Toxin Research Articles

Design of a Duplex-to-Complex Structure-Switching Approach for the Homogeneous Determination of Marine Biotoxins in Water

In this report, we describe a fluorescent assay for the detection of six marine toxins in water. The mechanism of detection is based on a duplex-to-complex structure-switching approach. The six aptamers specific to the targeted cyanotoxins were conjugated to a fluorescent dye, carboxyfluorescein (FAM). In parallel, complementary DNA (cDNA) sequences specific to each aptamer were conjugated to a fluorescence quencher BHQ1. In the absence of the target, an aptamer–cDNA duplex structure is formed, and the fluorescence is quenched. By adding the toxin, the aptamer tends to bind to its target and releases the cDNA. The fluorescence intensity is consequently restored after the formation of the complex aptamer–toxin, where the fluorescence recovery is directly correlated with the analyte concentration. Based on this principle, a highly sensitive detection of the six marine toxins was achieved, with the limits of detection of 0.15, 0.06, 0.075, 0.027, 0.041, and 0.026 nM for microcystin-LR, anatoxin-α, saxitoxin, cylindrospermopsin, okadaic acid, and brevetoxin, respectively. Moreover, each aptameric assay showed a very good selectivity towards the other five marine toxins. Finally, the developed technique was applied for the detection of the six toxins in spiked water samples with excellent recoveries.

7Method for Detection of Naturally Occurring Toxins in Human Urine Using Liquid Chromatography High Resolution Mass Spectrometry.

Natural toxins present an ongoing risk for human exposure that requires a rapid, accurate diagnosis for proper response. In this study, a qualitative liquid chromatography high resolution mass spectrometry (LC-HRMS) method was developed and validated for the detection of a large, diverse selection of natural toxins. Data-dependent acquisition was performed to identify compounds with an in-house mass spectral library of 129 hazardous toxins that originate from plants, animals, and fungi. All 129 compounds were spiked into human urine, extracted, and evaluated for spectral library matching. Of these, 92 toxins met the quality criteria and underwent validation in urine matrix based on American National Standards Institute (ANSI) guidelines. A generalized workflow for method expansion was developed and enables the rapid addition of relevant compounds to the established method. This LC-HRMS method achieves efficient detection of natural toxins in urine, and the created workflow can rapidly increase compound coverage via method expansion.

Characterising okadaic acid (OA) toxicity both in vitro and in vivo, using a comparative porcine model (MOKAPIG).

Food toxicology helps to protect the health and safety of consumers by a better understanding of the impact of xenobiotics and natural toxins on public health. Professors Mauro Dacasto (UNIPD), Flavia Girolami (UNITU), and Anna Zaghini (UNIBO) have collaborated on a research assessing the impact of aflatoxin B1 (a harmful mycotoxin) on bovine and human health. In their current project, MOKAPIG, the researchers are using comparative human and pig in vitro models as well as the weaned pig as an animal model to shed a light on the fate of differing levels of okadaic acid (OA) in target tissues such as the gastrointestinal tract and the liver. The goal of the two-year project is to expand the existing knowledge on the effects of OA on humans and pigs, including data on OA toxicokinetics, toxicodynamics and mechanistic toxicology. This will help to improve the protection of consumer health and seafood safety. MOKAPIG will first assess OA cytotoxicity and its bioavailability in vitro, characterise and profile OA metabolism and carry out comparative toxicogenomic studies. Then, the project will explore the in vivo toxicity of OA using a porcine animal model. The reasoning behind selecting a porcine over a rodent model is that mice show limitations for the assessment of marine toxins comparative toxicity, e.g, species-differences in xenobiotic metabolism.

