RESUMO
BACKGROUND: Flavokawain B is one of the naturally occurring chalcones in the kava plant (Piper methysticum). It exhibits anticancer, anti-inflammatory and antimalarial properties. Due to its therapeutic potential, flavokawain B holds promise for the treatment of many diseases. However, due to its poor bioavailability and low aqueous solubility, its application remains limited. The attachment of a sugar unit impacts the stability and solubility of flavonoids and often determines their bioavailability and bioactivity. Biotransformation is an environmentally friendly way to improve the properties of compounds, for example, to increase their hydrophilicity and thus affect their bioavailability. Recent studies proved that entomopathogenic filamentous fungi from the genera Isaria and Beauveria can perform O-methylglycosylation of hydroxyflavonoids or O-demethylation and hydroxylation of selected chalcones and flavones. RESULTS: In the present study, we examined the ability of entomopathogenic filamentous fungal strains of Beauveria bassiana, Beauveria caledonica, Isaria farinosa, Isaria fumosorosea, and Isaria tenuipes to transform flavokawain B into its glycosylated derivatives. The main process occurring during the reaction is O-demethylation and/or hydroxylation followed by 4-O-methylglycosylation. The substrate used was characterized by low susceptibility to transformations compared to our previously described transformations of flavones and chalcones in the cultures of the tested strains. However, in the culture of the B. bassiana KCh J1.5 and BBT, Metarhizium robertsii MU4, and I. tenuipes MU35, the expected methylglycosides were obtained with high yields. Cheminformatic analyses indicated altered physicochemical and pharmacokinetic properties in the derivatives compared to flavokawain B. Pharmacological predictions suggested potential anticarcinogenic activity, caspase 3 stimulation, and antileishmanial effects. CONCLUSIONS: In summary, the study provided valuable insights into the enzymatic transformations of flavokawain B by entomopathogenic filamentous fungi, elucidating the structural modifications and predicting potential pharmacological activities of the obtained derivatives. The findings contribute to the understanding of the biocatalytic capabilities of these microbial cultures and the potential therapeutic applications of the modified flavokawain B derivatives.
Assuntos
Chalconas , Flavonas , Flavonoides/metabolismo , Flavonas/metabolismo , BiotransformaçãoRESUMO
Quercetin is the most abundant flavonoid in food products, including berries, apples, cauliflower, tea, cabbage, nuts, onions, red wine and fruit juices. It exhibits various biological activities and is used for medical applications, such as treating allergic, inflammatory and metabolic disorders, ophthalmic and cardiovascular diseases, and arthritis. However, its low water solubility may limit quercetin's therapeutic potential. One method of increasing the solubility of active compounds is their coupling to polar molecules, such as sugars. The attachment of a glucose unit impacts the stability and solubility of flavonoids and often determines their bioavailability and bioactivity. Entomopathogenic fungi are biocatalysts well known for their ability to attach glucose and its 4-O-methyl derivative to bioactive compounds, including flavonoids. We investigated the ability of cultures of entomopathogenic fungi belonging to Beauveria, Isaria, Metapochonia, Lecanicillium and Metarhizium genera to biotransform quercetin. Three major glycosylation products were detected: (1), 7-O-ß-D-(4â³-O-methylglucopyranosyl)-quercetin, (2) 3-O-ß-D-(4â³-O-methylglucopyranosyl)-quercetin and (3) 3-O-ß-D-(glucopyranosyl)-quercetin. The results show evident variability of the biotransformation process, both between strains of the tested biocatalysts from different species and between strains of the same species. Pharmacokinetic and pharmacodynamic properties of the obtained compounds were predicted with the use of cheminformatics tools. The study showed that the obtained compounds may have applications as effective modulators of intestinal flora and may be stronger hepato-, cardio- and vasoprotectants and free radical scavengers than quercetin.
