Next Issue
Volume 2, September
Previous Issue
Volume 2, July
 
 

Toxins, Volume 2, Issue 8 (August 2010) – 16 articles , Pages 1928-2212

  • Issues are regarded as officially published after their release is announced to the table of contents alert mailing list.
  • You may sign up for e-mail alerts to receive table of contents of newly released issues.
  • PDF is the official format for papers published in both, html and pdf forms. To view the papers in pdf format, click on the "PDF Full-text" link, and use the free Adobe Reader to open them.
Order results
Result details
Section
Select all
Export citation of selected articles as:
179 KiB  
Article
Characterization of SNARE Cleavage Products Generated by Formulated Botulinum Neurotoxin Type-A Drug Products
by Terrence Hunt, David Rupp, Gary Shimizu, Karen Tam, Julia Weidler and Jack Xie
Toxins 2010, 2(8), 2198-2212; https://doi.org/10.3390/toxins2082198 - 19 Aug 2010
Cited by 11 | Viewed by 10471
Abstract
The study evaluated substrate cleavage product(s) generated by three botulinum neurotoxin serotype A (BoNT/A) medicinal drug products utilizing a novel and highly specific, light-chain activity, high-performance liquid chromatography (LCA-HPLC) method. Samples were reacted with a commercially available BoNT/A fluorescent substrate derived from the [...] Read more.
The study evaluated substrate cleavage product(s) generated by three botulinum neurotoxin serotype A (BoNT/A) medicinal drug products utilizing a novel and highly specific, light-chain activity, high-performance liquid chromatography (LCA-HPLC) method. Samples were reacted with a commercially available BoNT/A fluorescent substrate derived from the SNAP-25 sequence. Reaction products were separated by reversed-phase HPLC. The method detected an atypical cleavage pattern by one of the formulated drug products. IncobotulinumtoxinA produced two cleavage fragments rather than the single fragment typically generated by BoNT/A. Identification confirmed the secondary cleavage at a position corresponding to SNAP-25 Arg198–Ala199 (normal BoNT/A cleavage is Gln197–Arg198). Arg198–Ala199 is also the cleavage site for trypsin and serotype C toxin. Normal cleavage was observed for all other BoNT/A drug product samples, as well as 900-kD and 150-kD bulk toxin BoNT/A. The reason for this unexpected secondary cleavage pattern by one formulated BoNT/A drug product is unknown. Possible explanations include a contaminating protease and/or damage to the 150-kD type-A toxin causing nonspecific substrate recognition and subsequent cleavage uncharacteristic of type-A toxin. The BoNT/A drug products were also analyzed via the LCA-HPLC assay using a commercial BoNT/C fluorescent substrate derived from the syntaxin sequence. Cleavage of the serotype C substrate by incobotulinumtoxinA was also confirmed whilst neither of the other drug products cleaved the syntaxin substrate. Full article
(This article belongs to the Special Issue Toxins as Therapeutics)
Show Figures

Figure 1

577 KiB  
Review
Staphylococcal Enterotoxins
by Irina V. Pinchuk, Ellen J. Beswick and Victor E. Reyes
Toxins 2010, 2(8), 2177-2197; https://doi.org/10.3390/toxins2082177 - 18 Aug 2010
Cited by 384 | Viewed by 36233
Abstract
Staphylococcus aureus (S. aureus) is a Gram positive bacterium that is carried by about one third of the general population and is responsible for common and serious diseases. These diseases include food poisoning and toxic shock syndrome, which are caused by [...] Read more.
Staphylococcus aureus (S. aureus) is a Gram positive bacterium that is carried by about one third of the general population and is responsible for common and serious diseases. These diseases include food poisoning and toxic shock syndrome, which are caused by exotoxins produced by S. aureus. Of the more than 20 Staphylococcal enterotoxins, SEA and SEB are the best characterized and are also regarded as superantigens because of their ability to bind to class II MHC molecules on antigen presenting cells and stimulate large populations of T cells that share variable regions on the b chain of the T cell receptor. The result of this massive T cell activation is a cytokine bolus leading to an acute toxic shock. These proteins are highly resistant to denaturation, which allows them to remain intact in contaminated food and trigger disease outbreaks. A recognized problem is the emergence of multi-drug resistant strains of S. aureus and these are a concern in the clinical setting as they are a common cause of antibiotic-associated diarrhea in hospitalized patients. In this review, we provide an overview of the current understanding of these proteins. Full article
(This article belongs to the Special Issue Enterotoxins)
Show Figures