Specific anti-toxic immunotherapy: use in medical practice and perspectives

The results of use of approaches and means of antitoxic immunotherapy in medical practice are summarized: passive transfer of various variants of antibodies specific to toxic compounds, vaccination – specific active immunization with vaccines carrying determinants of the immunochemical specificity of target toxic compounds. The practical effectiveness of the known approaches of passive transfer and vaccination is associated with the ability of specific antibodies, by binding target bioactive compounds with pronounced toxicity, to change the availability of corresponding structures in the body-targets and, in the presence of a sufficient number of specific antibodies with high binding ability to the target compounds, neutralize their toxicity. In medical practice, polyspecific heterologous antisera or the gamma globulin fraction of antisera (extremely rare monoclonal antibodies of narrow specificity) are widely used for passive transfer as antidotes in the treatment of victims in order to prevent deaths and extensive necrosis of soft tissues at the site of the bite of poisonous snakes and insects. Active immunization – vaccination with appropriate antigenic drugs should create in immunized individuals a state of humoral immunity with the corresponding characteristics of antibody formation specific to the target compound. When a target toxic compound enters an immunized organism, it is also possible to neutralize its toxicity. The most successful experience in using the principles of active immunization as a technology for specific antitoxic therapy is associated with the practice of using toxoids for toxinemic infections. Specific practical techniques used to achieve the effectiveness of possible approaches to specific antitoxic immunotherapy in the form of passive transfer of specific antibodies or their fragments are considered: to combat lethal infections in the pathogenesis of which the toxic effects of bacterial exotoxins are significant; when treating victims of snake and insect bites, exposure to poisons of marine organisms, algae and plant toxins; in the treatment of severe intoxication with certain low molecular weight toxic substances: digoxin, colchicine, tricyclic antidepressants. The most successful experiences of using the principles of active immunization as a technology for specific antitoxic therapy, based on the use of toxoids with specificity for diphtheria, tetanus, botulism, cholera, typhoid fever, dysentery, gas gangrene and other toxinemic infections, are also considered. The fairly high immunogenicity of toxoids with the possibility of activating both constitutional and adaptive immunity has become the basis for their use as macromolecular carriers of hapten analogues of narcotic substances – a promising direction in drug addiction, in the implementation of which a number of experimental molecular and combined vaccines of opiates, methamphetamine, cocaine, and nicotine. This variant of practical efforts in medicine can be regarded as a new direction of specific antitoxic immunotherapy – an option to combat drug addiction by vaccinating drug addicts.

Green Poison : A Sustainable Approach to Use Plant Toxin as an Anticancer Agent

The rising interest in plant-derived phytochemicals as cancer therapies has revealed numerous bio-active compounds with potent therapeutic potential. Compounds like vinca alkaloids, taxane , and berberine exhibit diverse biological activities, including anti-tumor, proving effective against various cancer types. Despite the toxicity of some medicinal plants, this feature can be harnessed for drug discovery, offering new treatments for cancer. Plant metabolites target tumor growth by inhibiting tumor-promoting enzymes, repairing DNA, and boosting immune responses. Compounds like vinblastine disrupt micro-tubule dynamics, while curcumin inhibits cancer cell proliferation. Toxic plant-derived metabolites, such as podophyllotoxin and camptothecin, demonstrate unique cancer-fighting mechanisms by targeting topoisomerases and inducing apoptosis. Integrating these phytochemical promise for advancing cancer prevention and treatment, offering more sustainable and effective options.

(+) Anatoxin-a elicits differential survival, photolocomotor behavior, and gene expression in two alternative vertebrate models

Anatoxin-a is a globally occurring, yet understudied, chiral cyanobacterial toxin that threatens public health and the environment. It has led to numerous dog. livestock and bird poisonings and although it has been studied in rodent models, comparatively little research has occurred in aquatic species. To advance a comparative toxicology understanding of this toxin in alternative vertebrate models, developing zebrafish and fathead minnow were exposed to environmentally relevant and elevated levels (13–4400 μg/L) of (+) anatoxin-a to examine potential mortality and sublethal effects, including photolocomotor behavior and gene expression responses. We observed significantly higher mortality (p < 0.05) in fathead minnows exposed to ≥ 1400 μg/L (65 – 83 % survival versus 97 % in controls). Locomotor response profiles for zebrafish typically displayed hypoactivity after exposure to (+) anatoxin-a in both light and dark periods, while hyperactivity of fathead minnows was observed at the lowest treatment level, but only in light conditions. Gene expression in zebrafish was significantly (p < 0.05) downregulated for mbp, which is associated with myelin sheath formation, and elavl3, which is involved in neurogenesis, along with cyp3a65 and gst, two genes related to phase I and II metabolism. However, no significant (p > 0.05) transcriptional changes were observed in the fathead minnow model. These differential responses between commonly employed species employed as alternative vertebrate models in toxicology research and chemicals risk assessments highlight the need for more comparative studies to understand sensitivities and variations in organismal response. Furthermore, we identified higher mortality, refractory behavioral effects, and gene expression in (+) anatoxin-a exposed fish when compared to previously reported (±) anatoxin-a (racemic 50:50 enantiomer mixture) studies, which is frequently used as a surrogate chemical for experimental work. Our findings identify the importance of understanding species and enantiomer specific effects of natural toxins.