Assuntos
Hypocreales , Quercetina , Quercetina/farmacologia , Quercetina/metabolismo , Glicosilação , Flavonoides/farmacologia , Hypocreales/metabolismo , Antioxidantes/farmacologia , Antioxidantes/metabolismo , Fungos/metabolismoRESUMO
BACKGROUND: Decision-making skills are considered crucial life skills that condition proper social functioning within groups (i.e., support authentic leadership skills and increasing one's chances of success and wellbeing in life). Nonetheless, the number of scientific papers addressing the role of life skills in developing authentic leadership skills in public health students is limited. The aim of the present study was to develop a theoretical model to determine the role of selected life skills in developing authentic leadership skills in public health students. METHODS: The study was conducted from January 16 through February 28, 2018. In total, 653 students undertaking in-service training in Master's degree programs qualified for the study, and complete data sets were obtained from 329 students (response rate 50.38%). The data were collected by means of a paper questionnaire. Four research tools were used in the study: The Authentic Leadership Self-Assessment Questionnaire, The Moral Foundations Questionnaire, The General Self-Efficacy Scale, and The Youth Leadership Life Skills Development Scale. RESULTS: Two subgroups were identified among the public health students in the study: 1) the extra life skills training group (N = 113) and 2) the no extra life skills training group (N = 216). Both groups of study participants did not differ significantly in terms of age (M (SD): 25.0 (3.89) vs. 25.0 (3.66); t = 0.068, P = 0.946). On the other hand, clear differences were observed in the case of the respondents' participation in voluntary service. The respondents from the extra life skills training group declared participation in voluntary activities less frequently than the respondents from the second identified group (48.7 vs. 31.9%). CONCLUSIONS: A verified theoretical model showed that course aimed at strengthening authentic leadership competences should be modular, should focus on self-improvement and critical reflection, and should be spread over time to enable and encourage each participant to grow and flourish at their own pace.
Assuntos
Liderança , Estudantes de Saúde Pública , Adolescente , Atitude , Estudos Transversais , Humanos , PolôniaRESUMO
This study evaluated the ability of selected strains of Trichoderma viride, T. viridescens, and T. atroviride to inhibit mycelium growth and the biosynthesis of mycotoxins deoxynivalenol (DON), nivalenol (NIV), zearalenone (ZEN), α-(α-ZOL) and ß-zearalenol (ß-ZOL) by selected strains of Fusarium culmorum and F. cerealis. For this purpose, an in vitro experiment was carried out on solid substrates (PDA and rice). After 5 days of co-culture, it was found that all Trichoderma strains used in the experiment significantly inhibited the growth of Fusarium mycelium. Qualitative assessment of pathogen-antagonist interactions showed that Trichoderma colonized 75% to 100% of the medium surface (depending on the species and strain of the antagonist and the pathogen) and was also able to grow over the mycelium of the pathogen and sporulate. The rate of inhibition of Fusarium mycelium growth by Trichoderma ranged from approximately 24% to 66%. When Fusarium and Trichoderma were co-cultured on rice, Trichoderma strains were found to inhibit DON biosynthesis by about 73% to 98%, NIV by about 87% to 100%, and ZEN by about 12% to 100%, depending on the pathogen and antagonist strain. A glycosylated form of DON was detected in the co-culture of F. culmorum and Trichoderma, whereas it was absent in cultures of the pathogen alone, thus suggesting that Trichoderma is able to glycosylate DON. The results also suggest that a strain of T. viride is able to convert ZEN into its hydroxylated derivative, ß-ZOL.
Assuntos
Fusarium , Micotoxinas , Oryza , Trichoderma , Tricotecenos , Zearalenona , Zearalenona/farmacologiaRESUMO
Fusarium species are common plant pathogens that cause several important diseases. They produce a wide range of secondary metabolites, among which mycotoxins and extracellular cell wall-degrading enzymes (CWDEs) contribute to weakening and invading the host plant successfully. Two species of Fusarium isolated from peas were monitored for their expression profile of three cell wall-degrading enzyme coding genes upon culturing with extracts from resistant (Sokolik) and susceptible (Santana) pea cultivars. The extracts from Santana induced a sudden increase in the gene expression, whereas Sokolik elicited a reduced expression. The coherent observation was that the biochemical profile of the host plant plays a major role in regulating the fungal gene expression. In order to uncover the fungal characteristics in planta, both pea cultivars were infected with two strains each of F. proliferatum and F. oxysporum on the 30th day of growth. The enzyme activity assays from both roots and rhizosphere indicated that more enzymes were used for degrading the cell wall of the resistant host compared to the susceptible host. The most commonly produced enzymes were cellulase, ß-glucosidase, xylanase, pectinase and lipase, where the pathogen selectively degraded the components of both the primary and secondary cell walls. The levels of beauvericin accumulated in the infected roots of both cultivars were also monitored. There was a difference between the levels of beauvericin accumulated in both the cultivars, where the susceptible cultivar had more beauvericin than the resistant one, showing that the plants susceptible to the pathogen were also susceptible to the toxin accumulation.
