Enniatin B1 induces damage to Leydig cells via inhibition of the Nrf2/HO-1 and JAK/STAT3 signaling pathways.

Enniatin B1 (ENN B1) is a mycotoxin that can be found in various foods. However, whether ENN B1 is hazardous to the reproductive system is still elusive. Leydig cells are testosterone-generating cells that reside in the interstitial compartment between seminiferous tubules. Dysfunction of Leydig cells could result in male infertility. This study aimed to examine the toxicological effects of ENN B1 against TM3 Leydig cells. ENN B1 significantly inhibited cell viability in a dose-dependent manner. ENN B1 treatment also decreased the expression of functional genes in Leydig cells. Moreover, ENN B1 induced Leydig cells apoptosis and oxidative stress. Mechanistically, ENN B1 leads to the upregulation of Bax and downregulation of Bcl-2 in Leydig cells. In addition, ENN B1 inhibited the Nrf2/HO-1 pathway, which is critical for the induction of oxidative stress. Additionally, ENN B1 treatment repressed the JAK/STAT3 signaling pathway in Leydig cells. Rescue experiments showed that activation of STAT3 resulted in alleviation of ENN B1-induced damage in Leydig cells. Collectively, our study demonstrated that ENN B1 induced Leydig cell dysfunction via multiple mechanisms.

Complementary transcriptomic and proteomic analyses elucidate the toxicological molecular mechanisms of deoxynivalenol-induced contractile dysfunction in enteric smooth muscle cells.

Deoxynivalenol (DON) is one of the frequent Fusarium mycotoxins and poses a serious threat to public health worldwide. DON-induced weight loss is tightly connected with its ability to decrease feed intake by influencing gastrointestinal tract (GIT) motility. Our previous reports indicated that DON interfered with intestinal motility by injuring the contractility of enteric smooth muscle cells (SMC). Here, we further explored the potential mechanisms by employing a complementary method of transcriptomics and proteomics using the porcine enteric smooth muscle cell line (PISMC) as an experimental model. The transcriptomic and proteomic data uncover that the expression of numerous extracellular matrix (ECM) proteins and multiple integrin subunits were downregulated in PISMC under DON exposure, suppressing the ECM-integrin receptor interaction and its mediated signaling. Furthermore, DON treatment could depress actin polymerization, as reflected by the upregulated expression of Rho GTPase-activating proteins and cofilin in PISMC. Meanwhile, the expression levels of downstream contractile apparatus genes were significantly inhibited after challenge with DON. Taken together, the current results suggest that DON inhibits enteric SMC contractility by regulating the ECM-integrin-actin polymerization signaling pathway. Our findings provide novel insights into the potential mechanisms behind the DON toxicological effects in the GIT of humans and animals.

Undescribed α-pyrone-containing mycotoxins and an eremophilane-type sesquiterpenoid isolated from Aspergillus aureoterreus and their cytotoxicity.

Four previously undescribed and highly oxygenated α-pyrone-containing mycotoxins designated citreoviridins (E‒H), and an unreported eremophilane-type sesquiterpenoid namely aureoterrolide N, were isolated from the culture broth of Aspergillus aureoterreus. Those isolates were inferred from extensive spectroscopic methods and theoretical computation, where their absolute configurations were unambiguously determined by coupling constants following an empirical rule for the acyclic vicinal diol, theoretical ECD calculation, and NMR computation using the GIAO method and DP4+ analysis. Among them, citreoviridins E‒H are four stereoisomers of a citreoviridin derivative, featuring a methylated α-pyrone, an oxidized polyene linker, and a tetrahydrofuran ring. Cytotoxicity assay of all isolates demonstrated that aureoterrolide N exhibited weak inhibitory effect against human cancer cell line HL-60 with an inhibition rate of 55.2% at 40.0 µM.

Potential of utilizing pathogen-derived mycotoxins as alternatives to synthetic herbicides in controlling the noxious invasive plant Xanthium italicum.