Effects of the harmful algal bloom toxin, okadaic acid, on the mechanoreceptors of larval anchoveta (Engraulis ringens) under varying environmental conditions

The effect of the combination of marine toxins produced by algal blooms, in conjunction with varying environmental characteristics on organisms in the water column, is a poorly explored research field. Pelagic fish species of commercial importance, such as anchoveta (Engraulis ringens) in central Chile, may be exposed to these combined factors in a climate change scenario. This is observed from documented changes in the length of the upwelling season, frequency of upwelling events, and the increased frequency of atmospheric rivers affecting the southern spawning zone of this species. This study evaluated the integrity of hair cells in neuromasts, mechanosensory organs present in fish larvae, under exposure to different combinations of the algal bloom-produced okadaic acid OA (1 ng mL−1), and two temperature (12 and 14°C), and salinity treatments (historically more frequent: 34 PSU- 12°C; expected: 32 PSU - 14°C). Viable hair cells were counted in newly hatched larvae from the Biobío region, central Chile. Results showed a significant decrease in the average number of viable hair cells per neuromast (from 6.1 ± 1.6 to 4.0 ± 1.2) under lower salinity treatments (32 PSU) compared to normal conditions. Additionally, a seasonal trend was observed with fewer viable cells (from 7.4 ± 1.2 to 4.4 ± 1.1) as the fish species’ reproductive period progressed. The combined effect of OA exposure and modifications with the environmental factors also resulted in a significant decrease of up to 70% in the number of viable hair cells in larvae exposed to OA and high temperatures, indicating damage influenced by the toxin along with a synergistic and/or additive role of temperature. These findings reveal how the lipophilic toxin okadaic acid, produced by harmful algal blooms, interacts with abiotic environmental factors affecting coastal ecologically and socio-economically important organisms. This emphasizes the need to consider multiple factors when studying the effects of marine toxins.

B-292 Detection of natural toxins derived from potatoes by biotin-streptavidin direct ELISA

Abstract Background α-solanine (SO) and α-chaconine (CHA) are natural toxins of potato and often cause food poisoning worldwide. We have previously developed a polyclonal antibody (anti-Sold antibody) that bind to SO and CHA and used it in an enzyme-linked immunosorbent assay (ELISA). Our previously constructed ELISA (conventional ELISA) has a weak point of low sensitivity in detecting SO and CHA, we have tried to improve it in this study. Methods Solanidine, a chemical compound found in both SO and CHA, was conjugated with bovine albumin, and this complex was repeatedly injected into two rabbits for two months. Anti-Sold antibody was then purified from rabbit serum using affinity column chromatography. In our ELISA method, named “B-S direct ELISA”, biotin-labeled anti-Sold antibody is bound to SO and CHA in the sample, followed by the binding of peroxidase-labeled streptavidin. To simulate biological samples from patients with potato food poisoning, SO and CHA powders were mixed with commercially available human serum and urine, and SO and CHA levels were then measured using ELISA. Lastly, SO and CHA levels were detected in extracts from rotten potato (Irish Cobbler) sprouts, peels, and tubers. Results The absorbance of the samples containing SO and CHA prepared in 10 mM phosphate buffer saline (PBS) was about 5-fold higher than that of the conventional ELISA. Furthermore, the absorbance of the samples containing SO and CHA prepared in human serum and urine was enhanced about 2.5- and 1.6-fold, respectively, compared to that of the conventional ELISA. The limit of detection in B-S direct ELISA was 0.32 ng/mL in 10 mM PBS, 2.08 ng/mL in serum, and 4.88 ng/mL in urine, respectively. Using this ELISA, it was also possible to measure the content of SO and CHA in extracts of potato tubers, peels, and sprouts. Both SO and CHA in the extracts from rotten potato tubers and peels were detected as approximately 1.4- and 2.2-fold higher, respectively, in each part than those in the extracts from fresh potatoes. Furthermore, the potato sprout extract contained approximately 50-fold more SO and CHA than the tuber and 9-fold more than the peel. On the other hand, B-S direct ELISA cross-reacted with solanidine and solasodine, which have similar chemical structures to SO and CHA, and also with cholesterol and vitamin D3 in serum. Conclusions Based on our results, B-S direct ELISA presented greater performance in detecting SO and CHA than our conventional ELISA. The non-specific reactions in the serum samples and influence of urea in the urine samples may underlie the reduced detection performance of SO and CHA in ELISA, respectively. Although this ELISA has a detection performance applicable to human biological samples, cross-reactivity should be fully considered when judging the results.