Assuntos
Fusarium/patogenicidade , Micotoxinas/genética , Pisum sativum/microbiologia , Doenças das Plantas/genética , Fusarium/genética , Interações Hospedeiro-Patógeno/genética , Pisum sativum/enzimologia , Doenças das Plantas/microbiologia , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/microbiologiaRESUMO
OBJECTIVES: A rare case of a suicidal use of gases from the car exhaust system of the car petrol engine in an open space is presented. CLINICAL PRESENTATION AND INTERVENTION: To verify suicidal intent of poisoning, an experimental reconstruction of the crime scene was performed. This demonstrated that appropriately long exposure to carbon monoxide with unfavorable weather conditions can cause acute carbon monoxide poisoning in an open space. CONCLUSIONS: This case was studied to observe the pattern of fatal carbon monoxide poisoning in an open space. This might be helpful for forensic medicine, emergency medicine, and occupational medicine.
Assuntos
Intoxicação por Monóxido de Carbono/diagnóstico , Suicídio , Autopsia , Medicina Legal , Humanos , Masculino , Pessoa de Meia-Idade , Veículos AutomotoresRESUMO
BACKGROUND: Steroid compounds are very interesting substrates for biotransformation due to their high biological activity and a high number of inactivated carbons which make chemical modification difficult. Microbial transformation can involve reactions which are complicated and uneconomical in chemical synthesis, and searching for a new effective biocatalyst is necessary. The best known entomopathogenic species used in steroid modification is Beauveria bassiana. In this study we tested the ability of Isaria farinosa, another entomopathogenic species, to transform several steroids. RESULTS: Twelve strains of the entomopathogenic filamentous fungus Isaria farinosa, collected in abandoned mines located in the area of the Lower Silesian Voivodeship, Poland, from insects' bodies covered by fungus, were used as a biocatalyst. All the tested strains effectively transformed dehydroepiandrosterone (DHEA). We observed 7α- and 7ß-hydroxy derivatives as well as changes in the percentage composition of the emerging products. Due to the similar metabolism of DHEA in all tested strains, one of them was selected for further investigation. In the culture of the selected strain, Isaria farinosa KCh KW1.1, transformations of androstenediol, androstenedione, adrenosterone, 17α-methyltestosterone, 17ß-hydroxyandrost-1,4,6-triene-3-one and progesterone were performed. All the substrates were hydroxylated with high yield and stereoselectivity. We obtained 6ß-hydroxyandrost-4-ene-3,11,17-trione, 15α,17ß-dihydroxy-6ß,7ß-epoxyandrost-1,4-diene-3-one and 6ß,11α-dihydroxyprogesterone. There is no evidence of either earlier microbial transformation of 17ß-hydroxyandrost-1,4,6-triene-3-one or new epoxy derivatives. CONCLUSIONS: Isaria farinosa has a broad spectrum of highly effective steroid hydroxylases. The obtained 7-hydroxydehydroepiandrosterone has proven high biological activity and can be used in Alzheimer's disease and as a key intermediate in the synthesis of aldosterone antagonists. Transformation of progesterone leads to high yield of 6ß,11α-dihydroxyprogesterone and it is worth further study.
Assuntos
Biotransformação/fisiologia , Desidroepiandrosterona/metabolismo , Proteínas Fúngicas/química , Progesterona/metabolismo , Esteroides/metabolismoRESUMO
Durum wheat (Triticum turgidum var. durum) is an important crop in Europe, particularly in the Mediterranean countries. Fusarium head blight (FHB) is considered as one of the most damaging diseases, resulting in yield and quality reduction as well as contamination of grain with mycotoxins. Three winter durum wheat cultivars originating from Austria, Slovakia, and Poland were analyzed during 2012-2014 seasons for FHB incidence and Fusarium mycotoxin accumulation in harvested grain. Moreover, the effects of sowing density and delayed sowing date were evaluated in the climatic conditions of Southern Poland. Low disease severity was observed in 2011/2012 in all durum wheat cultivars analyzed, and high FHB occurrence was recorded in 2012/2013 and 2013/2014 seasons. Fusarium graminearum was the most abundant pathogen, followed by Fusarium avenaceum. Through all three seasons, cultivar Komnata was the most susceptible to FHB and to mycotoxin accumulation, while cultivars Auradur and IS Pentadur showed less symptoms. High susceptibility of cv. Komnata was reflected by the number of Fusarium isolates and elevated mycotoxin (deoxynivalenol, zearalenone, and moniliformin) content in the grain of this cultivar across all three seasons. Nivalenol was identified in the samples of cv. Komnata only. Genotype-dependent differences in FHB susceptibility were observed for the plants sown at optimal date but not at delayed sowing date. It can be hypothesized that cultivars bred in Austria and Slovakia show less susceptibility towards FHB than the cultivar from Poland because of the environmental conditions allowing for more efficient selection of breeding materials.
