Next Issue
Previous Issue

E-Mail Alert

Add your e-mail address to receive forthcoming issues of this journal:

Journal Browser

Journal Browser

Table of Contents

Toxins, Volume 7, Issue 12 (December 2015)

  • 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 Readerexternal link to open them.
View options order results:
result details:
Displaying articles 1-45
Export citation of selected articles as:
Open AccessArticle
Bovine Lactoferrin-Induced CCL1 Expression Involves Distinct Receptors in Monocyte-Derived Dendritic Cells and Their Monocyte Precursors
Toxins 2015, 7(12), 5472-5483; https://doi.org/10.3390/toxins7124897
Received: 18 November 2015 / Revised: 2 December 2015 / Accepted: 9 December 2015 / Published: 17 December 2015
Cited by 2 | Viewed by 2027 | PDF Full-text (1332 KB) | HTML Full-text | XML Full-text
Abstract
Lactoferrin (LF) exhibits a wide range of immunomodulatory activities including modulation of cytokine and chemokine secretion. In this study, we demonstrate that bovine LF (bLF) up-modulates, in a concentration- and time-dependent manner, CCL1 secretion in monocytes (Mo) at the early stage of differentiation [...] Read more.
Lactoferrin (LF) exhibits a wide range of immunomodulatory activities including modulation of cytokine and chemokine secretion. In this study, we demonstrate that bovine LF (bLF) up-modulates, in a concentration- and time-dependent manner, CCL1 secretion in monocytes (Mo) at the early stage of differentiation toward dendritic cells (DCs), and in fully differentiated immature Mo-derived DCs (MoDCs). In both cell types, up-modulation of CCL1 secretion is an early event following bLF-mediated enhanced accumulation of CCL1 transcripts. Notably, bLF-mediated up-regulation of CCL1 involves the engagement of distinct surface receptors in MoDCs and their Mo precursors. We show that bLF-mediated engagement of CD36 contributes to CCL1 induction in differentiating Mo. Conversely, toll-like receptor (TLR)2 blocking markedly reduces bLF-induced CCL1 production in MoDCs. These findings add further evidence for cell-specific differential responses elicited by bLF through the engagement of distinct TLRs and surface receptors. Furthermore, the different responses observed at early and late stages of Mo differentiation towards DCs may be relevant in mediating bLF effects in specific body districts, where these cell types may be differently represented in physiopathological conditions. Full article
(This article belongs to the Special Issue G-Protein Coupled Receptors as mediators of Toxin effects)
Figures

Figure 1

Open AccessArticle
Does Reduction of Number of Intradetrusor Injection Sites of aboBoNTA (Dysport®) Impact Efficacy and Safety in a Rat Model of Neurogenic Detrusor Overactivity?
Toxins 2015, 7(12), 5462-5471; https://doi.org/10.3390/toxins7124896
Received: 9 October 2015 / Revised: 3 December 2015 / Accepted: 10 December 2015 / Published: 17 December 2015
Viewed by 2862 | PDF Full-text (1146 KB) | HTML Full-text | XML Full-text
Abstract
Intradetrusor injections of Botulinum toxin A—currently onabotulinumtoxinA—is registered as a second-line treatment to treat neurogenic detrusor overactivity (NDO). The common clinical practice is 30 × 1 mL injections in the detrusor; however, protocols remain variable and standardization is warranted. The effect of [...] Read more.
Intradetrusor injections of Botulinum toxin A—currently onabotulinumtoxinA—is registered as a second-line treatment to treat neurogenic detrusor overactivity (NDO). The common clinical practice is 30 × 1 mL injections in the detrusor; however, protocols remain variable and standardization is warranted. The effect of reducing the number of injection sites of Dysport® abobotulinumtoxinA (aboBoNTA) was assessed in the spinal cord-injured rat (SCI). Nineteen days post-spinalization, female rats received intradetrusor injections of saline or aboBoNTA 22.5 U distributed among four or eight sites. Two days after injection, continuous cystometry was performed in conscious rats. Efficacy of aboBoNTA 22.5 U was assessed versus aggregated saline groups on clinically-relevant parameters: maximal pressure, bladder capacity, compliance, voiding efficiency, as well as amplitude, frequency, and volume threshold for nonvoiding contractions (NVC). AboBoNTA 22.5 U significantly decreased maximal pressure, without affecting voiding efficiency. Injected in four sites, aboBoNTA significantly increased bladder capacity and compliance while only the latter when in eight sites. AboBoNTA significantly reduced NVC frequency and amplitude. This preclinical investigation showed similar inhibiting effects of aboBoNTA despite the number of sites reduction. Further studies are warranted to optimize dosing schemes to improve the risk-benefit ratio of BoNTA-based treatment modalities for NDO and further idiopathic overactive bladder. Full article
(This article belongs to the Special Issue Botulinum Toxin A on Lower Urinary Tract Dysfunction)
Figures

Figure 1

Open AccessEditorial
Toxins: State of Journal Report, 2016
Toxins 2015, 7(12), 5459-5461; https://doi.org/10.3390/toxins7124895
Received: 9 December 2015 / Accepted: 9 December 2015 / Published: 15 December 2015
Viewed by 1348 | PDF Full-text (1241 KB) | HTML Full-text | XML Full-text
Abstract
In the “Message from the Editor-in-Chief” posted on the Toxins website (see www.mdpi.com/journal/toxins/toxins-flyer.pdf), we wrote: “The editorial board and staff of Toxins are dedicated to providing a timely, peer-reviewed outlet for exciting, innovative primary research articles and concise, informative reviews from investigators in [...] Read more.
In the “Message from the Editor-in-Chief” posted on the Toxins website (see www.mdpi.com/journal/toxins/toxins-flyer.pdf), we wrote: “The editorial board and staff of Toxins are dedicated to providing a timely, peer-reviewed outlet for exciting, innovative primary research articles and concise, informative reviews from investigators in the myriad of disciplines contributing to our knowledge on toxins. [...] Full article
Figures