A Mechanistic Review on Protective Effects of Mangosteen and its Xanthones Against Hazardous Materials and Toxins.

Due to its pharmacological properties, α-Mangostin, mainly found in Garcinia mangostana (G. mangostana) L. (Mangosteen, queen of fruits), treats wounds, skin infections, and many other disorders. In fact, α-Mangostin and other xanthonoid, including β-Mangostin and γ-Mangostin, are found in G. mangostana, which have various advantages, namely neuroprotective, anti-proliferative, antinociceptive, antioxidant, pro-apoptotic, anti-obesity, anti-inflammatory, and hypoglycemic through multiple signaling mechanisms, for instance, extracellular signal-regulated kinase1/2 (ERK 1/2), mitogenactivated Protein kinase (MAPK), nuclear factor-kappa B (NF-kB), transforming growth factor beta1 (TGF-β1) and AMP-activated protein kinase (AMPK). This review presents comprehensive information on Mangosteen's pharmacological and antitoxic aspects and its xanthones against various natural and chemical toxins. Because of the insufficient clinical study, we hope the current research can benefit from performing clinical and preclinical studies against different toxic agents.

Temperature dependent sensitivity of the harpacticoid copepod Nitokra spinipes to marine algal toxins

Harmful algal blooms (HABs) – proliferated algae densities, often producing toxins – have increasingly been found in ocean and coastal areas. Recent studies show that rising temperatures contribute to HAB occurrence, but the broader influence of climate change on these outbreaks is less quantified. Of particular concern is the limited research on HAB toxin effects under varying temperatures, especially regarding primary consumers such as copepods, a crucial component of aquatic ecosystems. Therefore, we examined the impact of marine toxins on the harpacticoid copepod Nitokra spinipes, a model organism for marine ecotoxicology, in the context of climate change. We evaluated the toxicity of four purified, commonly occurring algal toxins, at three different temperatures in the laboratory. First, adult females were exposed to a concentration series of toxins at 15, 20, and 25 °C for 48 hours. EC50 values of domoic acid ranged from 8.79 ± 1.93 μg L-1 to 25.97 ± 11.96 μg L-1. Nauplii, aged 48 to 72 hours, were exposed at 18, 20 and 22 °C for the same duration. Less sensitive compared to adults, the EC50 of domoic acid in this case varied from 57.26 ± 6.82 μg L-1 to 97.24 ± 6.45 μg L-1. Both results indicated a temperature-dependent EC50. For the chronic toxicity tests, larval development ratio (LDR), brood size and inter-brood time of domoic acid (DA), yessotoxin (YTX), saxitoxin (STX), and microcystin-LR (MC-LR) were examined at 18, 20 and 22 °C. We observed that with increasing temperatures, LDR increased, whereas brood size significantly decreased as DA, YTX or STX concentrations rose. No interaction between temperature and algal toxins was found but a temperature dependent sensitivity of copepods towards DA, YTX and STX was revealed. Our research provides insights into the effects of long-term exposure to algal toxins on marine copepods and the potential impacts of climate warming.

Bioavailability profiling shows differences in OA, DTX1 and DTX2 toxins that justify their toxicity

The marine toxins of the Okadaic acid (OA) group are natural compounds produced by dinoflagellates that enters the food chain by accumulating in seafood. They are responsible for Diarrhetic Shellfish Poisoning (DSP) events in humans over the world and therefore are also jointly named as Diarrhetic Shellfish Toxins (DSTs). The main objective of this study was to evaluate symptoms, toxicity, absorption, distribution, and elimination of OA, Dinophysistoxin-1 (DTX1), and Dinophysistoxin-2 (DTX2) at the sublethal dose of 90 μg toxin/kg bw administered through voluntary feeding to mice. The toxin comparison highlighted that OA and DTX1 induced more severe and specific symptoms such as diarrhea. After oral ingestion toxins were distributed through the entire organism being detected in liver, kidney, stomach, small and large intestine. Predominant excretion of the toxins was observed in feces, with OA exhibiting fast elimination, while DTX2 was showing prolonged excretion. The passage and accumulation of toxins in gastrointestinal organs instigated macroscopic damage in the stomach, small and large intestine that could persist up to 120 h. These findings highlight the importance of pharmacokinetic of sublethal doses of DSTs administered by voluntary feeding in their toxicity and their implication for public health.