Assuntos
Fusarium/fisiologia , Micotoxinas/análise , Triticum/química , Região do Mediterrâneo , Micotoxinas/metabolismo , Especificidade da Espécie , Fatores de Tempo , Triticum/metabolismoRESUMO
Fusarium proliferatum is a world-wide occurring fungal pathogen affecting several crops included garlic bulbs. In Spain, this is the most frequent pathogenic fungus associated with garlic rot during storage. Moreover, F. proliferatum is an important mycotoxigenic species, producing a broad range of toxins, which may pose a risk for food safety. The aim of this study is to assess the intraspecific variability of the garlic pathogen in Spain implied by analyses of translation elongation factor (tef-1α) and FUM1 gene sequences as well as the differences in growth rates. Phylogenetic characterization has been complemented with the characterization of mating type alleles as well as the species potential as a toxin producer. Phylogenetic trees based on the sequence of the translation elongation factor and FUM1 genes from seventy nine isolates from garlic revealed a considerable intraspecific variability as well as high level of diversity in growth speed. Based on the MAT alleles amplified by PCR, F. proliferatum isolates were separated into different groups on both trees. All isolates collected from garlic in Spain proved to be fumonisin B1, B2, and B3 producers. Quantitative analyses of fumonisins, beauvericin and moniliformin (common secondary metabolites of F. proliferatum) showed no correlation with phylogenetic analysis neither mycelial growth. This pathogen presents a high intraspecific variability within the same geographical region and host, which is necessary to be considered in the management of the disease.
Assuntos
Fusarium/genética , Fusarium/isolamento & purificação , Alho/microbiologia , Micotoxinas/metabolismo , Doenças das Plantas/microbiologia , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Fusarium/metabolismo , Variação Genética , Filogenia , EspanhaRESUMO
Asparagus officinalis L. is an important crop in many European countries, likely infected by a number of Fusarium species. Most of them produce mycotoxins in plant tissues, thus affecting the physiology of the host plant. However, there is lack of information on Fusarium communities in wild asparagus, where they would definitely have considerable environmental significance. Therefore, the main scientific aim of this study was to identify the Fusarium species and quantify their typical mycotoxins present in wild asparagus plants collected at four time points of the season. Forty-four Fusarium strains of eight species--Fusarium acuminatum, Fusarium avenaceum, Fusarium culmorum, Fusarium equiseti, Fusarium oxysporum, Fusarium proliferatum, Fusarium sporotrichioides, and Fusarium tricinctum--were isolated from nine wild asparagus plants in 2013 season. It is the first report of F. sporotrichioides isolated from this particular host. Fumonisin B1 was the most abundant mycotoxin, and the highest concentrations of fumonisins B1-B3 and beauvericin were found in the spears collected in May. Moniliformin and enniatins were quantified at lower concentrations. Mycotoxins synthesized by individual strains obtained from infected asparagus tissues were assessed using in vitro cultures on sterile rice grain. Most of the F. sporotrichioides strains synthesized HT-2 toxin and F. equiseti strains were found to be effective zearalenone producers.
Assuntos
Asparagus/metabolismo , Asparagus/microbiologia , Fusarium/fisiologia , Micotoxinas/biossíntese , Doenças das Plantas/microbiologia , DNA Fúngico/análise , DNA Fúngico/genética , Contaminação de Alimentos/análise , Microbiologia de Alimentos , Fusariose/metabolismo , Fusariose/microbiologia , Fusariose/patologia , Fusarium/genética , Fusarium/crescimento & desenvolvimento , Fusarium/isolamento & purificação , Interações Hospedeiro-Patógeno , Micotoxinas/análise , Micotoxinas/metabolismo , Micotoxinas/toxicidadeRESUMO
The present study examined Polish strains of Flamulina velutipes as a potential source of nutraceuticals and found that their nutritional value is dependent on the fruiting bodies gathering time. To prove the above hypothesis protein, carbohydrate and phenolic substances concentration were determined. Moreover, catalase, superoxide dismutase, cellobiose dehydrogenase activities were assayed. In order to prove the healing properties of Enoki fruiting bodies the obtained extracts were tested for antioxidant and bacteriostatic abilities. We have proved that Polish F. velutipes fruiting bodies may be a rich source of antioxidants and that they are capable of inhibiting Staphylococcus aureus growth.