Figure 1

296 KiB  
Review
Different Types of Cell Death Induced by Enterotoxins
by Chiou-Feng Lin, Chia-Ling Chen, Wei-Ching Huang, Yi-Lin Cheng, Chia-Yuan Hsieh, Chi-Yun Wang and Ming-Yuan Hong
Toxins 2010, 2(8), 2158-2176; https://doi.org/10.3390/toxins2082158 - 11 Aug 2010
Cited by 26 | Viewed by 11783
Abstract
The infection of bacterial organisms generally causes cell death to facilitate microbial invasion and immune escape, both of which are involved in the pathogenesis of infectious diseases. In addition to the intercellular infectious processes, pathogen-produced/secreted enterotoxins (mostly exotoxins) are the major weapons that [...] Read more.
The infection of bacterial organisms generally causes cell death to facilitate microbial invasion and immune escape, both of which are involved in the pathogenesis of infectious diseases. In addition to the intercellular infectious processes, pathogen-produced/secreted enterotoxins (mostly exotoxins) are the major weapons that kill host cells and cause diseases by inducing different types of cell death, particularly apoptosis and necrosis. Blocking these enterotoxins with synthetic drugs and vaccines is important for treating patients with infectious diseases. Studies of enterotoxin-induced apoptotic and necrotic mechanisms have helped us to create efficient strategies to use against these well-characterized cytopathic toxins. In this article, we review the induction of the different types of cell death from various bacterial enterotoxins, such as staphylococcal enterotoxin B, staphylococcal alpha-toxin, Panton-Valentine leukocidin, alpha-hemolysin of Escherichia coli, Shiga toxins, cytotoxic necrotizing factor 1, heat-labile enterotoxins, and the cholera toxin, Vibrio cholerae. In addition, necrosis caused by pore-forming toxins, apoptotic signaling through cross-talk pathways involving mitochondrial damage, endoplasmic reticulum stress, and lysosomal injury is discussed. Full article
(This article belongs to the Special Issue Enterotoxins)
Show Figures

Graphical abstract

391 KiB  
Review
Toxin Mediated Diarrhea in the 21st Century: The Pathophysiology of Intestinal Ion Transport in the Course of ETEC, V. cholerae and Rotavirus Infection
by Sascha Kopic and John P. Geibel
Toxins 2010, 2(8), 2132-2157; https://doi.org/10.3390/toxins2082132 - 10 Aug 2010
Cited by 47 | Viewed by 13091
Abstract
An estimated 4 billion episodes of diarrhea occur each year. As a result, 2–3 million children and 0.5–1 million adults succumb to the consequences of this major healthcare concern. The majority of these deaths can be attributed to toxin mediated diarrhea by infectious [...] Read more.
An estimated 4 billion episodes of diarrhea occur each year. As a result, 2–3 million children and 0.5–1 million adults succumb to the consequences of this major healthcare concern. The majority of these deaths can be attributed to toxin mediated diarrhea by infectious agents, such as E. coli, V. cholerae or Rotavirus. Our understanding of the pathophysiological processes underlying these infectious diseases has notably improved over the last years. This review will focus on the cellular mechanism of action of the most common enterotoxins and the latest specific therapeutic approaches that have been developed to contain their lethal effects. Full article
(This article belongs to the Special Issue Enterotoxins)
Show Figures

