scholarly journals Antifungal Activity and Detoxification of Aflatoxins by Plant Extracts: Potential for Food Applications

2018 ◽  
Vol 10 (1) ◽  
pp. 24-32 ◽  
Author(s):  
Bárbara Ponzilacqua ◽  
Carlos Humberto Corassin ◽  
Carlos Augusto Fernandes Oliveira

Aflatoxins are secondary metabolites produced by fungi of the genusAspergillus, which occur naturally in cereals like corn, beans and rice. Aflatoxin B1causes an extensive number of toxic effects in animals and humans. This mycotoxin is a stable term and can act in low concentrations due to their higher toxicity. Management to prevent commodities aflatoxin contamination is essential during the production, mainly in pre- and post-harvest steps. A number of essential oils and aqueous plant extracts have been reported to be fungal growth inhibitors and may provide an attractive alternative to prevent aflatoxin contamination in foods. Thus, the aim of this review is to highlight recent data on thein vitroantifungal activity of essential oils and aqueous extracts from plants and discuss the perspectives of their use in food products.

2021 ◽  
Vol 10 (6) ◽  
pp. 10
Author(s):  
Saifeldin A. F. El-Nagerabi ◽  
Mohammed S. R. Al-Maqbali ◽  
Khalid M. S. Alabri ◽  
Abdulkadir E. Elshafie

Aflatoxins and especially aflatoxin B, are the devastating contaminant of food and feed products with hazardous effects to mankind and his domestic animals. These investigations were set to evaluate the effect of various levels of Commiphora myrrha resin (1.0, 1.25, 2.25, and 3.25 g/100 ml) and Prunus mahaleb seed extract (0.75, 1.5, 2.5, and 3.5 g/100 ml) on the growth and aflatoxin secretion by two aflatoxigenic strains of Aspergillus flavus and A. parasiticus. The two plant extracts significantly (p<0.05) decreased aflatoxin secretion, and inhibited the fungal growth. Resin of C. myrrha displayed 51.9-95.7% reduction in total aflatoxin secretion by A. flavus, and 46.9-92% for A. parasiticus, and Seed extract of P. mahaleb decreased aflatoxin up to 53.7-95.8% and 40-94.7%, respectively. The inhibition of aflatoxin B (B1 and B2) by myrrh resin and seed extract of mahaleb ranged between 51.7-93.5, 50-93.6% (A. flavus) and 39.5-89.7%, 37.9-93% (A. parasiticus). The mycelial dry weight of A. flavus and A. parasiticus ws decreased up to 46.1-58.7%, 28.9-51.3% (Myrrh resin), and between 45-56.9%, 33.3-55.9% (Mahaleb seed extract). Nonetheless, the two plant extracts did not detoxify aflatoxin B1. Therefore, it apparent that the resin of C. myrrha and seed extract of P. mahaleb affected the biosynthesis pathway of aflatoxins. Thus, they can be recommended as effective natural plant biopreservative against aflatoxin contamination of food and feed products.


Toxins ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 646 ◽  
Author(s):  
García-Díaz ◽  
Patiño ◽  
Vázquez ◽  
Gil-Serna

Aflatoxin (AF) contamination of maize is a major concern for food safety. The use of chemical fungicides is controversial, and it is necessary to develop new effective methods to control Aspergillus flavus growth and, therefore, to avoid the presence of AFs in grains. In this work, we tested in vitro the effect of six essential oils (EOs) extracted from aromatic plants. We selected those from Satureja montana and Origanum virens because they show high levels of antifungal and antitoxigenic activity at low concentrations against A. flavus. EOs are highly volatile compounds and we have developed a new niosome-based encapsulation method to extend their shelf life and activity. These new formulations have been successfully applied to reduce fungal growth and AF accumulation in maize grains in a small-scale test, as well as placing the maize into polypropylene woven bags to simulate common storage conditions. In this latter case, the antifungal properties lasted up to 75 days after the first application.