Assuntos
Flammulina/química , Carpóforos/química , Antioxidantes/análise , Antioxidantes/metabolismo , Catalase/análise , Catalase/metabolismo , Flammulina/genética , Flammulina/isolamento & purificação , Flammulina/metabolismo , Carpóforos/metabolismo , Proteínas Fúngicas/metabolismo , Polônia , Superóxido Dismutase/análise , Superóxido Dismutase/metabolismoRESUMO
AIM: The aim of the study was to determine the factors influencing women's knowledge concerning breast cancer prophylaxis and find out the sources of the knowledge. BACKGROUND: In the Greater Poland region, breast cancer has been the most frequently detected tumour for years. The percentage of breast cancer cases has increased by 31% in the last decade. MATERIALS AND METHODS: The study encompassed 337 women aged 40-59 who participated in the mammographic examinations. An original research tool was used which assessed the level of knowledge concerning breast cancer prophylaxis, the knowledge of health-oriented behaviour in this regard and the influence of the medical personnel on women's education. RESULTS: Age is a factor diversifying the knowledge of the breast self-examination method. Doctors and nurses were rarely indicated as a source of knowledge concerning breast cancer prophylaxis. The subjects presented a high level of knowledge of the factors increasing the risk of developing cancer. CONCLUSIONS: A correlation between the level of education and the knowledge of one's own breast to a degree which enables a woman to detect even a slight change was observed. Vital findings also concern the sources of knowledge concerning breast cancer prophylaxis. The results of the studies indicated little informative support on the part of the medical personnel; therefore, one should call for supplementing training courses for doctors and nurses focusing on the issues of prophylaxis, including the method of breast self-examination.
RESUMO
Fusarium culmorum is a major wheat pathogen, and its secondary metabolites (mycotoxins) cause damage to plants, animals, and human health. In the era of sustainable agriculture, eco-friendly methods of prevention and control are constantly needed. The use of plant extracts as biocontrol agents has gained popularity as they are a source of active substances that play a crucial role in fighting against phytopathogens. This study evaluated the impact of Lamium album on wheat seed germination and seedling growth. In a pot experiment, the effect of L. album on wheat seedlings artificially inoculated with F. culmorum was evaluated by measuring seedling growth parameters, and by using chromatographic methods, ergosterol and mycotoxins levels were analyzed. The results showed that the phytotoxic effect of L. album flower extracts on wheat seed germination and seedling growth was concentration dependent. The radicle length was also reduced compared to the control; however, L. album did not significantly affect the dry weight of the radicle. A slight phytotoxic effect on seed germination was observed, but antifungal effects on artificially infected wheat seedlings were also confirmed with the reduction of ergosterol level and mycotoxins accumulation in the roots and leaves after 21 days of inoculation. F. culmorum DNA was identified in the control samples only. Overall, this study is a successful in planta study showing L. album flower extract protection of wheat against the pathogen responsible for Fusarium crown and root rot. Further research is essential to study the effects of L. album extracts on key regulatory genes for mycotoxin biosynthetic pathways.
RESUMO
The diversity of fungal strains is influenced by genetic and environmental factors, growth conditions and mycelium age, and the spectral features of fungal mycelia are associated with their biochemical, physiological, and structural traits. This study investigates whether intraspecific differences can be detected in two closely related entomopathogenic species, namely Cordyceps farinosa and Cordyceps fumosorosea, using ultraviolet A to shortwave infrared (UVA-SWIR) reflectance spectra. Phylogenetic analysis of all strains revealed a high degree of uniformity among the populations of both species. The characteristics resulting from variation in the species, as well as those resulting from the age of the cultures were determined. We cultured fungi on PDA medium and measured the reflectance of mycelia in the 350-2500 nm range after 10 and 17 days. We subjected the measurements to quadratic discriminant analysis (QDA) to identify the minimum number of bands containing meaningful information. We found that when the age of the fungal culture was known, species represented by a group of different strains could be distinguished with no more than 3-4 wavelengths, compared to 7-8 wavelengths when the age of the culture was unknown. At least 6-8 bands were required to distinguish cultures of a known species among different age groups. Distinguishing all strains within a species was more demanding: at least 10 bands were required for C. fumosorosea and 21 bands for C. farinosa. In conclusion, fungal differentiation using point reflectance spectroscopy gives reliable results when intraspecific and age variations are taken into account.