Figure 1

214 KiB  
Review
Multiple Roles of Staphylococcus aureus Enterotoxins: Pathogenicity, Superantigenic Activity, and Correlation to Antibiotic Resistance
by Elena Ortega, Hikmate Abriouel, Rosario Lucas and Antonio Gálvez
Toxins 2010, 2(8), 2117-2131; https://doi.org/10.3390/toxins2082117 - 10 Aug 2010
Cited by 125 | Viewed by 13453
Abstract
Heat-stable enterotoxins are the most notable virulence factors associated with Staphylococcus aureus, a common pathogen associated with serious community and hospital acquired diseases. Staphylococcal enterotoxins (SEs) cause toxic shock-like syndromes and have been implicated in food poisoning. But SEs also act as [...] Read more.
Heat-stable enterotoxins are the most notable virulence factors associated with Staphylococcus aureus, a common pathogen associated with serious community and hospital acquired diseases. Staphylococcal enterotoxins (SEs) cause toxic shock-like syndromes and have been implicated in food poisoning. But SEs also act as superantigens that stimulate T-cell proliferation, and a high correlation between these activities has been detected. Most of the nosocomial S. aureus infections are caused by methicillin-resistant S. aureus (MRSA) strains, and those resistant to quinolones or multiresistant to other antibiotics are emerging, leaving a limited choice for their control. This review focuses on these diverse roles of SE, their possible correlations and the influence in disease progression and therapy. Full article
(This article belongs to the Special Issue Enterotoxins)
170 KiB  
Article
How Should Staphylococcal Food Poisoning Outbreaks Be Characterized?
by Jacques-Antoine Hennekinne, Annick Ostyn, Florence Guillier, Sabine Herbin, Anne-Laure Prufer and Sylviane Dragacci
Toxins 2010, 2(8), 2106-2116; https://doi.org/10.3390/toxins2082106 - 10 Aug 2010
Cited by 85 | Viewed by 12881
Abstract
Staphylococcal food poisoning is one of the most common food-borne diseases and results from the ingestion of staphylococcal enterotoxins (SEs) preformed in food by enterotoxigenic strains of Staphylococcus aureus. To date, more than 20 SEs have been described: SEA to SElV. All SEs [...] Read more.
Staphylococcal food poisoning is one of the most common food-borne diseases and results from the ingestion of staphylococcal enterotoxins (SEs) preformed in food by enterotoxigenic strains of Staphylococcus aureus. To date, more than 20 SEs have been described: SEA to SElV. All SEs have superantigenic activity whereas only a few have been proved to be emetic, representing a potential hazard for consumers. Characterization of staphylococcal food poisoning outbreaks (SFPOs) has considerably progressed compared to 80 years ago, when staphylococci were simply enumerated and only five enterotoxins were known for qualitative detection. Today, SFPOs can be characterized by a number of approaches, such as the identification of S. aureus biovars, PCR and RT-PCR methods to identify the se genes involved, immunodetection of specific SEs, and absolute quantification by mass spectrometry. An integrated gene-to-protein approach for characterizing staphylococcal food poisoning is advocated. Full article
(This article belongs to the Special Issue Enterotoxins)
Show Figures