Figure 1

Open AccessArticle
Different Effects of Bacillus thuringiensis Toxin Cry1Ab on Midgut Cell Transmembrane Potential of Mythimna separata and Agrotis ipsilon Larvae
Toxins 2015, 7(12), 5448-5458; https://doi.org/10.3390/toxins7124894
Received: 3 November 2015 / Revised: 23 November 2015 / Accepted: 9 December 2015 / Published: 15 December 2015
Cited by 5 | Viewed by 1530 | PDF Full-text (1003 KB) | HTML Full-text | XML Full-text
Abstract
Bacillus thuringiensis (Bt) Cry toxins from the Cry1A family demonstrate significantly different toxicities against members of the family Noctuidae for unknown reasons. In this study, membrane potential was measured and analyzed in freshly isolated midgut samples from Mythimna separata and Agrotis [...] Read more.
Bacillus thuringiensis (Bt) Cry toxins from the Cry1A family demonstrate significantly different toxicities against members of the family Noctuidae for unknown reasons. In this study, membrane potential was measured and analyzed in freshly isolated midgut samples from Mythimna separata and Agrotis ipsilon larvae under oral administration and in vitro incubation with Bt toxin Cry1Ab to elucidate the mechanism of action for further control of these pests. Bioassay results showed that the larvae of M. separata achieved a LD50 of 258.84 ng/larva at 24 h after ingestion; M. separata larvae were at least eightfold more sensitive than A. ipsilon larvae to Cry1Ab. Force-feeding showed that the observed midgut apical-membrane potential (Vam) of M. separata larvae was significantly depolarized from −82.9 ± 6.6 mV to −19.9 ± 7.2 mV at 8 h after ingestion of 1 μg activated Cry1Ab, whereas no obvious changes were detected in A. ipsilon larvae with dosage of 5 μg Cry1Ab. The activated Cry1Ab caused a distinct concentration-dependent depolarization of the apical membrane; Vam was reduced by 50% after 14.7 ± 0.2, 9.8 ± 0.4, and 7.6 ± 0.6 min of treatment with 1, 5, and 10 μg/mL Cry1Ab, respectively. Cry1Ab showed a minimal effect on A. ipsilon larvae even at 20 μg/mL, and Vam decreased by 26.3% ± 2.3% after 15 min. The concentrations of Cry1Ab displayed no significant effect on the basolateral side of the epithelium. The Vam of A. ipsilon (−33.19 ± 6.29 mV, n = 51) was only half that of M. separata (−80.94 ± 6.95 mV, n = 75). The different degrees of sensitivity to Cry1Ab were speculatively associated with various habits, as well as the diverse physiological or biochemical characteristics of the midgut cell membranes. Full article
Figures

Figure 1

Open AccessArticle
Molecular Mechanisms of Lipoic Acid Protection against Aflatoxin B1-Induced Liver Oxidative Damage and Inflammatory Responses in Broilers
Toxins 2015, 7(12), 5435-5447; https://doi.org/10.3390/toxins7124879
Received: 24 August 2015 / Revised: 19 November 2015 / Accepted: 23 November 2015 / Published: 14 December 2015
Cited by 21 | Viewed by 2102 | PDF Full-text (1642 KB) | HTML Full-text | XML Full-text
Abstract
Alpha-lipoic acid (α-LA) was evaluated in this study for its molecular mechanisms against liver oxidative damage and inflammatory responses induced by aflatoxin B1 (AFB1). Birds were randomly allocated into four groups with different diets for three weeks: a basal diet, [...] Read more.
Alpha-lipoic acid (α-LA) was evaluated in this study for its molecular mechanisms against liver oxidative damage and inflammatory responses induced by aflatoxin B1 (AFB1). Birds were randomly allocated into four groups with different diets for three weeks: a basal diet, a 300 mg/kg α-LA supplementation in a basal diet, a diet containing 74 μg/kg AFB1, and 300 mg/kg α-LA supplementation in a diet containing 74 μg/kg AFB1. In the AFB1 group, the expression of GSH-PX mRNA was down-regulated (p < 0.05), and the levels of lipid peroxide and nitric oxide were increased (p < 0.05) in the chicken livers compared to those of the control group. Additionally, the mRNA level of the pro-inflammatory factor interleukin-6 was up-regulated significantly (p < 0.05), the protein expressions of both the nuclear factor kappa B (NF-κB) p65 and the inducible nitric oxide synthase were enhanced significantly (p < 0.05) in the AFB1 group. All of these negative effects were inhibited by α-LA. These results indicate that α-LA may be effective in preventing hepatic oxidative stress, down-regulating the expression of hepatic pro-inflammatory cytokines, as well as inhibiting NF-κB expression. Full article
(This article belongs to the Section Mycotoxins)
Figures