2013 ◽  
Vol 2 (4) ◽  
pp. 68 ◽  
Author(s):  
Saifeldin Ahmed El-nagerabi ◽  
Abdulkadir E. Elshafie ◽  
Mohamed R. Elamin

<p>Aflatoxin and especially aflatoxin B<sub>1</sub> (AFB<sub>1</sub>) is a carcinogenic secondary metabolite synthesized by certain <em>Aspergillus </em>species. They contaminate natural and processed agricultural and animal products which render them unfit for consumption. The aim of this study was to evaluate the <em>in vitro</em> effects of <em>Balanites aegyptiaca</em> and <em>Tamarindus indica</em> fruit extracts on the growth and aflatoxin secretion of <em>Aspergillus flavus</em> (SQU21) and <em>A. parasiticus </em>(CBS921.7) strains. The two fruit extracts significantly (<em>P </em>&lt; 0.05) reduced aflatoxin and did not inhibit mycelial dry weights of the two <em>Aspergillus </em>strains. At different concentrations of balanites (2.5-10%), the inhibition of total aflatoxin was 49.9-84.8% for <em>A. flavus</em> (SQU21) and 32.1-84.4% for <em>A. parasiticus</em> (CBS921.7), whereas the inhibition of aflatoxin Bwas 38.2-81.4% and 32.8-80.6% for the two strains. Tamarind fruit extract (2.5-7.5%) caused 28.8-84.2% and 40.7-85.5% reductions in total aflatoxin and 37.1-83.5% and 33.9-85.9% in aflatoxin B for the two strains, respectively. None of these extracts inhibited the fungal growth or detoxified synthetic aflatoxin B<sub>1</sub>. We have concluded that these fruits contain various inhibitors to aflatoxin biosynthesis and secretion. Therefore, they can be used in combination as safe green biopreservatives to combat aflatoxin contamination of food.</p>


2021 ◽  
Vol 52 (3) ◽  
pp. 49-59
Author(s):  
B. Karsou ◽  
R. Samara

Abstract This study investigated the role of endogenous Palestinian plant extracts in inducing wheat and barley resistance systems against loose smut disease with the aim to alternate the chemical pest control with natural fungicides. Twenty indigenous herbal plant extracts and essential oils were assessed for their biological and antifungal properties against Ustilago tritici and Ustilago nuda. Their potential role in inducing resistance pathways was studied on four different cultivars of wheat and barley. Two common enzyme indicators – guaiacol peroxidase (POX) and polyphenol oxidase (PPO) – are expressed in plants only after physical or chemical induction. The antifungal activity of the plant extracts was investigated in vitro. Totally 70 % of the plant extracts showed antifungal activity against Ustilago tritici and Ustilago nuda. Coridothyme extracts ranked first (61 %) in the fungal growth inhibition, followed by varthemia, salvia, ambrosia, artemisia, and lemon thyme. Some plant extracts significantly increased the POX and PPO effect compared to control for all the wheat and barley cultivars tested. The study revealed that oregano, clove or lavender and pomegranate, common yarrow or chamomile oil effectively induced the resistance indicator enzymes in wheat and barley.


2020 ◽  
Vol 104 (20) ◽  
pp. 8911-8924
Author(s):  
Hoang N. H. Tran ◽  
Lee Graham ◽  
Emmanuel C. Adukwu

Abstract Candida infections are a significant source of patient morbidity and mortality. Candida albicans is the most common pathogen causing Candida infections. Candida auris is a newly described pathogen that is associated with multi-drug-resistant candidiasis and candidaemia in humans. The antifungal effects of various essential oils and plant compounds have been demonstrated against human pathogenic fungi. In this study, the effect of cinnamon leaf and bark essential oils (CEOs) was determined against both C. albicans and C. auris. The disc diffusion (direct and vapour) and broth microdilution method was used to determine antifungal activity of the EOs against selected strains (C. albicans ATCC 10231, C. albicans ATCC 2091 and C. auris NCPF 8971) whilst the mode of action and haemolysin activity of the CEOs were determined using electron microscopy and light microscopy. Direct and vapour diffusion assays showed greater inhibitory activity of bark CEO in comparison with leaf CEO. The minimum inhibitory concentrations (MICs) and minimum fungicidal concentrations (MFCs) of bark CEO for all tested strains was below 0.03% (v/v), which was lower than the MICs of the leaf CEO (0.06–0.13%, v/v) dependent on the strain and the MFCs at 0.25% (v/v). In the morphological interference assays, damage to the cell membrane was observed and both CEOs inhibited hyphae formation. The haemolysin production assay showed that CEOs can reduce the haemolytic activity in the tested C. albicans and C. auris strains. At low concentrations, CEOs have potent antifungal and antihaemolytic activities in vitro against C. albicans and C. auris. Key points • Essential oils from Cinnamomum zeylanicum Blume bark and leaf (CBEO and CLEO) demonstrated fungicidal properties at very low concentrations. • The antifungal activity of CBEO was greater than that of CLEO consistent with other recent published literature. • The mode of action of CBEO and CLEO was damage to the membrane of C. albicans and C. auris. • Both CBEO and CLEO inhibited the formation of hyphae and reduced haemolysin production in C. albicans and C. auris.