Discovery of environmentally friendly agents for controlling alien invasive species (AIS) is challenging and in urgent need as their expansion continues to increase. Xanthium italicum is a notorious invasive weed that has caused serious ecological and economic impacts worldwide. For the purpose of exploring the possibility of utilizing herbicidal mycotoxins to control this species, three compounds, a new compound, curvularioxide (1), a new naturally occurring compound, dehydroradicinin (2), and a known compound, radicinin (3), were isolated via activity-guided fractionation from the secondary metabolites of the pathogenic Curvularia inaequalis, which was found to infect X. italicum in natural habitats. All isolated compounds exhibited potent herbicidal activity on receiver species. It is noteworthy to mention that their effects on X. italicum in our bioassays were equivalent to the commercial herbicide glyphosate. Subsequent morphological analysis revealed that application of radicinin (3) severely hindered X. italicum seedlings' hypocotyl and root development. Malondialdehyde content and the activity of catalase and peroxidase of the seedlings were also significantly different from the control, implying the occurrence of induced oxidative stress. Our results suggest that pathogens infecting invasive plants might be valuable resources for developing safer herbicides for controlling weeds. © 2023 Society of Chemical Industry.

Effect of novel botanical synergist on the effectiveness and residue behavior of prothioconazole in wheat field.

Fusarium head blight (FHB) is a critical fungal disease causes serious grain yield losses and mycotoxin contaminations. Currently, utilization of chemical fungicides is the main control method which has led to serious resistance. Development of novel synergist is an important strategy to reduce the usage of chemical fungicides and postpone the development of resistance, while natural components are interesting resources. In this study, the synergistic effect of Taxodium 'zhongshansha' essential oil (TZEO) was determined and the best synergistic ratio (SR) of 3.96 in laboratory which was observed when the weight ratio of TZEO and prothioconazole was 1 : 1 with the corresponding EC50 (half maximal effective concentration) value of Fusarium graminearum was 0.280 mg L-1. Subsequently, an increase of 6.31% on the control effect to FHB index in field test was observed when compared to the treatment with prothioconazole alone, though there was no significant difference between these treatments. Furthermore, we established an effective method to detect the mycotoxin contaminations in wheat grain with the limits of quantifications (LOQs) value of 5 µg kg-1 (DON, ZEN, 3-DON, and 15-DON) and 1 µg kg-1 (OTA) and the contents were less to the maximum residue limit (MRL) values. It was also shown that the application of 20% TZEO EW led to a 20% reduction in the use of prothioconazole, which was calculated based on the control effect values of 86.41% and 90.20% between the treatments of 30% prothioconazole OD (225 g a.i ha-1, recommend dosage) and 30% prothioconazole OD (180 g a.i ha-1) + 20% TZEO EW (225 mL ha-1), significantly. The initial residue of prothioconazole and prothioconazole-desthio was increased in the treatment with TZEO, which may play an important role in the synergistic effect on FHB. Moreover, none of the treatments posed a prothioconazole residue risk in the wheat grain and the environment. In addition, the essential oil has no any negative influence on wheat growth, which was revealed by a study of the chlorophyll content. These results provide an important botanical synergist for use with prothioconazole to control Fusarium head blight, and in-depth study to the synergistic mechanism of this oil is necessary in our future research.

Synergistic Effects of Essential Oils and Organic Acids against Aspergillus flavus Contamination in Poultry Feed.

