemulsion (PCEO-CN) and evaluated its antifungal antimycotoxin and antioxidant activities. A total of twenty-six different chemical compounds were identified from P. cablin essential oil (PCEO), among which patchoulol (34.93%), α-bulnesene (17.76%) and α-guaiene (15.44%) were recorded as major components. The average size of PCEO-CN was 18.20 nm. The PCEO-CN showed concentration-dependent broad-spectrum antifungal and antimycotoxin activities. The in vivo evaluation showed that PCEO-CN significantly protected maize seeds from mould-induced biodeterioration and aflatoxin B₁ biosynthesis for up to 30 days. The PCEO-CN significantly inhibits ergosterol biosynthesis and cellular integrities of A. flavus. Based on the present study, PCEO-CN could be used as a food preservative to control mould and mycotoxin contamination in stored maize.     

Assessment of Thymus vulgaris L. essential oil as a safe botanical preservative against post harvest fungal infestation of food commodities

A total of 14 odoriferous angiospermic essential oils were tested against the toxigenic strain of Aspergillus flavus. The essential oil of Thymus vulgaris L. showed highest antifungal efficacy. The thyme oil absolutely inhibited the mycelial growth of A. flavus at 0.7 μl ml^− 1 and exhibited a broad fungitoxic spectrum against eight different food contaminating fungi viz. Fusarium oxysporum, Cladosporium herbarum, Curvularia lunata, Aspergillus terreus, Aspergillus niger, Aspergillus fumigatus, Alternaria alternata and Botryodiploidia theobromae. The oil also showed significant antiaflatoxigenic efficacy as it completely arrested the aflatoxin B₁ production at 0.6 μl ml^− 1. Thyme oil as fungitoxicant was also found superior over most of the prevalent synthetic fungicides. The LC₅₀ of thyme oil against mice was recorded as 7142.85 μl kg^− 1 body weight indicating its non-mammalian toxicity and strengthening its safe exploitation as preservative for stored food commodities. The findings recommend the thyme oil as potential botanical preservative in eco-friendly control of biodeterioration of food commodities during storage.

Industrial relevance

The thyme essential oil may be recommended for large scale application as a plant based preservative for stored food items because of its strong antifungal as well as antiaflatoxigenic efficacy. Because of broad antimicrobial spectrum, more efficacy over prevalent synthetic preservatives as well as non-mammalian toxicity, the thyme essential oil may be formulated as a safe and economical plant based preservative against post harvest fungal infestation and aflatoxin contamination of food commodities.     

Evaluation of Cinnamomum tamala Oil and Its Phenylpropanoid Eugenol for Their Antifungal and Antiaflatoxigenic Activity

During screening of 20 plant extracts against toxigenic strain of Aspergillus flavus (SK 3NSt), the extract of Cinnamomum tamala was found to exhibit absolute fungitoxic activity (100% growth inhibition). Hence, essential oil of C. tamala was extracted and selected for further investigations. The selected oil was subsequently standardised through physico-chemical and fungitoxic properties. Minimum inhibitory concentration (MIC) of the oil for absolute inhibition of growth of the toxigenic strain of A. flavus (SK 3NSt) was found to be 150 μl/l and oil showed fungicidal nature at its respective MIC. The oil had a broad fungitoxic spectrum. It was found to be absolutely inhibitory to almost all the 11 fungi tested when its fungitoxic spectrum was assayed. The antifungal potency of oil was found to be greater in comparison to some prevalent synthetic fungicides. The oils had the potency to withstand high inoculum density. The oil remained active up to 2 years and was thermostable. In addition, the oil showed significant efficacy in arresting aflatoxin B₁ secretion by the toxigenic strain (SK 3NSt) of A. flavus at 750 μl/l. GC-MS analysis of the oil led to the identification of main components of oil viz. eugenol (45.58%), β-pinene (10.03%), β-myrcene (9.73%), β-ocimene (4.51%), β-costol (3.88%) and thujyl alcohol isomer (2.51%). The efficacy of C. tamala oil as aflatoxin B₁ suppressor is being reported for the first time. Eugenol, the major component of oil showed absolute antiaflatoxigenic efficacy even at 250 μl/l. The high LD₅₀ value (16.94 ml/kg body weight) of oil recorded on mice indicates its non-mammalian toxicity and suggests the recommendation of the oil as a novel and safe post-harvest biological preservative of food commodities for their preservation from contaminating fungi.     