Figure 1

189 KiB  
Article
Ochratoxin A Contamination of Food from Croatia
by Maja Peraica, Dubravka Flajs, Ana-Marija Domijan, Dario Ivić and Bogdan Cvjetković
Toxins 2010, 2(8), 2098-2105; https://doi.org/10.3390/toxins2082098 - 10 Aug 2010
Cited by 14 | Viewed by 9641
Abstract
Ochratoxin A (OTA) is a mycotoxin with nephrotoxic, genotoxic and carcinogenic properties produced by Penicillium and Aspergillus moulds under different climatic conditions. Humans and animals are exposed to this compound mainly via ingestion of contaminated food. In Croatia, research on mycotoxins focused on [...] Read more.
Ochratoxin A (OTA) is a mycotoxin with nephrotoxic, genotoxic and carcinogenic properties produced by Penicillium and Aspergillus moulds under different climatic conditions. Humans and animals are exposed to this compound mainly via ingestion of contaminated food. In Croatia, research on mycotoxins focused on OTA when the mycotoxin theory of endemic nephropathy (EN) was postulated. Ochratoxin A was more frequent and at higher concentration in foods from EN than those from the control regions. Subsequently, OTA concentrations were determined in some commodities intended for human consumption such as maize, wheat, beans and wine. Samples from all parts of Croatia were analyzed and OTA was found in all types of commodities. It was frequently found together with other mycotoxins (fumonisin B1, fumonisin B2 and zearalenone). In general, OTA concentration in foods from Croatia is low, but the frequency of positive samples shows considerable variations from year to year depending also on sampling location. Although low levels of OTA were found in a large proportion of analyzed food samples, its persistent co-occurrence with other significant mycotoxins should raise serious public health concerns as there interactions may be synergistic or additive in causing toxicity in humans and animals. There is need to establish control measures through which such contaminations in foods can be managed. Full article
(This article belongs to the Special Issue Ochratoxins)
534 KiB  
Article
Contrasting Nephropathic Responses to Oral Administration of Extract of Cultured Penicillium polonicum in Rat and Primate
by Peter G. Mantle, Katharine M. McHugh and John E. Fincham
Toxins 2010, 2(8), 2083-2097; https://doi.org/10.3390/toxins2082083 - 09 Aug 2010
Cited by 11 | Viewed by 12114
Abstract
Liquid- or solid substrate-cultured Penicillium polonicum administered in feed to rats over several days evokes a histopathological response in kidney involving apoptosis and abnormal mitosis in proximal tubules. The amphoteric toxin is yet only partly characterized, but can be isolated from cultured sporulating [...] Read more.
Liquid- or solid substrate-cultured Penicillium polonicum administered in feed to rats over several days evokes a histopathological response in kidney involving apoptosis and abnormal mitosis in proximal tubules. The amphoteric toxin is yet only partly characterized, but can be isolated from cultured sporulating biomass in a fraction that is soluble in water and ethanol, and exchangeable on either anion- or cation-exchange resins. After several weeks of treatment renal proximal tubule distortion became striking on account of karyocytomegaly, but even treatment for nearly two years remained asymptomatic. Extract from a batch of solid substrate fermentation of P. polonicum on shredded wheat was incorporated into feed for rats during four consecutive days, and also given as an aqueous solution by oral gavage to a vervet monkey daily for 10 days. Treatment was asymptomatic for both types of animal. Rat response was evident as the typical renal apoptosis and karyomegaly. In contrast there was no such response in the primate; and neither creatinine clearance nor any haematological characteristic or serum component concentration deviated from a control or from historical data for this primate. The contrast is discussed concerning other negative findings for P. polonicum in pigs and hamsters. Renal karyomegaly, as a common rat response to persistent exposure to ochratoxin A, is not known in humans suspected as being exposed to more than the usual trace amounts of dietary ochratoxin A. Therefore the present findings question assumptions that human response to ochratoxin A conforms to that in the rat. Full article
(This article belongs to the Special Issue Renal Toxicity)
Show Figures

Graphical abstract

173 KiB  
Review
Assessment of the Role of Renal Organic Anion Transporters in Drug-Induced Nephrotoxicity
by Yohannes Hagos and Natascha A. Wolff
Toxins 2010, 2(8), 2055-2082; https://doi.org/10.3390/toxins2082055 - 09 Aug 2010
Cited by 74 | Viewed by 14450
Abstract
In the present review we have attempted to assess the involvement of the organic anion transporters OAT1, OAT2, OAT3, and OAT4, belonging to the SLC22 family of polyspecific carriers, in drug-induced renal damage in humans. We have focused on drugs with widely recognized [...] Read more.
In the present review we have attempted to assess the involvement of the organic anion transporters OAT1, OAT2, OAT3, and OAT4, belonging to the SLC22 family of polyspecific carriers, in drug-induced renal damage in humans. We have focused on drugs with widely recognized nephrotoxic potential, which have previously been reported to interact with OAT family members, and whose underlying pathogenic mechanism suggests the participation of tubular transport. Thus, only compounds generally believed to cause kidney injury either by means of direct tubular toxicity or crystal nephropathy have been considered. For each drug, or class of agents, the evidence for actual transport mediated by individual OATs under in vivo conditions is discussed. We have then examined their role in the context of other carriers present in the renal proximal tubule sharing certain substrates with OATs, as these are critical determinants of the overall contribution of OAT-dependent transport to intracellular accumulation and transepithelial drug secretion, and thus the impact it may have in drug-induced nephrotoxicity. Full article
(This article belongs to the Special Issue Renal Toxicity)
Show Figures