2017 ◽  
Vol 32 (2) ◽  
pp. 121-127
Author(s):  
Mira Starovic ◽  
Danijela Ristic ◽  
Goran Aleksic ◽  
Snezana Pavlovic ◽  
Mehmet Özcan ◽  
...  

Development of natural plant protection products as an alternative to synthetic fungicides is of significant importance regarding the environment. This study was carried out with an objective to investigate in vitro antifungal activities of several essential oils extracted from oregano, basil, myrtle and Turkish pickling herb, and the plant growth-promoting rhizobacteria in the genus Pseudomonas, against the phytopathogenic fungus Phomopsis theicola. Microdilution methods were used to determine the minimum inhibitory concentrations (MIC) of selected antimicrobial essential oils (EOs). All EOs exhibited significant levels of antifungal activity against the tested fungal isolates. The oregano EO was found the most potent one (MIC - 5.5 ?g/mL), followed by basil (MIC - 75.0?g/mL), myrtle (MIC - 775 ?g/mL) and Turkish pickling herb (MIC - 7750 ?g/mL). Inhibition of Ph. theicola mycelial growth was observed for all tested Pseudomonas spp. strains. K113 and L1 strains were highly effective and achieved more than 60% of fungal growth inhibition using the overnight culture and more than 57% inhibition by applying cell-free supernatants of both strains. A future field trial with K113 and L1 cultures and cell-free supernatants, containing extracellular metabolites toward Ph. theicola, will estimate their effectiveness and applicability as an alternative to chemical protection of apple trees.


2020 ◽  
Vol 19 (1) ◽  
pp. 34-42
Author(s):  
Phanin Sintawarak ◽  
◽  
Suwimon Uthairatsamee ◽  
Tharnrat Keawgrajang ◽  
◽  
...  

Cylindrocladium reteaudii (Bugnic.) Boesew. is a severe pathogen which can cause leaf blight disease in Eucalyptus seedlings in tropical countries. This study investigated the antifungal activity of essential oils extracted from Acorus calamus L. rhizomes in inhibiting the growth of C. reteaudii, both in in vitro and in vivo experiments. The extraction of essential oils from rhizomes was carried out by hydro-distillation technique and the in vitro antifungal testing was done by using the poisoned food technique. The results indicated that an essential oil concentration of 2,000 ppm can completely inhibit the fungal growth with a 50% inhibitory concentration value of 54.76 ppm. For the in vivo experiment, it was found that an essential oil concentration of 500 ppm and Captan® of 1,000 ppm were not significantly different in inhibiting the growth of C. reteaudii. However, these two treatments significantly inhibited the fungal growth (p<0.05) when compared with the control treatments. Physiological and anatomical characteristics were investigated to check for the antifungal activity after the application of essential oils. Results showed that essential oil spraying had no effect on the leaf transpiration rate and temperature of the Eucalyptus seedlings, but the incident disease ratio was high when an essential oil concentration of more than 1,500 ppm was applied. Therefore, it can be inferred that the essential oils from A. calamus rhizomes at an optimum concentration can be an efficient antifungal compound with a potential to control leaf and shoot blight diseases in Eucalyptus seedlings in a nursery.


1994 ◽  
Vol 21 (2) ◽  
pp. 130-134 ◽  
Author(s):  
S. M. Basha ◽  
R. J. Cole ◽  
S. K. Pancholy

Abstract An in vitro seed culture system was established to grow peanut seed of different maturities viz. white, yellow, orange, brown and black, using a modified Murashige and Skoog medium. Under this system peanut seed of yellow, orange, brown and black maturity categories grew to maturity as measured by increase in their size and germinability. In vitro cultured seeds produced significant amounts of phytoalexins and were contaminated with aflatoxins following their inoculation with Aspergillus spp. while the noninoculated sterile controls did not produce any phytoalexins. Exposure of seed cultures to water stress using various concentrations of mannitol (0 to 1 M) and polyethylene glycol 8000 (0-30% w/v) caused a significant decrease in their phytoalexin producing ability, and enhanced fungal growth compared to the nonstressed controls. The seeds that were stressed with mannitol and subsequently inoculated with A. flavus and A. parasiticus showed a significant increase in the aflatoxin contamination of stressed seed compared to the unstressed control. This would indicate that in vitro grown seeds responded to water stress similar to the field grown peanuts by loosing their ability to produce phytoalexins and increased susceptibility to aflatoxin contamination. Hence, this system has a potential application in evaluating peanut genotypes for aflatoxin resistance under water stress.


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