Prospects for the use of viral proteins for the construction of chimeric toxins.

One of the actively developing areas of drug development is the creation of chimeric toxins, recombinant bifunctional molecules designed to affect target cells selectively. The prevalent approach involves fusing bacterial and plant toxins with molecules that facilitate targeted delivery. However, the therapeutic use of such toxins often encounters challenges associated with negative side effects. Concurrently, viruses encode proteins possessing toxin-like properties, exerting multiple effects on the vital activity of cells. In contrast to bacterial and plant toxins, the impact of viral proteins is typically milder, presenting a significant advantage by potentially reducing the likelihood of side effects. This review delineates the characteristics of extensively studied viral proteins with toxic and immunomodulatory properties and explores the prospects of incorporating them into chimeric toxins.

History and Toxinology of Palytoxins.

Palytoxins are a group of highly potent and structurally complex marine toxins that rank among some of the most toxic substances known to science. Palytoxins are naturally synthesized by a variety of marine organisms, including Palythoa zoanthids, Ostreopsis dinoflagellates, and Trichodesmium cyanobacteria, and are widely distributed in tropical and temperate regions where they can bioaccumulate in marine life. The evolution of research on palytoxins has been an intricate exchange between interdisciplinary fields, drawing insights from chemistry, biology, medicine, and environmental science in efforts to better understand and mitigate the health risks associated with this family of toxins. In this review, we begin with a brief history covering the discovery of this group of toxins and the events that led to its isolation. We then focus on the chemical structure of these compounds and their proposed mechanism of action. Finally, we review in vitro, ex vivo, and in vivo studies related to their toxicity, with the aim to provide a broad overview of the current knowledge on palytoxin toxinology.

Enhanced Surveillance of &gt;1100 Pesticides and Natural Toxins in Food: Harnessing the Capabilities of LC-HRMS for Reliable Identification and Quantification

The consequences of climate change along with diverse food regulations and agricultural practices worldwide are complexifying the occurrence and management of chemical contaminants in food. In this context, we present an ultra-high-performance liquid chromatography high-resolution mass spectrometry (LC-HRMS) approach for the simultaneous identification and quantitation of over 1100 pesticide residues, mycotoxins, and plant toxins in cereals and fruits and vegetables. Analytical conditions were optimized to maximize the scope of the targeted molecules, the reliability of compound identification, and quantification performance within a single method. The method was further transferred and validated in another laboratory to assess its ruggedness. Validation according to the SANTE 11312/2021v2 guidelines showed that 92% and 98% of the molecules fulfill the quantification criteria at the lowest validated level in the cereals and fruits and vegetables groups, respectively. Analysis of fifteen certified reference materials led to a 96% satisfactory rate of z-scores confirming method’s competitiveness. Furthermore, the occurrence of these contaminants was studied in 205 cereals and grains samples collected worldwide. The low µg/kg quantification limits make this LC-HRMS method a valuable tool to ensure compliance toward regulations and to screen for non-regulated substances for which occurrence data are crucial for an appropriate risk evaluation.

Brevetoxin Aptamer Selection and Biolayer Interferometry Biosensor Application.