Figure 1

427 KiB  
Review
Bacterial Heat-Stable Enterotoxins: Translation of Pathogenic Peptides into Novel Targeted Diagnostics and Therapeutics
by Jieru E. Lin, Michael Valentino, Glen Marszalowicz, Michael S. Magee, Peng Li, Adam E. Snook, Brian A. Stoecker, Chang Chang and Scott A. Waldman
Toxins 2010, 2(8), 2028-2054; https://doi.org/10.3390/toxins2082028 - 05 Aug 2010
Cited by 31 | Viewed by 14475
Abstract
Heat-stable toxins (STs) produced by enterotoxigenic bacteria cause endemic and traveler’s diarrhea by binding to and activating the intestinal receptor guanylyl cyclase C (GC-C). Advances in understanding the biology of GC-C have extended ST from a diarrheagenic peptide to a novel therapeutic agent. [...] Read more.
Heat-stable toxins (STs) produced by enterotoxigenic bacteria cause endemic and traveler’s diarrhea by binding to and activating the intestinal receptor guanylyl cyclase C (GC-C). Advances in understanding the biology of GC-C have extended ST from a diarrheagenic peptide to a novel therapeutic agent. Here, we summarize the physiological and pathophysiological role of GC-C in fluid-electrolyte regulation and intestinal crypt-villus homeostasis, as well as describe translational opportunities offered by STs, reflecting the unique characteristics of GC-C, in treating irritable bowel syndrome and chronic constipation, and in preventing and treating colorectal cancer. Full article
(This article belongs to the Special Issue Enterotoxins)
Show Figures

Figure 1

609 KiB  
Article
Unexpected Modulation of Recall B and T Cell Responses after Immunization with Rotavirus-like Particles in the Presence of LT-R192G
by Fatou Thiam, Cyrille Di Martino, Fabienne Bon, Annie Charpilienne, Claire Cachia, Didier Poncet, John D. Clements, Christelle Basset and Evelyne Kohli
Toxins 2010, 2(8), 2007-2027; https://doi.org/10.3390/toxins2082007 - 05 Aug 2010
Cited by 4 | Viewed by 8950
Abstract
LT-R192G, a mutant of the thermolabile enterotoxin of E. coli, is a potent adjuvant of immunization. Immune responses are generally analyzed at the end of protocols including at least 2 administrations, but rarely after a prime. To investigate this point, we compared [...] Read more.
LT-R192G, a mutant of the thermolabile enterotoxin of E. coli, is a potent adjuvant of immunization. Immune responses are generally analyzed at the end of protocols including at least 2 administrations, but rarely after a prime. To investigate this point, we compared B and T cell responses in mice after one and two intrarectal immunizations with 2/6 rotavirus-like particles (2/6-VLP) and LT-R192G. After a boost, we found, an unexpected lower B cell expansion measured by flow cytometry, despite a secondary antibody response. We then analyzed CD4+CD25+Foxp3+ regulatory T cells (Tregs) and CD4+CD25+Foxp3 helper T cells after in vitro (re)stimulation of mesenteric lymph node cells with the antigen (2/6-VLP), the adjuvant (LT-R192G) or both. 2/6-VLP did not activate CD4+CD25+Foxp3 nor Foxp3+ T cells from non-immunized and 2/6-VLP immunized mice, whereas they did activate both subsets from mice immunized with 2/6-VLP in the presence of adjuvant. LT-R192G dramatically decreased CD4+CD25+Foxp3+ T cells from non-immunized and 2/6-VLP immunized mice but not from mice immunized with 2/6-VLP and adjuvant. Moreover, in this case, LT-R192G increased Foxp3 expression on CD4+CD25+Foxp3+ cells, suggesting specific Treg activation during the recall. Finally, when both 2/6-VLP and LT-R192G were used for restimulation, LT-R192G clearly suppressed both 2/6-VLP-specific CD4+CD25+Foxp3 and Foxp3+ T cells. All together, these results suggest that LT-R192G exerts different effects on CD4+CD25+Foxp3+ T cells, depending on a first or a second contact. The unexpected immunomodulation observed during the recall should be considered in designing vaccination protocols. Full article
(This article belongs to the Special Issue Enterotoxins)
Show Figures