Organic acids and essential oils are commonly used in the poultry industry as antimicrobials and for their beneficial effects on gut health, growth performance, and meat quality. A common postharvest storage fungal colonist, Aspergillus flavus, contaminates corn, the primary component of poultry feed, with the highly detrimental mycotoxin, aflatoxin. Aflatoxin adversely affects poultry feed intake, feed conversion efficiency, weight gain, egg production, fertility, hatchability, and poultry meat yield. Both organic acids and essential oils have been reported to inhibit the growth of A. flavus. Thus, we evaluated if the inhibitory synergy between combined essential oils (cinnamon, lemongrass, and oregano) and organic acids (acetic, butyric, and propionic) prevents A. flavus growth. The study confirmed that these compounds inhibit the growth of A. flavus and that synergistic interactions do occur between some of them. Overall, cinnamon oil was shown to have the highest synergy with all the organic acids tested, requiring 1000 µL/L air of cinnamon oil and 888 mg/kg of butyric acid to fully suppress A. flavus growth on corn kernels. With the strong synergism demonstrated, combining certain essential oils and organic acids offers a potentially effective natural method for controlling postharvest aflatoxin contamination in poultry feed.

Antifungal activity of Lysinibacillus macroides against toxigenic Aspergillus flavus and Fusarium proliferatum and analysis of its mycotoxin minimization potential.

BACKGROUND: Toxigenic fungi (Aspergillus and Fusarium) and their metabolites represent the major cause of corn and corn-based products contamination and consequently lead to severe economic and health issues. AIM: Our current study aimed to investigate the efficacy of using L. macroides Bac6 as a biological control agent against the toxigenic fungi; A. flavus f10 and F. proliferatum f30 and their mycotoxins. RESULTS: The results illustrated that A. flavus f10 produced the aflatoxins AFB1 and AFG2 with concentrations of 21.239 and 13.593 ppb, respectively. While F. proliferatum f30 produced fumonisin B1 (9600 ppb). Furthermore, L. macroides showed a high potential for inhibition of toxigenic fungal growth using a dual culture method. F. proliferatum f30 and A. flavus f10 were found to be inhibited by a percentage of 80 and 62.5%, respectively. The results were confirmed using the scanning electron microscope. The antagonistic bacteria, L. macroides, showed chitinase productivity and activity of 26.45 U/L and 0.12 U/mL/min, respectively, which illustrates its potential application as a biocontrol agent. The GC-MS analysis revealed an abundance of Pyrrolo[1,2-a] pyrazine-1,4-dione, Hexahydro in the bacterial supernatant that exhibited antifungal characteristics. L. macroides had a significant reduction of AFB1 and AFG2 produced by A. flavus f10, recording 99.25% and 99% inhibition, respectively. It also showed strong inhibition of fumonisin B1 (90% inhibition) produced by F. proliferatum f30. CONCLUSION: Thus, the current study is a prospective study evaluating for the first time the potential impact of L. macroides Bac6 against the toxigenic fungi and their toxins.

Low dose of zearalenone inhibited the proliferation of porcine prospermatogonia and transformed the physiology through cytokine-cytokine receptor interaction.

Zearalenone (ZEA) is a prevalent mycotoxin functions as an endocrine disrupter to the reproductive systems of farm animals, especially in pigs. To evaluate the effect and the underlying molecular changes that occurred when the porcine germline stem cells were exposed to ZEA, prospermatogonia (ProSGs) were enriched and treated with a gradient concentration (0-10 µM) of ZEA for 2-8 days. Our results showed that the ZEA treatment inhibited the proliferation of ProSGs in a dose-dependent manner with a critical concentration at 1 µM. Transcriptome analysis revealed that the differentially expressed genes mainly concentrated on the molecular function of positive regulation of response to stimulus, and the most enriching pathway is cytokine-cytokine receptor interaction. ZEA exposure decreased a buck of cytokine/chemokine expression involved in the inflammatory response and stem cells maintenance/self-renewal, moreover, some energy expenditure and anti-apoptosis genes were also down-regulated, while the up-regulated genes were mainly connected with the innate immunity. These data demonstrate that ZEA induces multiply cellular damage and may eventually do harm to the health and fertility of animals.

Phenamacril and carbendazim regulate trichothecene mycotoxin synthesis by affecting ROS levels in F. asiaticum.