Figure 1

Open AccessReview
Does Bacillus anthracis Lethal Toxin Directly Depress Myocardial Function? A Review of Clinical Cases and Preclinical Studies
Toxins 2015, 7(12), 5417-5434; https://doi.org/10.3390/toxins7124891
Received: 4 November 2015 / Revised: 24 November 2015 / Accepted: 7 December 2015 / Published: 12 December 2015
Cited by 6 | Viewed by 1973 | PDF Full-text (1540 KB) | HTML Full-text | XML Full-text
Abstract
The US outbreak of B.anthracis infection in 2001 and subsequent cases in the US and Europe demonstrate that anthrax is a continuing risk for the developed world. While several bacterial components contribute to the pathogenesis of B. anthracis, production of lethal toxin [...] Read more.
The US outbreak of B.anthracis infection in 2001 and subsequent cases in the US and Europe demonstrate that anthrax is a continuing risk for the developed world. While several bacterial components contribute to the pathogenesis of B. anthracis, production of lethal toxin (LT) is strongly associated with the development of hypotension and lethality. However, the mechanisms underlying the cardiovascular instability LT produces are unclear. Some evidence suggests that LT causes shock by impairing the peripheral vasculature, effects consistent with the substantial extravasation of fluid in patients dying with B. anthracis. Other data suggests that LT directly depresses myocardial function. However a clinical correlate for this latter possibility is less evident since functional studies and post-mortem examination in patients demonstrate absent or minimal cardiac changes. The purposes of this review were to first present clinical studies of cardiac functional and histologic pathology with B. anthracis infection and to then examine in vivo, in vitro, and ex vivo preclinical studies of LT’s myocardial effects. Together, these data suggest that it is unclear whether that LT directly depresses cardiac function. This question is important for the clinical management and development of new therapies for anthrax and efforts should continue to be made to answer it. Full article
(This article belongs to the collection Anthrax Toxins)
Figures

Figure 1

Open AccessFeature PaperReview
Toxicosis by Plant Alkaloids in Humans and Animals in Colombia
Toxins 2015, 7(12), 5408-5416; https://doi.org/10.3390/toxins7124892
Received: 3 November 2015 / Revised: 19 November 2015 / Accepted: 4 December 2015 / Published: 11 December 2015
Cited by 9 | Viewed by 2094 | PDF Full-text (188 KB) | HTML Full-text | XML Full-text
Abstract
Due to its tropical location, chains of mountains, inter-Andean valleys, Amazon basin area, eastern plains and shores on both the Atlantic and Pacific Oceans, Colombia has many ecosystems and the second largest plant biodiversity in the world. Many plant species, both native and [...] Read more.
Due to its tropical location, chains of mountains, inter-Andean valleys, Amazon basin area, eastern plains and shores on both the Atlantic and Pacific Oceans, Colombia has many ecosystems and the second largest plant biodiversity in the world. Many plant species, both native and naturalized, are currently recognized as toxic for both animals and humans, and some of them are known to cause their toxic effects due to their alkaloid content. Among these, there are plants containing the hepatotoxic pyrrolizidine alkaloids, neurotoxins such as the indolizidine alkaloid swainsonine and the piperidine alkaloids coniine and γ-coniceine and tropane alkaloids. Unfortunately, the research in toxic plants in Colombia is not nearly proportional to its plant biodiversity and the scientific information available is only very scarce. The present review aims at summarizing the scarce information about plant alkaloid toxicosis in animals and humans in Colombia. Full article
(This article belongs to the collection Toxicity of Natural Alkaloids)
Open AccessReview
Conotoxins That Could Provide Analgesia through Voltage Gated Sodium Channel Inhibition
Toxins 2015, 7(12), 5386-5407; https://doi.org/10.3390/toxins7124890
Received: 14 August 2015 / Revised: 23 October 2015 / Accepted: 19 November 2015 / Published: 10 December 2015
Cited by 8 | Viewed by 2134 | PDF Full-text (539 KB) | HTML Full-text | XML Full-text
Abstract
Chronic pain creates a large socio-economic burden around the world. It is physically and mentally debilitating, and many suffers are unresponsive to current therapeutics. Many drugs that provide pain relief have adverse side effects and addiction liabilities. Therefore, a great need has risen [...] Read more.
Chronic pain creates a large socio-economic burden around the world. It is physically and mentally debilitating, and many suffers are unresponsive to current therapeutics. Many drugs that provide pain relief have adverse side effects and addiction liabilities. Therefore, a great need has risen for alternative treatment strategies. One rich source of potential analgesic compounds that has immerged over the past few decades are conotoxins. These toxins are extremely diverse and display selective activity at ion channels. Voltage gated sodium (NaV) channels are one such group of ion channels that play a significant role in multiple pain pathways. This review will explore the literature around conotoxins that bind NaV channels and determine their analgesic potential. Full article
(This article belongs to the Special Issue Conotoxins: Novel Pharmacologies for Nervous System Disorders)
Figures

Figure 1

Open AccessArticle
Highly Sensitive Colorimetric Detection of Ochratoxin A by a Label-Free Aptamer and Gold Nanoparticles
Toxins 2015, 7(12), 5377-5385; https://doi.org/10.3390/toxins7124883
Received: 16 October 2015 / Revised: 30 November 2015 / Accepted: 1 December 2015 / Published: 10 December 2015
Cited by 17 | Viewed by 2601 | PDF Full-text (3621 KB) | HTML Full-text | XML Full-text
Abstract
A label-free aptamer-based assay for the highly sensitive and specific detection of Ochratoxin A (OTA) was developed using a cationic polymer and gold nanoparticles (AuNPs). The OTA aptamer was used as a recognition element for the colorimetric detection of OTA based on the [...] Read more.
A label-free aptamer-based assay for the highly sensitive and specific detection of Ochratoxin A (OTA) was developed using a cationic polymer and gold nanoparticles (AuNPs). The OTA aptamer was used as a recognition element for the colorimetric detection of OTA based on the aggregation of AuNPs by the cationic polymer. By spectroscopic quantitative analysis, the colorimetric assay could detect OTA down to 0.009 ng/mL with high selectivity in the presence of other interfering toxins. This study offers a new alternative in visual detection methods that is rapid and sensitive for OTA detection. Full article
(This article belongs to the collection Biorecognition Assays for Mycotoxins)
Figures