Figure 1

760 KiB  
Article
Distribution of Gb3 Immunoreactivity in the Mouse Central Nervous System
by Fumiko Obata and Tom Obrig
Toxins 2010, 2(8), 1997-2006; https://doi.org/10.3390/toxins2081997 - 04 Aug 2010
Cited by 8 | Viewed by 8478
Abstract
We have shown previously that neurons in the mouse spinal cord express Gb3. We show in this article that distribution of anti-Gb3-Ab reactivity occurs in many different types of neurons of different areas of the central nervous system (CNS). [...] Read more.
We have shown previously that neurons in the mouse spinal cord express Gb3. We show in this article that distribution of anti-Gb3-Ab reactivity occurs in many different types of neurons of different areas of the central nervous system (CNS). The immunoreactive neurons are in olfactory bulbs, cerebral cortex, hippocampus, striatum, amygdala, thalamus, hypothalamus, cerebellum, and medulla oblongata. In several different circumventricular organs where vessels do not have the blood-brain-barrier (BBB) structure, anti-Gb3-Ab is not positive for vessel structures, while neurons at these regions are positive. Also, within the ventricular area, ependymal cells in the third ventricle express Gb3, as revealed by anti-Gb3-Ab staining and intensity analysis. Full article
(This article belongs to the Special Issue Novel Properties of Well-Characterized Toxins)
Show Figures

Figure 1

199 KiB  
Article
Natural Occurrence of Ochratoxin A in Musts, Wines and Grape Vine Fruits from Grapes Harvested in Argentina
by María Lorena Ponsone, María Laura Chiotta, Mariana Combina, Adriana Torres, Patricia Knass, Ana Dalcero and Sofía Chulze
Toxins 2010, 2(8), 1984-1996; https://doi.org/10.3390/toxins2081984 - 03 Aug 2010
Cited by 22 | Viewed by 9306
Abstract
In this study, ochratoxin A (OTA) occurrence in Argentinean musts, wines and dried vine fruits was evaluated, alongside with the performance of OchraStarTM columns for OTA extraction. In all the three matrices analyzed, the OchraStarTM columns showed good performance. The analysis [...] Read more.
In this study, ochratoxin A (OTA) occurrence in Argentinean musts, wines and dried vine fruits was evaluated, alongside with the performance of OchraStarTM columns for OTA extraction. In all the three matrices analyzed, the OchraStarTM columns showed good performance. The analysis of natural occurrence of OTA in the red must and the red wine samples showed low incidence with low levels of mean OTA contamination (0.12 ng/mL and 0.37 ng/mL, respectively), while 60% of the dried vine fruit samples were contaminated with OTA, in levels ranging from 0.26 to 20.28 ng/g. Full article
(This article belongs to the Special Issue Ochratoxins)
Show Figures