Fusarium head blight caused by Fusarium asiaticum is an important cereal crop disease, and the trichothecene mycotoxins produced by F. asiaticum can contaminate wheat grain, which is very harmful to humans and animals. To effectively control FHB in large areas, the application of fungicides is the major strategy; however, the application of different types of fungicides has varying influences on the accumulation of trichothecene mycotoxins in F. asiaticum. In this study, phenamacril inhibited trichothecene mycotoxin accumulation in F. asiaticum; however, carbendazim (N-1H-benzimidazol-2-yl-carbamic acid, methyl ester) induced trichothecene mycotoxin accumulation. Additionally, phenamacril led to a lower level of reactive oxygen species (ROS) by inducing gene expression of the catalase and superoxide dismutase (SOD) pathways in F. asiaticum, whereas carbendazim stimulated ROS accumulation by inhibiting gene expression of the catalase and SOD pathways. Based on these results, we conclude that phenamacril and carbendazim regulate trichothecene mycotoxin synthesis by affecting ROS levels in F. asiaticum.

Effects of undesired substances and their bioaccumulation on the black soldier fly larvae, Hermetia illucens (Diptera: Stratiomyidae)-a literature review.

Black soldier fly (BSF), Hermetia illucens (L.) (Diptera: Stratiomyidae), is predominantly reared on organic wastes and other unused complementary substrates. However, BSF may have a buildup of undesired substances in their body. The contamination of undesired substance, e.g., heavy metals, mycotoxins, and pesticides, in BSF mainly occurred during the feeding process in the larval stage. Yet, the pattern of accumulated contaminants in the bodies of BSF larvae (BSFL) is varied distinctively depending on the diets as well as the contaminant types and concentrations. Heavy metals, including cadmium, copper, arsenic, and lead, were reported to have accumulated in BSFL. In most cases, the cadmium, arsenic, and lead concentration in BSFL exceeded the recommended standard for heavy metals occurring in feed and food. Following the results concerning the accumulation of the undesired substance in BSFL's body, they did not affect the biological parameters of BSFL, unless the amounts of heavy metals in their diets are highly exceeding their thresholds. Meanwhile, a study on the fate of pesticides and mycotoxins in BSFL indicates that no bioaccumulation was detected for any of the target substances. In addition, dioxins, PCBs, PAHs, and pharmaceuticals did not accumulate in BSFL in the few existing studies. However, future studies are needed to assess the long-term effects of the aforementioned undesired substances on the demographic traits of BSF and to develop appropriate waste management technology. Since the end products of BSFL that are contaminated pose a threat to both human and animal health, their nutrition and production process must be well managed to create end products with a low contamination level to achieve a closed food cycle of BSF as animal feed.

Deoxynivalenol Mycotoxin Inhibits Rabies Virus Replication In Vitro.

Rabies is a highly fatal disease, and it is vital to find effective ways to manage and control infection. There is a need for new effective antiviral drugs that are particularly effective treatments for rabies. Deoxynivalenol (DON) is known mainly for its toxicity, but at the molecular level, it can inhibit RNA and DNA replication, and there is increasing evidence that different doses of DON have a positive effect on inhibiting virus replication. Based on this, we evaluated the effect of DON on inhibiting the rabies virus in vitro. The inhibitory effect of DON on rabies virus activity was dose- and time-dependent, and 0.25 µg/mL of DON could inhibit 99% of rabies virus activity within 24 h. Furthermore, DON could inhibit the adsorption, entry, replication, and release of rabies virus but could not inactivate the virus. The inhibitory effect of DON on rabies virus may be achieved by promoting apoptosis. Our study provides a new perspective for the study of anti-rabies virus and expands the direction of action of mycotoxins.

The Effect of Environmental Factors on Mould Counts and AFB1 Toxin Production by Aspergillus flavus in Maize.