Figure 1

Open AccessArticle
Prophage-Encoded Staphylococcal Enterotoxin A: Regulation of Production in Staphylococcus aureus Strains Representing Different Sea Regions
Toxins 2015, 7(12), 5359-5376; https://doi.org/10.3390/toxins7124889
Received: 11 October 2015 / Revised: 26 November 2015 / Accepted: 30 November 2015 / Published: 9 December 2015
Cited by 7 | Viewed by 2397 | PDF Full-text (3202 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
The present study investigates the nature of the link between the staphylococcal enterotoxin A (SEA) gene and the lifecycle of Siphoviridae bacteriophages, including the origin of strain variation regarding SEA production after prophage induction. Five strains representing three different genetic lines of the [...] Read more.
The present study investigates the nature of the link between the staphylococcal enterotoxin A (SEA) gene and the lifecycle of Siphoviridae bacteriophages, including the origin of strain variation regarding SEA production after prophage induction. Five strains representing three different genetic lines of the sea region were studied under optimal and prophage-induced growth conditions and the Siphoviridae lifecycle was followed through the phage replicative form copies and transcripts of the lysogenic repressor, cro. The role of SOS response on prophage induction was addressed through recA transcription in a recA-disruption mutant. Prophage induction was found to increase the abundance of the phage replicative form, the sea gene copies and transcripts and enhance SEA production. Sequence analysis of the sea regions revealed that observed strain variances were related to strain capacity for prophage induction, rather than sequence differences in the sea region. The impact of SOS response activation on the phage lifecycle was demonstrated by the absence of phage replicative form copies in the recA-disruption mutant after prophage induction. From this study it emerges that all aspects of SEA-producing strain, the Siphoviridae phage and the food environment must be considered when evaluating SEA-related hazards. Full article
(This article belongs to the collection Staphylococcus aureus Toxins)
Figures

Figure 1

Open AccessArticle
Toxicological Evaluation of a Potential Immunosensitizer for Use as a Mucosal Adjuvant—Bacillus thuringiensis Cry1Ac Spore-Crystals: A Possible Inverse Agonist that Deserves Further Investigation
Toxins 2015, 7(12), 5348-5358; https://doi.org/10.3390/toxins7124881
Received: 14 August 2015 / Revised: 15 September 2015 / Accepted: 9 October 2015 / Published: 9 December 2015
Cited by 1 | Viewed by 1704 | PDF Full-text (220 KB) | HTML Full-text | XML Full-text
Abstract
In addition to their applicability as biopesticides, Bacillus thuringiensis (Bt) Cry1Ac spore-crystals are being researched in the immunology field for their potential as adjuvants in mucosal and parenteral immunizations. We aimed to investigate the hematotoxicity and genotoxicity of Bt spore-crystals genetically modified to [...] Read more.
In addition to their applicability as biopesticides, Bacillus thuringiensis (Bt) Cry1Ac spore-crystals are being researched in the immunology field for their potential as adjuvants in mucosal and parenteral immunizations. We aimed to investigate the hematotoxicity and genotoxicity of Bt spore-crystals genetically modified to express Cry1Ac individually, administered orally (p.o.) or with a single intraperitoneal (i.p.) injection 24 h before euthanasia, to simulate the routes of mucosal and parenteral immunizations in Swiss mice. Blood samples were used to perform hemogram, and bone marrow was used for the micronucleus test. Cry1Ac presented cytotoxic effects on erythroid lineage in both routes, being more severe in the i.p. route, which also showed genotoxic effects. The greater severity noted in this route, mainly at 6.75 mg/kg, as well as the intermediate effects at 13.5 mg/kg, and the very low hematotoxicity at 27 mg/kg, suggested a possible inverse agonism. The higher immunogenicity for the p.o. route, particularly at 27 mg/kg, suggested that at this dose, Cry 1Ac could potentially be used as a mucosal adjuvant (but not in parenteral immunizations, due to the genotoxic effects observed). This potential should be investigated further, including making an evaluation of the proposed inverse agonism and carrying out cytokine profiling. Full article
(This article belongs to the Section Bacterial Toxins)
Open AccessArticle
New Invertebrate Vectors of Okadaic Acid from the North Atlantic Waters—Portugal (Azores and Madeira) and Morocco
Toxins 2015, 7(12), 5337-5347; https://doi.org/10.3390/toxins7124885
Received: 6 September 2015 / Revised: 16 November 2015 / Accepted: 16 November 2015 / Published: 8 December 2015
Cited by 1 | Viewed by 1921 | PDF Full-text (587 KB) | HTML Full-text | XML Full-text
Abstract
Okadaic acid and its analogues are potent phosphatase inhibitors that cause Diarrheic Shellfish Poisoning (DSP) through the ingestion of contaminated shellfish by humans. This group of toxins is transmitted worldwide but the number of poisoning incidents has declined over the last 20 years [...] Read more.
Okadaic acid and its analogues are potent phosphatase inhibitors that cause Diarrheic Shellfish Poisoning (DSP) through the ingestion of contaminated shellfish by humans. This group of toxins is transmitted worldwide but the number of poisoning incidents has declined over the last 20 years due to legislation and monitoring programs that were implemented for bivalves. In the summer of 2012 and 2013, we collected a total of 101 samples of 22 different species that were made up of benthic and subtidal organisms such echinoderms, crustaceans, bivalves and gastropods from Madeira, São Miguel Island (Azores archipelago) and the northwestern coast of Morocco. The samples were analyzed by UPLC-MS/MS. Our main objective was to detect new vectors for these biotoxins. We can report nine new vectors for these toxins in the North Atlantic: Astropecten aranciacus, Arbacia lixula, Echinaster sepositus, Holothuria sanctori, Ophidiaster ophidianus, Onchidella celtica, Aplysia depilans, Patella spp., and Stramonita haemostoma. Differences in toxin contents among the species were found. Even though low concentrations were detected, the levels of toxins that were present, especially in edible species, indicate the importance of these types of studies. Routine monitoring should be extended to comprise a wider number of vectors other than for bivalves of okadaic acid and its analogues. Full article
Figures