Figure 1

356 KiB  
Review
Therapeutic Down-Modulators of Staphylococcal Superantigen-Induced Inflammation and Toxic Shock
by Teresa Krakauer
Toxins 2010, 2(8), 1963-1983; https://doi.org/10.3390/toxins2081963 - 29 Jul 2010
Cited by 19 | Viewed by 13816
Abstract
Staphylococcal enterotoxin B (SEB) and related superantigenic toxins are potent stimulators of the immune system and cause a variety of diseases in humans, ranging from food poisoning to toxic shock. These toxins bind directly to major histocompatibility complex (MHC) class II molecules on [...] Read more.
Staphylococcal enterotoxin B (SEB) and related superantigenic toxins are potent stimulators of the immune system and cause a variety of diseases in humans, ranging from food poisoning to toxic shock. These toxins bind directly to major histocompatibility complex (MHC) class II molecules on antigen-presenting cells and specific Vb regions of T-cell receptors (TCR), resulting in hyperactivation of both monocytes/macrophages and T lymphocytes. Activated host cells produce massive amounts of proinflammatory cytokines and chemokines, activating inflammation and coagulation, causing clinical symptoms that include fever, hypotension, and shock. This review summarizes the in vitro and in vivo effects of staphylococcal superantigens, the role of pivotal mediators induced by these toxins in the pathogenic mechanisms of tissue injury, and the therapeutic agents to mitigate the toxic effects of superantigens. Full article
(This article belongs to the Special Issue Enterotoxins)
Show Figures

Figure 1

229 KiB  
Review
Natural Toxins for Use in Pest Management
by Stephen O. Duke, Charles L. Cantrell, Kumudini M. Meepagala, David E. Wedge, Nurhayat Tabanca and Kevin K. Schrader
Toxins 2010, 2(8), 1943-1962; https://doi.org/10.3390/toxins2081943 - 29 Jul 2010
Cited by 144 | Viewed by 17749
Abstract
Natural toxins are a source of new chemical classes of pesticides, as well as environmentally and toxicologically safer molecules than many of the currently used pesticides. Furthermore, they often have molecular target sites that are not exploited by currently marketed pesticides. There are [...] Read more.
Natural toxins are a source of new chemical classes of pesticides, as well as environmentally and toxicologically safer molecules than many of the currently used pesticides. Furthermore, they often have molecular target sites that are not exploited by currently marketed pesticides. There are highly successful products based on natural compounds in the major pesticide classes. These include the herbicide glufosinate (synthetic phosphinothricin), the spinosad insecticides, and the strobilurin fungicides. These and other examples of currently marketed natural product-based pesticides, as well as natural toxins that show promise as pesticides from our own research are discussed. Full article
(This article belongs to the Special Issue The Toxicity of Natural Products)
Show Figures

Figure 1

288 KiB  
Article
Ochratoxin A in Roasted Coffee from French Supermarkets and Transfer in Coffee Beverages: Comparison of Analysis Methods
by Mariana Tozlovanu and Annie Pfohl-Leszkowicz
Toxins 2010, 2(8), 1928-1942; https://doi.org/10.3390/toxins2081928 - 28 Jul 2010
Cited by 59 | Viewed by 9472
Abstract
The OTA content of 30 roasted coffees purchased in French supermarkets was evaluated by two validated different methods: one using immunoaffinity column (IAC) clean-up after alkaline extraction; the second using toluene extraction under acidic conditions. OTA recoveries (0.5 to 5 µg/kg) ranged from [...] Read more.
The OTA content of 30 roasted coffees purchased in French supermarkets was evaluated by two validated different methods: one using immunoaffinity column (IAC) clean-up after alkaline extraction; the second using toluene extraction under acidic conditions. OTA recoveries (0.5 to 5 µg/kg) ranged from 16–49% with the alkaline extraction method and 55–60% with the acidic method. OTA recoveries from prepared beverages were similar with all methods (75–80%). All samples containing OTA ranged from trace (<LOQ) to 11.9 µg/kg. About 20 to 140% of OTA passed through the beverages. Recoveries of over 100% of OTA in beverages were due to three types of interferences: (i) formation of open-ring OTA (OP-OA) during alkaline extraction, (ii) isomerization of OTA during roasting, and (iii) presence of the nonchlorinated analogue OTB. The first two types of interference generate OTA derivatives that are not recognized by OTA antibodies, while OTB cross-reacts with OTA-antibodies. These analytical problems will seriously impact the amount of OTA detected, especially at the levels close to the limits from the EU legislation. Underestimation of OTA could be highly dangerous for health. Full article
Show Figures

Figure 1

Previous Issue
Next Issue
Back to TopTop