The toxins produced by Aspergillus flavus can significantly inhibit the use of maize. As a result of climate change, toxin production is a problem not only in tropical and subtropical areas but in an increasing number of European countries, including Hungary. The effect of meteorological factors and irrigation on mould colonization and aflatoxin B1 (AFB1) mycotoxin production by A. flavus were investigated in natural conditions, as well as the inoculation with a toxigenic isolate in a complex field experiment for three years. As a result of irrigation, the occurrence of fungi increased, and toxin production decreased. The mould count of fungi and toxin accumulation showed differences during the examined growing seasons. The highest AFB1 content was found in 2021. The main environmental factors in predicting mould count were temperature (Tavg, Tmax ≥ 30 °C, Tmax ≥ 32 °C, Tmax ≥ 35 °C) and atmospheric drought (RHmin ≤ 40%). Toxin production was determined by extremely high daily maximum temperatures (Tmax ≥ 35 °C). At natural contamination, the effect of Tmax ≥ 35 °C on AFB1 was maximal (r = 0.560-0.569) in the R4 stage. In the case of artificial inoculation, correlations with environmental factors were stronger (r = 0.665-0.834) during the R2-R6 stages.

Impact of Deoxynivalenol and Zearalenone as Single and Combined Treatment on DNA, Cell Cycle and Cell Proliferation in HepG2 Cells.

The study aimed to investigate toxicity and the mechanism of toxicity of two Fusarium mycotoxins, deoxynivalenol (DON) and zearalenone (ZEA). DON and ZEA were applied to HepG2 cells as single compounds and in combination at low environmentally relevant concentrations. HepG2 cells were exposed to DON (0.5, 1, and 2 µM), ZEA (5, 10, and 20 µM) or their combinations (1 µM DON + 5 µM ZEA, 1 µM DON + 10 µM ZEA and 1 µM DON + 20 µM ZEA) for 24 h and cell viability, DNA damage, cell cycle and proliferation were assessed. Both mycotoxins reduced cell viability, however, combined treatment with DON and ZEA resulted in higher reduction of cell viability. DON (1 µM) induced primary DNA damage, while DON (1 µM) in combination with higher ZEA concentrations showed antagonistic effects compared to DON alone at 1 µM. DON arrested HepG2 cells in G2 phase and significantly inhibited cell proliferation, while ZEA had no significant effect on cell cycle. The combined treatment with DON and ZEA arrested cells in G2 phase to a higher extend compared to treatment with single mycotoxins. Potentiating effect observed after DON and ZEA co-exposure at environmentally relevant concentrations indicates that in risk assessment and setting governments' regulations, mixtures of mycotoxins should be considered.

Pathogenic Drug Resistant Fungi: A Review of Mitigation Strategies.

Fungal pathogens cause significant human morbidity and mortality globally, where there is a propensity to infect vulnerable people such as the immunocompromised ones. There is increasing evidence of resistance to antifungal drugs, which has significant implications for cutaneous, invasive and bloodstream infections. The World Health Organization (WHO) published a priority list of fungal pathogens in October 2022, thus, highlighting that a crisis point has been reached where there is a pressing need to address the solutions. This review provides a timely insight into the challenges and implications on the topic of antifungal drug resistance along with discussing the effectiveness of established disease mitigation modalities and approaches. There is also a need to elucidate the cellular and molecular mechanisms of fungal resistance to inform effective solutions. The established fungal decontamination approaches are effective for medical device processing and sterilization, but the presence of pathogenic fungi in recalcitrant biofilms can lead to challenges, particularly during cleaning. Future design ideas for implantable and reusable medical devices should consider antifungal materials and appropriates for disinfection, and where it is relevant, sterilization. Preventing the growth of mycotoxin-producing fungi on foods through the use of appropriate end-to-end processes is advisable, as mycotoxins are recalcitrant and challenging to eliminate once they have formed.

Targeted Sphingolipid Analysis in Heart, Gizzard, and Breast Muscle in Chickens Reveals Possible New Target Organs of Fumonisins.