Figure 1

Open AccessArticle
Snake and Spider Toxins Induce a Rapid Recovery of Function of Botulinum Neurotoxin Paralysed Neuromuscular Junction
Toxins 2015, 7(12), 5322-5336; https://doi.org/10.3390/toxins7124887
Received: 23 October 2015 / Revised: 20 November 2015 / Accepted: 30 November 2015 / Published: 8 December 2015
Cited by 11 | Viewed by 2428 | PDF Full-text (3838 KB) | HTML Full-text | XML Full-text
Abstract
Botulinum neurotoxins (BoNTs) and some animal neurotoxins (β-Bungarotoxin, β-Btx, from elapid snakes and α-Latrotoxin, α-Ltx, from black widow spiders) are pre-synaptic neurotoxins that paralyse motor axon terminals with similar clinical outcomes in patients. However, their mechanism of action is different, leading to a [...] Read more.
Botulinum neurotoxins (BoNTs) and some animal neurotoxins (β-Bungarotoxin, β-Btx, from elapid snakes and α-Latrotoxin, α-Ltx, from black widow spiders) are pre-synaptic neurotoxins that paralyse motor axon terminals with similar clinical outcomes in patients. However, their mechanism of action is different, leading to a largely-different duration of neuromuscular junction (NMJ) blockade. BoNTs induce a long-lasting paralysis without nerve terminal degeneration acting via proteolytic cleavage of SNARE proteins, whereas animal neurotoxins cause an acute and complete degeneration of motor axon terminals, followed by a rapid recovery. In this study, the injection of animal neurotoxins in mice muscles previously paralyzed by BoNT/A or /B accelerates the recovery of neurotransmission, as assessed by electrophysiology and morphological analysis. This result provides a proof of principle that, by causing the complete degeneration, reabsorption, and regeneration of a paralysed nerve terminal, one could favour the recovery of function of a biochemically- or genetically-altered motor axon terminal. These observations might be relevant to dying-back neuropathies, where pathological changes first occur at the neuromuscular junction and then progress proximally toward the cell body. Full article
(This article belongs to the Section Animal Venoms)
Figures

Figure 1

Open AccessEditorial
Preface Biological Toxins—Ancient Molecules Posing a Current Threat
Toxins 2015, 7(12), 5320-5321; https://doi.org/10.3390/toxins7124888
Received: 24 November 2015 / Accepted: 3 December 2015 / Published: 8 December 2015
Cited by 3 | Viewed by 1571 | PDF Full-text (133 KB) | HTML Full-text | XML Full-text
Abstract
Based on their characteristics, biological toxins are at the interface of classical biological and chemical agents: for example, ricin and saxitoxin are prohibited substances under both the Chemical Weapons Convention and the Biological Weapons Convention.[...] Full article
Figures

Graphical abstract

Open AccessArticle
Superantigen-Producing Staphylococcus aureus Elicits Systemic Immune Activation in a Murine Wound Colonization Model
Toxins 2015, 7(12), 5308-5319; https://doi.org/10.3390/toxins7124886
Received: 12 October 2015 / Revised: 16 November 2015 / Accepted: 1 December 2015 / Published: 8 December 2015
Cited by 5 | Viewed by 2110 | PDF Full-text (2723 KB) | HTML Full-text | XML Full-text
Abstract
Staphylococcus aureus, the most common cause of wound infection, produces several exotoxins, including superantigens (SAgs). SAgs are the potent activators of the immune system. Given this unique property, we hypothesized that SAgs produced by S. aureus in wounds would have local, as [...] Read more.
Staphylococcus aureus, the most common cause of wound infection, produces several exotoxins, including superantigens (SAgs). SAgs are the potent activators of the immune system. Given this unique property, we hypothesized that SAgs produced by S. aureus in wounds would have local, as well as systemic immunologic effects. We tested our hypothesis using a novel staphylococcal skin wound infection model in transgenic mice expressing HLA-DR3. Skin wounds were left uninfected or colonized with S. aureus strains producing SAgs or an isogenic strain not producing any SAg. Animals with wounds challenged with SAg-producing S. aureus had increased morbidity and lower serum IL-17 levels compared to those challenged with the SAg non-producing S. aureus (p = 0.027 and p = 0.032, respectively). At Day 8 following microbial challenge, compared to mice with uninfected wounds, the proportion of Vβ8+CD4+ T cells was increased, while the proportion of Vβ8+CD8+ T cells was decreased only in the spleens of mice challenged with SAg-producing S. aureus (p < 0.001). No such changes were measured in mice challenged with SAg non-producing S. aureus. Lungs, livers and kidneys from mice challenged with SAg-producing, but not SAg non-producing, S. aureus showed inflammatory changes. Overall, SAg-mediated systemic immune activation in wounds harboring S. aureus may have clinical implications. Full article
(This article belongs to the collection Staphylococcus aureus Toxins)
Figures