Brevetoxins (PbTxs) are very potent marine neurotoxins that can cause an illness clinically described as neurologic shellfish poisoning (NSP). These toxins are cyclic polyether in chemistry and have increased their geographical distribution in the past 2 decades. However, the ethical problems as well as technical difficulties associated with currently employed analysis methods for marine toxins have spurred the quest for suitable alternatives to be applied in a regulatory monitoring regime. In this work, we reported the first instance of concurrent aptamer selection of Brevetoxin-1 (PbTx-1) and Brevetoxin-2 (PbTx-2) and constructed a biolayer interferometry (BLI) biosensor utilizing PbTx-1 aptamer as a specific recognition element. Through an in vitro selection process, we have, for the first time, successfully selected DNA aptamers with high affinity and specificity to PbTx-1 and PbTx-2 from a vast pool of random sequences. Among the selected aptamers, aptamer A5 exhibited the strongest binding affinity to PbTx-1, with an equilibrium dissociation constant (KD) of 2.56 μM. Subsequently, we optimized aptamer A5 by truncation to obtain the core sequence (A5-S3). Further refinement was achieved through mutations based on the predictions of a QGRS mapper, resulting in aptamer A5-S3G, which showed a significant increase in the KD value by approximately 100-fold. Utilizing aptamer A5-S3G, we fabricated a label-free, real-time optical BLI aptasensor for the detection of PbTx-1. This aptasensor displayed a broad detection range from 100 nM to 4000 nM PbTx-1, with a linear range between 100 nM and 2000 nM, and a limit of detection (LOD) as low as 4.5 nM. Importantly, the aptasensor showed no cross-reactivity to PbTx-2 or other marine toxins, indicating a high level of specificity for PbTx-1. Moreover, the aptasensor exhibited excellent reproducibility and stability when applied for the detection of PbTx-1 in spiked shellfish samples. We strongly believe that this innovative aptasensor offers a promising alternative to traditional immunological methods for the specific and reliable detection of PbTx-1.

Exploring the anticancer potential of Cytotoxin 10 from Naja kaouthia venom: Mechanistic insights from breast and lung cancer cell lines

Breast and lung cancers are the leading causes of cancer-related deaths in the world. Although considerable progress has been made in the field of cancer therapy, quest to discover potent, safe and cost-effective alternatives especially from natural sources is being pursued. Snake venom, which is a treasure trove of various peptides and proteins including natural toxins that specifically target tissues and receptors in the envenomated victims. Many such proteins are being explored for their therapeutic potential against various diseases including cancers. Here, we report the mechanism of cytotoxic activity of crude venom and a purified protein, Cytotoxin from the monocled cobra (Naja kaouthia), an elapid snake with neurotoxic venom prominently found in the North-East India. The crude venom showed significant cytotoxicity against breast (MCF-7and MDA-MB-231) and lung (A549, NCI–H522) cancer cell lines. Bioassay-guided fractionation using RP-HPLC showed highest cytotoxic activity in peak P9. Liquid chromatography-tandem mass spectrometry (ESI-LC-MS/MS) analysis was employed and the fraction is identified as Cytotoxin 10 which showed comparable cytotoxicity against the experimental cell lines. Cytotoxin 10 also exhibited apoptosis in MCF-7 and A549 cell lines using AO/EtBr and flow cytometry analysis. Expressions of apoptosis related proteins e.g. Bax, Bcl-2, Caspase-7 and PARP were also studied following Cytotoxin 10 treatment in both cell lines. Molecular docking experiments performed to investigate the interactions between Cytotoxin 10 and the apoptotic proteins revealed favourable binding scores compared to their corresponding inhibitors. Interestingly, Cytotoxin 10 inhibited migration and adhesion in a time and dose-dependent manner in both MCF-7 and A549 cells. This is the first report elucidating the mechanism of cytotoxic activity of Cytotoxin 10 purified from Naja kaouthia venom of North-East India origin and could pave the way for development of potential therapeutic strategies against breast and lung cancer.

Integrated OPECT and Smartphone Colorimetry Dual‐Mode Detection of Okadaic Acid Based on Ce‐MOF Modified MXene@SnO2 Z‐Scheme Heterostructure

AbstractThe organic photoelectrochemical transistor (OPECT) biosensing relies solely on a singular signal readout inherently, which restrains the precision and dependability nestled within pertinent biological measurements. Herein, a high‐precision magnetic assisted OPECT and smartphone colorimetric (SCL) dual‐mode biosensing platform is first established for detecting harmful algal toxin okadaic acid (OA) by biocatalytic reaction. MXene@SnO2‐Ce‐MOF (MXSnO/Ce‐MOF) Z‐scheme heterojunctions with abundant oxygen vacancies are prepared as photoactive materials. Initially, in the presence of OA, the coupling of trigger DNA (tDNA) to magnetic beads (MBs) via anchor DNA (aDNA) is released through the interaction of the target analyte with the aptamer. Subsequently, the carried tDNA triggers HCR between the two hairpin sequences, producing long double helix chains to capture glucose oxidase (GOx). The obtained GOx supernatant catalyzes glucose to produce H2O2, which can oxidize Ce‐MOF, leading to the alteration of electrode color and a significant decrease in the overall photocurrent of MXSnO/Ce‐MOF. Crucially, the novel OPECT‐SCL biosensor exhibits excellent sensitivity and precision, boasting detection thresholds as low as 42.9 pM and 1.2 nM, respectively, and accomplishes the automated detection of OA within real samples. The proposed OPECT‐SCL dual‐signal measurement model constitutes a sensitive, portable, and precise platform for the quantification of marine toxins.