Alteration of sphingolipid synthesis is a key event in fumonisins toxicity, but only limited data have been reported regarding the effects of fumonisins on the sphingolipidome. Recent studies in chickens found that the changes in sphingolipids in liver, kidney, lung, and brain differed greatly. This study aimed to determine the effects of fumonisins on sphingolipids in heart, gizzard, and breast muscle in chickens fed 20.8 mg FB1 + FB2/kg for 9 days. A significant increase in the sphinganine:sphingosine ratio due to an increase in sphinganine was observed in heart and gizzard. Dihydroceramides and ceramides increased in the hearts of chickens fed fumonisins, but decreased in the gizzard. The dihydrosphingomyelin, sphingomyelin, and glycosylceramide concentrations paralleled those of ceramides, although the effects were less pronounced. In the heart, sphingolipids with fatty acid chain lengths of 20 to 26 carbons were more affected than those with 14-16 carbons; this difference was not observed in the gizzard. Partial least squares-discriminant analysis on sphingolipids in the heart allowed chickens to be divided into two distinct groups according to their diet. The same was the case for the gizzard. Pearson coefficients of correlation among all the sphingolipids assayed revealed strong positive correlations in the hearts of chickens fed fumonisins compared to chickens fed a control diet, as well as compared to gizzard, irrespective of the diet fed. By contrast, no effect of fumonisins was observed on sphingolipids in breast muscle.

In Vitro Effects of Enniatin A on Steroidogenesis and Proliferation of Bovine Granulosa Cells.

The emerging Fusarium mycotoxins enniatins (ENNs) have been the focus of new research because of their well-documented existence in various cereal and grain products. Research findings indicate that reproductive disorders may be caused by exposure to Fusarium mycotoxins, but little work has evaluated ENNs on reproductive function. Therefore, to determine the effects of ENNA on the proliferation and steroidogenesis of granulosa cells (GC), experiments were conducted using bovine GC cultures. In vitro, ENNA (1−5 µM) inhibited (p < 0.05) hormone-induced GC progesterone and estradiol production. The inhibitory effect of ENNA on estradiol production was more pronounced in small- than large-follicle GC. In large-follicle GC, 0.3 µM ENNA had no effect (p > 0.10) whereas 1 and 3 µM ENNA inhibited GC proliferation. In small-follicle GC, ENNA (1−5 µM) dramatically decreased (p < 0.05) GC proliferation. Using cell number data, the IC50 of ENNA was estimated at 2 µM for both follicle sizes. We conclude that ENNA can directly inhibit ovarian function in cattle, decreasing the proliferation and steroid production of GC.

Targeted sphingolipid analysis in chickens suggests different mechanisms of fumonisin toxicity in kidney, lung, and brain.

Most of the toxic effects of fumonisins can be related to sphingolipid alteration, but there is little sphingolipidomic data in animals fed fumonisins in organs other than the liver. This study aimed to measure fumonisin B1 (FB1) in kidney, lung, and brain and determine its effects on sphingolipids. Thirty chickens divided into three groups received a diet containing 20.8 mg FB1+FB2/kg for 0, 4, or 9 days. FB1 increased in kidney from 1.7 to 5.6 nmol/kg and in lung from 0.5 to 1 nmol/kg at 4 and 9 days, respectively. No FB1 was detected in brain. In kidney, sphinganine increased, C14-C16 ceramides decreased, whereas C18-C26 ceramides increased. Most of the changes in dihydroceramides, dihydrodeoxyceramides, deoxyceramides sphingomyelins, dihydrosphingomyelins, and hexosylceramides paralleled those on ceramides. In lung, sphinganine was unaffected by fumonisins, whereas sphinganine-1-phosphate increased. Other major changes corresponded to decreases in glycosylceramides. In brain, sphinganine was unchanged, whereas deoxysphinganine, sphingosine, C14-C20 ceramides, and C14-C20 sphingomyelins increased. These results revealed that alterations in sphingolipids in kidney were close to those measured in liver and could correspond to inhibition of ceramide synthase 5 activity. In contrast, effects of fumonisins in lung and brain cannot be explained by inhibition of ceramide synthase.