Insecticidal activities of aromatic plant extracts and essential oils against Sitophilus oryzae and Callosobruchus chinensis

Methanol extracts from 30 aromatic medicinal plant species and five essential oils were tested for their insecticidal activities against adults of Sitophilus oryzae (L.) and Callosobruchus chinensis (L.), using direct contact application and fumigation methods. Responses varied with plant material, insect species, and exposure time. In a test with a filter paper diffusion method at 3.5 mg/cm², potent insecticidal activity against both species was produced by an extract from Cinnamomum cassia bark, cinnamon (C. cassia) oil, horseradish (Cocholeria aroracia) oil, and mustard (Brassica juncea) oil within 1 day after treatment. Over 90% mortality at 3 or 4 days after treatment was achieved using extracts of Acorus calamus var. angustatus rhizome, Acorus gramineus rhizome, Illicium verum fruit, and Foeniculum vulgare fruit. An extract from Cinnamomum sieboldii root bark gave 100% mortality at 2 days after treatment. At 0.7 mg/cm², extracts from C. cassia, C. sieboldii, and F. vulgare as well as cinnamon oil, horseradish oil and mustard oil were highly effective against both species. In a fumigation test with S. oryzae adults, the oils described were much more effective in closed containers than in open ones, indicating that the insecticidal activity of the oils was attributable to fumigant action. The plant extracts and essential oils described could be useful for managing field populations of S. oryzae and C. chinensis.     

Antifungal property of the essential oils and their constituents from Cinnamomum osmophloeum leaf against tree pathogenic fungi

This study compares the chemical constituents of leaf essential oils from various geographical provenances of Cinnamomum osmophloeum and investigates their antifungal activities against six tree pathogenic fungi. According to GC‐MS and cluster analyses, the leaf essential oils obtained from different geographical provenances and their relative contents were classified into six chemotypes: cinnamaldehyde type, cinnamaldehyde–cinnamyl acetate type, cinnamyl acetate type, linalool type, camphor type, and mixed type. Results from the antifungal tests show that the leaf essential oils of cinnamaldehyde type and cinnamaldehyde–cinnamyl acetate type have excellent inhibitory effect against Rhizoctonia solani, Collectotrichum gloeosporioides, Ganoderma australe and Fusarium solani. Furthermore, among the fourteen constituents of C osmophloeum leaf essential oils, Z‐cinnamaldehyde, eugenol, geraniol and citral display the best antifungal properties. Comparisons of the antifungal properties of Z‐cinnamaldehyde congeners reveal that Z‐cinnamaldehyde exhibits the best antifungal property of this group. Copyright © 2005 Society of Chemical Industry     

Fungitoxic activity of Indian borage (Plectranthus amboinicus) volatiles

Indian borage (Plectranthus amboinicus) was investigated for antifungal activity through agar well diffusion assay. Indian borage oil (IBO) was found to be effective against various fungi tested, as it inhibited the radial growth of mycelia and exhibited broad fungitoxic properties against Aspergillus flavus, Aspergillus niger, Aspergillus ochraceus CFR 221, Aspergillus oryzae, Candida versatilis, Fusarium sp. GF-1019, Penicillium sp., and Saccharomyces cerevisiae. The effective concentration of IBO on the growth of A. ochraceus in yeast extract sucrose medium was determined. IBO completely inhibited ochratoxin (OTA) production by the toxigenic strain A. ochraceus at 500 ppm. Also, the application of IBO at 100 mg/g in food samples resulted in inhibition of the growth of A. ochraceus in food systems such as groundnut, maize and poultry feed and no detectable amount of OTA was found at a high moisture level of 30%, even after seven days. IBO has the potential for use as a botanical fungitoxicant against fungal attack in stored food commodities.     