The impact of carvacrol on the larval gut bacterial structure and function of Lymantria dispar.

The gut bacteria of insects play an important role in regulating their metabolism, immune system and metabolizing pesticides. Our previous results indicate that carvacrol has certain gastric toxic activity on Lymantria dispar larvae and affects their detoxification metabolism at the mRNA level. However, the impact of carvacrol on the gut bacteria of L. dispar larvae has been unclear. In this study, the 16S rRNA sequencing technology was used to sequence and analyze the gut bacteria of the larvae which were exposed with sublethal concentration (0.297 mg/mL) and median lethal concentration (1.120 mg/mL), respectively. A total of 10 phyla, 16 classes, 47 orders, 72 families, 103 genera, and 135 species were obtained by using a 97% similarity cutoff level. The dominant bacterial phyla in the gut of the L. dispar larvae are Firmicutes and Proteobacteria. The treatment with carvacrol can significantly affect the structure of gut bacteria in the larvae of the L. dispar. At both doses, carvacrol can shift the dominant gut bacteria of the larvae from Proteobacteria to Firmicutes. At the genus level, two doses of carvacrol can significantly enhance the relative abundance of probiotic Lactobacillus in the gut of L. dispar larvae (p ≤ 0.01). Additionally, significant differences were observed among the five bacterial genera Burkholderia-Caballeronia-Paraburkholderia, Anoxybacillus, Pelomonas, Mesorhizobium (p ≤ 0.05). The analysis of α-diversity and β-diversity indicates that the treatment with carvacrol at two doses significantly affect the bacterial richness and diversity in the larvae. However, the results of functional classification prediction (PICRUSt) indicate that carvacrol significantly down-regulate 7 functions, including Energy metabolism, Cell growth and death, and up-regulate 2 functions, including Carbohydrate metabolism and Membrane transport. The network analysis indicates that the correlation between gut bacteria also has been changed. In addition, the insecticidal activity results of carvacrol against L. dispar larvae with gut bacteria elimination showed that gut bacteria can reduce the insecticidal activity of carvacrol against L. dispar larvae. This study provides a theoretical foundation for understanding the role of gut bacteria in detoxifying plant toxins and conferring pesticide resistance.

Investigating the protective properties of Panax ginseng and its constituents against biotoxins and metal toxicity: a mechanistic review.

Natural toxins are toxic substances produced by living microorganisms and cause harmful effects to other creatures, but not the organisms themselves. Based on the sources, they are classified into fungal, microbial, herbal, algae, and animal biotoxins. Metals, the oldest toxicants, are not created or destroyed by human industry as elements, just concentrated in the biosphere. An antidote can counteract the toxic effects of a drug or toxin or mitigate the adverse effects of a harmful substance. The potential antidote effects of Panax ginseng in organ toxicity have been proved by many scientific research projects. Herein, we are going to gather a comprehensive mechanistic review of the antidotal effects of ginseng and its main constituents against natural toxins and metal toxicity. In this regard, a literate search has been done in PubMed/Medline, Science Direct, and Scopus from 2000 until 2024. The gathered data showed the protective impacts of this golden plant and its secondary metabolites against aflatoxin, deoxynivalenol, three-nitro propionic acid, ochratoxin A, lipopolysaccharide, nicotine, aconite, domoic acid, α-synuclein, amyloid β, and glutamate as well as aluminum, cadmium, chrome, copper, iron, and lead. These antidotal effects occur by multi-functional mechanisms. It may be attributed to antioxidant, anti-inflammatory, and anti-apoptotic effects. Future research directions on the antidotal effects of ginseng against natural toxins and metal toxicity involve broadening the scope of studies to include a wider range of toxins and metals, exploring synergistic interactions with other natural compounds, and conducting more human clinical trials to validate the efficacy and safety of ginseng-based treatments.

Applications of Nuclear Magnetic Resonance Spectroscopy to Characterization of Marine Toxins

Applications of Nuclear Magnetic Resonance Spectroscopy to Characterization of Marine Toxins