Figure 1

Open AccessReview
Alkaloid-Containing Plants Poisonous to Cattle and Horses in Europe
Toxins 2015, 7(12), 5301-5307; https://doi.org/10.3390/toxins7124884
Received: 19 October 2015 / Revised: 17 November 2015 / Accepted: 1 December 2015 / Published: 8 December 2015
Cited by 11 | Viewed by 2390 | PDF Full-text (181 KB) | HTML Full-text | XML Full-text
Abstract
Alkaloids, nitrogen-containing secondary plant metabolites, are of major interest to veterinary toxicology because of their occurrence in plant species commonly involved in animal poisoning. Based on epidemiological data, the poisoning of cattle and horses by alkaloid-containing plants is a relatively common occurrence in [...] Read more.
Alkaloids, nitrogen-containing secondary plant metabolites, are of major interest to veterinary toxicology because of their occurrence in plant species commonly involved in animal poisoning. Based on epidemiological data, the poisoning of cattle and horses by alkaloid-containing plants is a relatively common occurrence in Europe. Poisoning may occur when the plants contaminate hay or silage or when forage alternatives are unavailable. Cattle and horses are particularly at risk of poisoning by Colchicum autumnale (meadow saffron), Conium maculatum (poison hemlock), Datura stramonium (jimson weed), Equisetum palustre (marsh horsetail), Senecio spp. (ragwort and groundsel) and Taxus baccata (European yew). This review of poisonous alkaloid-containing plants describes the distribution of these plants, conditions under which poisoning occurs, active toxic principles involved and subsequent clinical signs observed. Full article
(This article belongs to the collection Toxicity of Natural Alkaloids)
Open AccessReview
Recent Advances for the Detection of Ochratoxin A
Toxins 2015, 7(12), 5276-5300; https://doi.org/10.3390/toxins7124882
Received: 21 September 2015 / Revised: 25 November 2015 / Accepted: 26 November 2015 / Published: 4 December 2015
Cited by 25 | Viewed by 2440 | PDF Full-text (1949 KB) | HTML Full-text | XML Full-text
Abstract
Ochratoxin A (OTA) is one of the mycotoxins secreted by Aspersillus and Penicillium that can easily colonize various grains like coffee, peanut, rice, and maize. Since OTA is a chemically stable compound that can endure the physicochemical conditions of modern food processing, additional [...] Read more.
Ochratoxin A (OTA) is one of the mycotoxins secreted by Aspersillus and Penicillium that can easily colonize various grains like coffee, peanut, rice, and maize. Since OTA is a chemically stable compound that can endure the physicochemical conditions of modern food processing, additional research efforts have been devoted to develop sensitive and cost-effective surveillance solutions. Although traditional chromatographic and immunoassays appear to be mature enough to attain sensitivity up to the regulation levels, alternative detection schemes are still being enthusiastically pursued in an attempt to meet the requirements of rapid and cost-effective detections. Herein, this review presents recent progresses in OTA detections with minimal instrumental usage, which have been facilitated by the development of OTA aptamers and by the innovations in functional nanomaterials. In addition to the introduction of aptamer-based OTA detection techniques, OTA-specific detection principles are also presented, which exclusively take advantage of the unique chemical structure and related physicochemical characteristics. Full article
(This article belongs to the Section Mycotoxins)
Figures

Figure 1

Open AccessReview
Membrane-Binding Mechanism of Clostridium perfringens Alpha-Toxin
Toxins 2015, 7(12), 5268-5275; https://doi.org/10.3390/toxins7124880
Received: 27 October 2015 / Revised: 17 November 2015 / Accepted: 30 November 2015 / Published: 3 December 2015
Cited by 11 | Viewed by 2971 | PDF Full-text (1142 KB) | HTML Full-text | XML Full-text
Abstract
Clostridium perfringens alpha-toxin is a key mediator of gas gangrene, which is a life-threatening infection that manifests as fever, pain, edema, myonecrosis, and gas production. Alpha-toxin possesses phospholipase C and sphingomyelinase activities. The toxin is composed of an N-terminal domain (1–250 aa, [...] Read more.
Clostridium perfringens alpha-toxin is a key mediator of gas gangrene, which is a life-threatening infection that manifests as fever, pain, edema, myonecrosis, and gas production. Alpha-toxin possesses phospholipase C and sphingomyelinase activities. The toxin is composed of an N-terminal domain (1–250 aa, N-domain), which is the catalytic site, and a C-terminal domain (251–370 aa, C-domain), which is the membrane-binding site. Immunization of mice with the C-domain of alpha-toxin prevents the gas gangrene caused by C. perfringens, whereas immunization with the N-domain has no effect. The central loop domain (55–93 aa), especially H….SW84Y85….G, plays an important role in the interaction with ganglioside GM1a. The toxin binds to lipid rafts in the presence of a GM1a/TrkA complex, and metabolites from phosphatidylcholine to diacylglycerol through the enzymatic activity of alpha-toxin itself. These membrane dynamics leads to the activation of endogenous PLCγ-1 via TrkA. In addition, treatment with alpha-toxin leads to the formation of diacylglycerol at membrane rafts in ganglioside-deficient DonQ cells; this in turn triggers endocytosis and cell death. This article summarizes the current the membrane-binding mechanism of alpha-toxin in detail. Full article
Figures