Assessment of Pelargonium graveolens oil as plant‐based antimicrobial and aflatoxin suppressor in food preservation

BACKGROUND: Contamination of stored food commodities by moulds and mycotoxins results in qualitative as well as quantitative losses. Most of the synthetic antimicrobials used for preservation of stored food items produce side effects in the form of residual and mammalian toxicity. Recently some higher plant products have been recommended as safe alternatives of such synthetic antimicrobials. In the present investigation antifungal efficacy of some essential oils was evaluated against two toxigenic strains of Aspergillus flavus with special reference to the oil of Pelargonium graveolens to investigate its potential to inhibit aflatoxin B₁ secretion. RESULTS: Essential oil of P. graveolens exhibited absolute fungitoxicity against both the toxigenic strains of A. flavus. The minimum inhibitory concentration of the oil was found to be 0.75 g L^?1 and exhibited a fungistatic nature. It was found superior over the synthetic fungicides tested and exhibited a broad fungitoxic spectrum. The oil showed excellent anti‐aflatoxigenic efficacy as it completely inhibited aflatoxin B₁ production even at 0.50 g L^?1. CONCLUSION: This is the first report on the aflatoxin B₁ inhibitory nature of P. graveolens oil. It may be recommended as a novel plant‐based antimicrobial as well as aflatoxin B₁ suppressor over synthetic preservatives in food protection. Copyright © 2008 Society of Chemical Industry     

Evaluation of some essential oils as botanical fungitoxicants for the protection of stored food commodities from fungal infestation

Essential oils from different parts of 18 plants belonging to 11 families were extracted and tested against two toxigenic strains of Aspergillus flavus Link through the poisoned food technique. The oil of Mentha arvensis was found to be effective against both strains of A. flavus and completely stopped the radial mycelial growth of A. flavus at 0.10 mg mL^?1. It was found to be superior over the synthetic fungicides tested and showed a broad fungitoxic spectrum against A. niger, A. fumigatus, Botryodiplodia theobromae, Cladosporium cladosporioides, Fusarium oxysporum, Helminthosporium oryzae, Macrophomina phaseolina and Sclerotium rolfsii at 0.10 mg mL^?1. The oil completely inhibited the aflatoxin B1 production by the toxigenic strain of A. flavus at 0.05 mg mL^?1. Moreover, the Mentha oil also exhibited potent antioxidant activity in 2,2′‐azino‐bis‐3‐ethylbenzothiazoline‐6‐sulphuric acid (ABTS) bioassay. Keeping in mind the side effects of synthetic pesticides and the global interest in botanical pesticides for plant protection due to their biodegradable nature, M. arvensis oil may be used as a botanical fungitoxicant against fungal attack to stored food commodities. The antiaflatoxigenic and antioxidant nature of the oil suggest the possibility of its exploitation for enhancing the shelf life of stored food commodities. Copyright © 2007 Society of Chemical Industry     

A comprehensive review of the physicochemical,quality and nutritional properties of Nigella sativa oil

Nigella sativa L. is an annual herb of the Ranunculaceae family, with the seeds called black cumin seed or black seed containing 34–39% oil. Its oil has many uses in traditional medicine and food industry. Black seed oil is a significant source of essential fatty acids, tocopherols (91–246 ppm), phytosterols (1993?2182 ppm), polyphenols (245–309 ppm), essential oils and other bioactive compounds. Thymoquinone is one of the important active compounds in the essential oil part of black seed oil with many health beneficial properties. Black seed oil is getting much attention either used alone or in combination with other vegetable oils. Therefore, providing information about the black seeds originating in different parts of the world, their oil composition and the effect of different oil extraction methods can be of great value. Environmental condition, cultivated areas, maturity period and storage conditions have significant effects on its properties. Black seed oil deserves more attention as a potential multi-purpose product. This article reviews the physicochemical properties, quality, and medicinal and nutritional aspects of black seed oil.     

ANTIFUNGAL ACTIVITIES OF THYME, CLOVE AND OREGANO ESSENTIAL OILS

The antifungal potential of essential oils of oregano (Origanum vulgare), thyme (Thymus vulgaris) and clove (Syzygium aromaticum) was determined. To establish this antifungal potential, two molds related to food spoilage, Aspergillus niger and Aspergillus flavus, were selected. The agar dilution method was employed for the determination of antifungal activities. The three essential oils analyzed presented inhibitory effects on both molds tested. Oregano essential oil showed the highest inhibition of mold growth, followed by clove and thyme. Aspergillus flavus was more sensitive to thyme essential oil than A. niger. Clove essential oil was a stronger inhibitor against A. niger than against A. flavus.     