The escape of Candida albicans from macrophages is enabled by the fungal toxin candidalysin and two host cell death pathways.

The egress of Candida hyphae from macrophages facilitates immune evasion, but it also alerts macrophages to infection and triggers inflammation. To better define the mechanisms, here we develop an imaging assay to directly and dynamically quantify hyphal escape and correlate it to macrophage responses. The assay reveals that Candida escapes by using two pore-forming proteins to permeabilize macrophage membranes: the fungal toxin candidalysin and Nlrp3 inflammasome-activated Gasdermin D. Candidalysin plays a major role in escape, with Nlrp3 and Gasdermin D-dependent and -independent contributions. The inactivation of Nlrp3 does not reduce hyphal escape, and we identify ETosis via macrophage extracellular trap formation as an additional pathway facilitating hyphal escape. Suppressing hyphal escape does not reduce fungal loads, but it does reduce inflammatory activation. Our findings explain how Candida escapes from macrophages by using three strategies: permeabilizing macrophage membranes via candidalysin and engaging two host cell death pathways, Gasdermin D-mediated pyroptosis and ETosis.

Research progress in toxicological effects and mechanism of aflatoxin B1 toxin.

Fungal contamination of animal feed can severely affect the health of farm animals, and result in considerable economic losses. Certain filamentous fungi or molds produce toxic secondary metabolites known as mycotoxins, of which aflatoxins (AFTs) are considered the most critical dietary risk factor for both humans and animals. AFTs are ubiquitous in the environment, soil, and food crops, and aflatoxin B1(AFB1) has been identified by the World Health Organization (WHO) as one of the most potent natural group 1A carcinogen. We reviewed the literature on the toxic effects of AFB1 in humans and animals along with its toxicokinetic properties. The damage induced by AFB1 in cells and tissues is mainly achieved through cell cycle arrest and inhibition of cell proliferation, and the induction of apoptosis, oxidative stress, endoplasmic reticulum (ER) stress and autophagy. In addition, numerous coding genes and non-coding RNAs have been identified that regulate AFB1 toxicity. This review is a summary of the current research on the complexity of AFB1 toxicity, and provides insights into the molecular mechanisms as well as the phenotypic characteristics.

Lethal and Sublethal Toxicity Assessment of Cyclosporin C (a Fungal Toxin) against Plutella xylostella (L.).

Secondary metabolites/toxins produced by Purpeocillium lilacinum (Hypocreales; Phiocordycipitaceae), a well-known insect pathogen, can be used for the management of different insect pests. We report the lethal and sublethal effects of cyclosporin C (a toxin produced by P. lilacinum) against a major vegetable pest, Plutella xylostella, at specific organismal (feeding rate, larval growth, adult emergence, fecundity, and adult longevity) and sub-organismal levels (changes in antioxidant and neurophysiological enzyme activities). The toxicity of cyclosporin C against different larval instars of P. xylostella increased with increasing concentrations of the toxin and the maximum percent mortality rates for different P. xylostella larval instars at different times were observed for the 300 µg/mL cyclosporin C treatment, with an average mortality rate of 100% for all larval instars. The median lethal concentrations (LC50) of cyclosporin C against the first, second, third, and fourth larval instars of P. xylostella 72 h post-treatment were 78.05, 60.42, 50.83, and 83.05 µg/mL, respectively. Different concentrations of cyclosporin C caused a reduction in the average leaf consumption and average larval weight. Different life history parameters, such as the pupation rate (%), adult emergence (%), female fecundity, and female longevity were also inhibited when different concentrations of cyclosporin C were applied topically. The cyclosporin C concentrations inhibited the activities of different detoxifying (glutathione S-transferase, carboxylesterase, and acetylcholinesterase) and antioxidant enzyme (superoxide dismutase, catalase, and peroxidase) activities of P. xylostella when compared to the control. These findings can serve as baseline information for the development of cyclosporin C as an insect control agent, although further work on mass production, formulation, and field application is still required.