Figure 1

Open AccessReview
The Role of Rho GTPases in Toxicity of Clostridium difficile Toxins
Toxins 2015, 7(12), 5254-5267; https://doi.org/10.3390/toxins7124874
Received: 24 September 2015 / Revised: 18 November 2015 / Accepted: 18 November 2015 / Published: 2 December 2015
Cited by 21 | Viewed by 3384 | PDF Full-text (1061 KB) | HTML Full-text | XML Full-text
Abstract
Clostridium difficile (C. difficile) is the main cause of antibiotic-associated diarrhea prevailing in hospital settings. In the past decade, the morbidity and mortality of C. difficile infection (CDI) has increased significantly due to the emergence of hypervirulent strains. Toxin A (TcdA) [...] Read more.
Clostridium difficile (C. difficile) is the main cause of antibiotic-associated diarrhea prevailing in hospital settings. In the past decade, the morbidity and mortality of C. difficile infection (CDI) has increased significantly due to the emergence of hypervirulent strains. Toxin A (TcdA) and toxin B (TcdB), the two exotoxins of C. difficile, are the major virulence factors of CDI. The common mode of action of TcdA and TcdB is elicited by specific glucosylation of Rho-GTPase proteins in the host cytosol using UDP-glucose as a co-substrate, resulting in the inactivation of Rho proteins. Rho proteins are the key members in many biological processes and signaling pathways, inactivation of which leads to cytopathic and cytotoxic effects and immune responses of the host cells. It is supposed that Rho GTPases play an important role in the toxicity of C. difficile toxins. This review focuses on recent progresses in the understanding of functional consequences of Rho GTPases glucosylation induced by C. difficile toxins and the role of Rho GTPases in the toxicity of TcdA and TcdB. Full article
Figures

Figure 1

Open AccessArticle
Mass Spectrometry-Based Method of Detecting and Distinguishing Type 1 and Type 2 Shiga-Like Toxins in Human Serum
Toxins 2015, 7(12), 5236-5253; https://doi.org/10.3390/toxins7124875
Received: 29 September 2015 / Revised: 28 October 2015 / Accepted: 9 November 2015 / Published: 2 December 2015
Cited by 5 | Viewed by 1764 | PDF Full-text (1202 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Shiga-like toxins (verotoxins) are responsible for the virulence associated with a variety of foodborne bacterial pathogens. Direct detection of toxins requires a specific and sensitive technique. In this study, we describe a mass spectrometry-based method of analyzing the tryptic decapeptides derived from the [...] Read more.
Shiga-like toxins (verotoxins) are responsible for the virulence associated with a variety of foodborne bacterial pathogens. Direct detection of toxins requires a specific and sensitive technique. In this study, we describe a mass spectrometry-based method of analyzing the tryptic decapeptides derived from the non-toxic B subunits. A gene encoding a single protein that yields a set of relevant peptides upon digestion with trypsin was designed. The 15N-labeled protein was prepared by growing the expressing bacteria in minimal medium supplemented with 15NH4Cl. Trypsin digestion of the 15N-labeled protein yields a set of 15N-labeled peptides for use as internal standards to identify and quantify Shiga or Shiga-like toxins. We determined that this approach can be used to detect, quantify and distinguish among the known Shiga toxins (Stx) and Shiga-like toxins (Stx1 and Stx2) in the low attomole range (per injection) in complex media, including human serum. Furthermore, Stx1a could be detected and distinguished from the newly identified Stx1e in complex media. As new Shiga-like toxins are identified, this approach can be readily modified to detect them. Since intact toxins are digested with trypsin prior to analysis, the handling of intact Shiga toxins is minimized. The analysis can be accomplished within 5 h. Full article
Figures

Figure 1

Open AccessArticle
Multi-Toxic Endpoints of the Foodborne Mycotoxins in Nematode Caenorhabditis elegans
Toxins 2015, 7(12), 5224-5235; https://doi.org/10.3390/toxins7124876
Received: 22 September 2015 / Revised: 11 November 2015 / Accepted: 13 November 2015 / Published: 2 December 2015
Cited by 12 | Viewed by 2472 | PDF Full-text (1768 KB) | HTML Full-text | XML Full-text
Abstract
Aflatoxins B1 (AFB1), deoxynivalenol (DON), fumonisin B1 (FB1), T-2 toxin (T-2), and zearalenone (ZEA) are the major foodborne mycotoxins of public health concerns. In the present study, the multiple toxic endpoints of these naturally-occurring mycotoxins were evaluated [...] Read more.
Aflatoxins B1 (AFB1), deoxynivalenol (DON), fumonisin B1 (FB1), T-2 toxin (T-2), and zearalenone (ZEA) are the major foodborne mycotoxins of public health concerns. In the present study, the multiple toxic endpoints of these naturally-occurring mycotoxins were evaluated in Caenorhabditis elegans model for their lethality, toxic effects on growth and reproduction, as well as influence on lifespan. We found that the lethality endpoint was more sensitive for T-2 toxicity with the EC50 at 1.38 mg/L, the growth endpoint was relatively sensitive for AFB1 toxic effects, and the reproduction endpoint was more sensitive for toxicities of AFB1, FB1, and ZEA. Moreover, the lifespan endpoint was sensitive to toxic effects of all five tested mycotoxins. Data obtained from this study may serve as an important contribution to knowledge on assessment of mycotoxin toxic effects, especially for assessing developmental and reproductive toxic effects, using the C. elegans model. Full article
(This article belongs to the Section Mycotoxins)
Figures