Efficacy of Some Essential Oils Against Aspergillus flavus with Special Reference to Lippia alba Oil an Inhibitor of Fungal Proliferation and Aflatoxin B1 Production in Green Gram Seeds during Storage

During mycofloral analysis of green gram (Vigna radiata (L.) R. Wilczek) seed samples taken from different grocery stores by agar and standard blotter paper methods, 5 fungal species were identified, of which Aspergillus flavus exhibited higher relative frequency (75.20% to 80.60%) and was found to produce aflatoxin B₁. On screening of 11 plant essential oils against this mycotoxigenic fungi, Lippia alba essential oil was found to be most effective and showed absolute inhibition of mycelia growth at 0.28 μL/mL. The oil of L. alba was fungistatic and fungicidal at 0.14 and 0.28 μL/mL, respectively. Oil had broad range of fungitoxicity at its MIC value and was absolutely inhibited the AFB1 production level at 2.0 μL/mL. Chemical analysis of this oil revealed geranial (36.9%) and neral (29.3%) as major components followed by myrcene (18.6%). Application of a dose of 80 μL/0.25 L air of Lippia oil in the storage system significantly inhibited the fungal proliferation and aflatoxin production without affecting the seed germination rate. By the virtue of fungicidal, antiaflatoxigenic nature and potent efficacy in storage food system, L. alba oil can be commercialized as botanical fungicide for the protection of green gram seeds during storage.     

Extraction of essential oils from five cinnamon leaves and identification of their volatile compound compositions

Five cinnamon species, viz. Cinnamomum cassia, Cinnamomum zeylanicum, Cinnamomum tamala, Cinnamomum burmannii, Cinnamomum pauciflorum, were chosen to prepare essential oils by hydrodistillation and to identify and quantify their volatile compound compositions. C. cassia was determined to have the highest yield (1.54%) of essential oil, followed by C. zeylanicum, C. pauciflorum, C. burmannii and C. tamala. Gas chromatography/mass spectrometry (GC/MS) was used to identify and quantify the volatile compound composition. The results indicated the apparent difference in the volatile compound compositions of essential oils between species. The total numbers of volatile compounds identified from C. cassia, C. zeylanicum, C. tamala, C. burmannii and C. pauciflorum leaves were 22, 22, 13, 6 and 21, respectively. trans-Cinnamaldehyde was found in the essential oil of each species, which was also the major volatile component of C. cassia and C. burmannii leaves. Besides trans-cinnamaldehyde, 3-methoxy-1,2-propanediol was the main volatile compound of C. cassia leaf, while eugenol of C. zeylanicumand, C. pauciflorum and C. burmannii leaves, and 5-(2-propenyl)-1,3-benzodioxole of C. tamala leaf were also the main substances.Industrial relevanceThe essential oil of cinnamon is an important bioactive substance which has many disease prevention effects. In this work, five species of cinnamon leaves were chosen as materials to prepare the essential oils. The yield of essential oil was determined. The volatile compounds of essential oil were identified by GC/MS analysis. The results showed the significant difference of volatile compound composition between species. trans-Cinnamaldehyde was detected to exist in all the species tested as an important volatile component. This work is helpful for extensive development of this medicinal herb.     

Effect of UV-C irradiation on inactivation of Aspergillus flavus and Aspergillus parasiticus and quality parameters of roasted coffee bean (Coffea arabica L.)

ABSTRACT

This study investigated the antifungal effect of ultraviolet-C (UV-C) against Aspergillus flavus and Aspergillus parasiticus on roasted coffee beans. Also, any changes in the quality of the roasted coffee beans were measured after UV-C irradiation. As UV-C irradiation time increased (0–2 h), the number of surviving A. flavus and A. parasiticus spores significantly (P < .05) decreased. The reduction values of A. flavus in round part, crack part, and whole roasted coffee beans were 2.16, 0.71, and 1.58 log₁₀ CFU g^?1, respectively, and the reduction values of A. parasiticus in round part, crack part, and whole roasted coffee beans were 1.03, 0.37, and 0.72 log₁₀ CFU g^?1, respectively, after 2 h of UV-C irradiation. Field emission scanning electron microscopy showed that the morphology of A. flavus and A. parasiticus spores included expanded wrinkles that were deformed by UV-C irradiation. The Hunter colours were significantly reduced (P < .05). There was no significant change (P > .05) in moisture content, but the pH was significantly decreased (P < .05). Most of the sensory parameters did not change, but there was a significant difference (P < .05) in flavour. Based on this study, 2 h of UV-C irradiation was effective in reducing 90% of A. flavus, but it was not effective against A. parasiticus present on roasted coffee beans. Also, Hunter colour, pH, and sensory parameters (flavour) were changed by UV-C irradiation.     