Assuntos
Luz , Micélio , Análise Discriminante , Filogenia , Análise Espectral/métodosRESUMO
The present study assessed the ability of Trichoderma to combat F. sporotrichioides, focusing on their antagonistic properties. Tests showed that Trichoderma effectively inhibited F. sporotrichioides mycelial growth, particularly with T. atroviride strains. In co-cultures on rice grains, Trichoderma almost completely reduced the biosynthesis of T-2 and HT-2 toxins by Fusarium. T-2 toxin-α-glucoside (T-2-3α-G), HT-2 toxin-α-glucoside (HT-2-3α-G), and HT-2 toxin-ß-glucoside (HT-2-3ß-G) were observed in the common culture medium, while these substances were not present in the control medium. The study also revealed unique metabolites and varying metabolomic profiles in joint cultures of Trichoderma and Fusarium, suggesting complex interactions. This research offers insights into the processes of biocontrol by Trichoderma, highlighting its potential as a sustainable solution for managing cereal plant pathogens and ensuring food safety.
Assuntos
Fusarium , Toxina T-2 , Toxina T-2/análogos & derivados , Trichoderma , Toxina T-2/metabolismo , Fusarium/metabolismo , Trichoderma/metabolismo , Glicosilação , Grão Comestível/metabolismo , Glucosídeos/metabolismoRESUMO
Sales and distribution of medical products and drugs in Poland remains under strict regulations, especially legal regulation contained in the Medical and Dental Practitioners Act, that banned sales of medical products by doctors. It needs to be emphasized that currently doctors are allowed to sell drugs and medical products only in rigorously specified situations. Knowledge of current legal regulations concerning sales of medical products by gynecologists allows to conform with the law and to distribute drugs and medical products under special and predefined conditions.
Assuntos
Competência Clínica/legislação & jurisprudência , Comércio/legislação & jurisprudência , Ginecologia/legislação & jurisprudência , Política de Saúde/legislação & jurisprudência , Relações Médico-Paciente , Padrões de Prática Médica/legislação & jurisprudência , Atitude do Pessoal de Saúde , Feminino , Regulamentação Governamental , Guias como Assunto , Humanos , Segurança do Paciente/legislação & jurisprudência , Polônia , Má Conduta Profissional/legislação & jurisprudência , Saúde da Mulher/legislação & jurisprudênciaRESUMO
Lamium album is a medicinal flowering plant that is rich in bioactive compounds with various biological properties. Fusarium species, known for causing significant crop losses and mycotoxin contamination, pose threats to food safety and human health. While synthetic fungicides are commonly employed for fungal management, their environmental impact prompts the ongoing development of alternative methods. This study aimed to evaluate the efficacy of L. album flower extracts in inhibiting the in vitro growth and biosynthesis of mycotoxins by Fusarium culmorum and F. proliferatum strains. The extracts were obtained by supercritical fluid extraction using CO2 (SC-CO2). The effects of various concentrations (2.5, 5, 7.5, and 10%) were assessed on a potato dextrose agar (PDA) medium using the "poisoning" technique. L. album flower extracts reduced mycelium growth by 0 to 30.59% for F. culmorum and 27.71 to 42.97% for F. proliferatum. Ergosterol content was reduced by up to 88.87% for F. culmorum and 93.17% for F. proliferatum. Similarly, the amounts of synthesized mycotoxins produced by both strains were also lower compared to control cultures. These findings are a preliminary phase for further in vivo tests planned to determine the fungistatic effect of L. album flower extracts on cereal substrates as seedlings incubated in controlled environments and under field conditions. Their phytotoxicity and biological stability, as well as the possibility of formulating a bio-preparation to protect cereals against Fusarium infections, will be evaluated.