Natural Control of Corn Postharvest Fungi Aspergillus flavus and Penicillium sp. Using Essential Oils from Plants Grown in Argentina

The objective in this study was to evaluate the antifungal activity of essential oils from native and commercial aromatic plants grown in Argentina against corn postharvest fungi and to link the essential oil bioactivity with lipid oxidation and morphological changes in fungus cell membrane. Essential oil (EO) of oregano variety Mendocino (OMen), Cordobes (OCor), and Compacto (OCom), mint variety Inglesa (Mi), and Pehaujo (Mp), Suico (Sui); rosemary (Ro), and Aguaribay (Ag) were tested in vitro against 4 corn fungi: A. flavus (CCC116–83 and BXC01), P. oxalicum (083296), and P. minioluteum (BXC03). The minimum fungicidal concentration (MFC) and the minimum inhibitory concentration (MIC) were determined. The chemical profiles of the EOs were analyzed by GC‐MS. Lipid oxidation in cell membrane of fungi was determined by hydroperoxides and related with essential oil antifungal activity. The major compounds were Thymol in OCor (18.66%), Omen (12.18%), and OCom (9.44%); menthol in Mi and Mp; verbenone in Sui; dehydroxy‐isocalamendiol in Ag; and eucaliptol in Ro. OCor, Omen, and OCom showed the best antifungal activity. No antifungal activity was observed in Ag and Ro EO. The hydroperoxide value depended on the fungi (P < 0.001) and the antimicrobial agent (P < 0.001).Membrane lipids were oxidized by Sui EO in A. flavus BXC01 and A. flavus CCC116–83 (0.021 and 0.027 meqO₂/kg, respectively). The results suggest that the EOs of OCor, OMen, OCom, Mi, Mp, and Sui grown in Argentina can be used as natural alternatives to control fungi that produce mycotoxin in maize.     

Contact and fumigant activities of aromatic plant extracts and essential oils against Lasioderma serricorne (Coleoptera: Anobiidae)

Methanol extracts from 30 aromatic medicinal plant species and five plant essential oils were tested for their insecticidal activities against Lasioderma serricorne (F.) adults using direct contact application and fumigation methods. Responses varied with plant material and exposure time. Good insecticidal activity against L. serricorne adults was achieved with extracts of Agastache rugosa whole plant, Cinnamomum cassia bark, Illicium verum fruit and Foeniculum vulgare fruit as well as cinnamon (C. cassia), horseradish (Cocholeria aroracia) and mustard (Brassica juncea) oils applied at 3.5 mg/cm² in a filter paper diffusion method. Over 90% mortality at 3 days after treatment was achieved with an extract of Acorus calamus var. angustatus rhizome. Cinnamon, horseradish and mustard oils, at 0.7 mg/cm², were highly toxic to the adult beetles 1 day after treatment. In a fumigation test with the beetle adults, insecticidal activity of horseradish oil, mustard oil and Foeniculum fruit extract was much more effective in closed cups than in open ones, indicating that the insecticidal activity of these materials was largely attributable to fumigant action. These naturally occurring plant extracts and essential oils could be useful for managing populations of L. serricorne.     

Chemical composition and antimicrobial activity of Vitex agnus-castus L. fruits and leaves essential oils

The following study deals with the chemical composition, antimicrobial activity of essential oils of Vitex agnus-castus L. and their main constituents in vitro and in vivo. The main compounds in the oil of unripe fruits were sabinene (17.8%) and 1,8-cineole (17.5%), while in the oil of the ripe fruits dominant compounds were 1,8-cineole (16.3%) and sabinene (13.4%). The leaves oil contained an abundance of 1,8-cineole (22.0%), as well. All of the oils tested were rich sources of α-pinene (12.2%, 9.4% and 9.4%, respectively). Antimicrobial activity was tested using bacterial and fungal strains by the microdilution method. Using the same technique 1,8-cineole and α-pinene showed very high antimicrobial potency as well. As 1,8-cineole was the predominant constituent of the oils, we have chosen to test it further in an in vivo experiment. Randomly chosen apples were treated with 1,8-cineol solution and infected with Aspergillus niger in order to provoke Aspergillus rot in apples. Disease incidence was recorded.