Assuntos
Fungicidas Industriais , Fusarium , Micotoxinas , Humanos , Dióxido de Carbono , Micotoxinas/análise , Grão Comestível/química , Fungicidas Industriais/farmacologiaRESUMO
The objectives of this research were to obtain the extracts of lemon balm (Melissa officinalis) using supercritical CO2 (SC-CO2) and methanol as co-solvent and evaluate the antifungal activity of those extracts against two selected strains of Fusarium species (Fusarium culmorum and Fusarium proliferatum). The extraction conditions were set at 40 and 60 °C and 250 bar. The obtained extracts were characterized in terms of antifungal activity on potato dextrose agar media (PDA). The results showed that the extraction parameters had different effects on mycelium growth and mycotoxins biosynthesis reduction. All studied lemon balm extracts (1, 2.5, 5, 7.5, and 10%) inhibited the growth of F. proliferatum and F. culmorum mycelia compared to the control. The lemon balm extracts significantly reduced ergosterol content and synthesized mycotoxins in both tested strains. These findings support the antifungal activity of lemon balm extracts against F. proliferatum and F. culmorum. However, more research on other Fusarium species is needed, as well as in vivo applications, before considering lemon balm extracts as a natural alternative to synthetic fungicides.
Assuntos
Fusarium , Melissa , Micotoxinas , Antifúngicos/farmacologia , Dióxido de Carbono , Micotoxinas/farmacologia , Extratos Vegetais/farmacologiaRESUMO
Fusarium head blight (FHB) caused by pathogenic species of Fusarium fungi is one of the most important diseases of cereal plants and a factor contributing to losses in plant production. The growth of FHB-associated species is often accompanied by biosynthesis of secondary metabolitesâmycotoxins, which serve as a virulence factor. The aim of the study was to evaluate the ratios between deoxynivalenol (DON) and nivalenol (NIV) and their derivatives in the ears of six cultivars of winter wheat with varying resistance to FHB, taking into account a range of factors (weather conditions, location, cultivar, and year) after inoculation with Fusarium culmorum, during a 3 year field experiment, 2018-2020. The presence of toxins in the ears was measured within 21 days of inoculation. The toxins were found in the ears as soon as on the third day from the start of the experiment, whereas relative humidity higher than 80% was a decisive factor for FHB incidence. All wheat cultivars showed the ability to biotransform DON and NIV present in the ears to glucosides, that is, deoxynivalenol-3-glucoside (DON-3G) and nivalenol-3-glucoside (NIV-3G). The levels of these metabolites showed significant correlation with the levels of their basic analogues. In most cases, higher levels of DON and NIV in wheat ears and higher levels of their metabolites were observed, but the relative levels of DON-3G/DON and NIV-3G/NIV at relatively high levels of toxins were lower compared to the ear samples with relatively low toxin levels. The presented results are the first studies, which systematically correlate a variety of wheat cultivars with their extent to glucosylate trichothecenes.
Assuntos
Fusarium , Micotoxinas , Tricotecenos , Fusarium/metabolismo , Glucosídeos/metabolismo , Micotoxinas/metabolismo , Doenças das Plantas/microbiologia , Tricotecenos/metabolismo , Triticum/metabolismoRESUMO
Fusarium species present ubiquitously in the environment are capable of infecting a wide range of plant species. They produce several mycotoxins targeted to weaken the host plant. While infecting some resistant plants, the host can alter the expression of toxin-related genes and accumulate no/very low amounts of mycotoxins. The ability of the host plant to modulate the biosynthesis of these toxins is entirely depending on the secondary metabolites produced by the plant, often as a part of systemic acquired resistance (SAR). A major role plays in the family of metabolites called phenyl propanoids, consisting of thousands of natural products, synthesized from the phenylalanine or tyrosine amino acids through a cascade of enzymatic reactions. They are also famous for inhibiting or limiting infection through their antioxidant characteristics. The current study was aimed at identifying the differentially expressed secondary metabolites in resistant (Sokolik) and susceptible (Santana) cultivars of pea (Pisum sativum L.) and understanding their roles in the growth and mycotoxin biosynthesis of two different Fusarium species. Although metabolites such as coumarin, spermidine, p-coumaric acid, isoorientin, and quercetin reduced the growth of the pathogen, a higher level of p-coumaric acid was found to enhance the growth of F. proliferatum strain PEA1. It was also noticeable that the growth of the pathogen did not depend on their ability to produce mycotoxins, as all the metabolites were able to highly inhibit the biosynthesis of fumonisin B1 and beauvericin.