Figure 1

Open AccessArticle
MC-LR Exposure Leads to Subfertility of Female Mice and Induces Oxidative Stress in Granulosa Cells
Toxins 2015, 7(12), 5212-5223; https://doi.org/10.3390/toxins7124872
Received: 28 August 2015 / Revised: 17 November 2015 / Accepted: 23 November 2015 / Published: 2 December 2015
Cited by 11 | Viewed by 1842 | PDF Full-text (2410 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Health risk of human exposure to microcystin-leucine arginine (MC-LR) has aroused more and more attention over the past few decades. In the present study, MC-LR was orally administered to female mice at 0, 1, 10 and 40 μg/L for three and six months. [...] Read more.
Health risk of human exposure to microcystin-leucine arginine (MC-LR) has aroused more and more attention over the past few decades. In the present study, MC-LR was orally administered to female mice at 0, 1, 10 and 40 μg/L for three and six months. We found that chronic exposure to MC-LR at environmental levels could stimulate follicle atresia and lead to decreased developmental follicles, accompanied by a reduction of gonadosomatic index (GSI). In line with the irregular gonadal hormone level and estrus cycles, subfertility of female mice was also confirmed by analyzing numbers of litters and pups. The in vitro study suggested that granulosa cells could uptake MC-LR and should be the target of the toxicant. Oxidative stress in granulose cells induced by MC-LR promoted follicle atresia and eventually leads to female subfertility. Full article
(This article belongs to the Special Issue Bioactivity and Toxicity in Marine Cyanobacteria)
Figures

Figure 1

Open AccessReview
Computational Studies of Venom Peptides Targeting Potassium Channels
Toxins 2015, 7(12), 5194-5211; https://doi.org/10.3390/toxins7124877
Received: 15 October 2015 / Revised: 13 November 2015 / Accepted: 20 November 2015 / Published: 1 December 2015
Cited by 8 | Viewed by 2234 | PDF Full-text (3300 KB) | HTML Full-text | XML Full-text
Abstract
Small peptides isolated from the venom of animals are potential scaffolds for ion channel drug discovery. This review article mainly focuses on the computational studies that have advanced our understanding of how various toxins interfere with the function of K+ channels. We [...] Read more.
Small peptides isolated from the venom of animals are potential scaffolds for ion channel drug discovery. This review article mainly focuses on the computational studies that have advanced our understanding of how various toxins interfere with the function of K+ channels. We introduce the computational tools available for the study of toxin-channel interactions. We then discuss how these computational tools have been fruitfully applied to elucidate the mechanisms of action of a wide range of venom peptides from scorpions, spiders, and sea anemone. Full article
(This article belongs to the Special Issue Animal Toxins and Biological Ion Channels)
Figures

Figure 1

Open AccessArticle
Phylloseptin-PBa—A Novel Broad-Spectrum Antimicrobial Peptide from the Skin Secretion of the Peruvian Purple-Sided Leaf Frog (Phyllomedusa Baltea) Which Exhibits Cancer Cell Cytotoxicity
Toxins 2015, 7(12), 5182-5193; https://doi.org/10.3390/toxins7124878
Received: 14 October 2015 / Revised: 9 November 2015 / Accepted: 23 November 2015 / Published: 1 December 2015
Cited by 12 | Viewed by 3274 | PDF Full-text (2195 KB) | HTML Full-text | XML Full-text
Abstract
Antimicrobial peptides from amphibian skin secretion display remarkable broad-spectrum antimicrobial activity and are thus promising for the discovery of new antibiotics. In this study, we report a novel peptide belonging to the phylloseptin family of antimicrobial peptides, from the skin secretion of the [...] Read more.
Antimicrobial peptides from amphibian skin secretion display remarkable broad-spectrum antimicrobial activity and are thus promising for the discovery of new antibiotics. In this study, we report a novel peptide belonging to the phylloseptin family of antimicrobial peptides, from the skin secretion of the purple-sided leaf frog, Phyllomedusa baltea, which was named Phylloseptin-PBa. Degenerate primers complementary to putative signal peptide sites of frog skin peptide precursor-encoding cDNAs were designed to interrogate a skin secretion-derived cDNA library from this frog. Subsequently, the peptide was isolated and identified using reverse phase HPLC and MS/MS fragmentation. The synthetic replicate was demonstrated to have activity against S. aureus, E. coli and C. albicans at concentrations of 8, 128 and 8 mg/L, respectively. In addition, it exhibited anti-proliferative activity against the human cancer cell lines, H460, PC3 and U251MG, but was less active against a normal human cell line (HMEC). Furthermore, a haemolysis assay was performed to assess mammalian cell cytotoxicity of Phylloseptin-PBa. This peptide contained a large proportion of α-helical domain, which may explain its antimicrobial and anticancer activities. Full article
(This article belongs to the Special Issue Venomics, Venom Proteomics and Venom Transcriptomics)
Figures

Figure 1

Open AccessArticle
Risk Assessment of Deoxynivalenol by Revisiting Its Bioavailability in Pig and Rat Models to Establish Which Is More Suitable
Toxins 2015, 7(12), 5167-5181; https://doi.org/10.3390/toxins7124873
Received: 16 August 2015 / Revised: 26 October 2015 / Accepted: 18 November 2015 / Published: 1 December 2015
Cited by 5 | Viewed by 1922 | PDF Full-text (1037 KB) | HTML Full-text | XML Full-text
Abstract
Due to its toxic properties, high stability, and prevalence, the presence of deoxynivalenol (DON) in the food chain is a major threat to food safety and therefore a health risk for both humans and animals. In this study, experiments were carried out with [...] Read more.
Due to its toxic properties, high stability, and prevalence, the presence of deoxynivalenol (DON) in the food chain is a major threat to food safety and therefore a health risk for both humans and animals. In this study, experiments were carried out with sows and female rats to examine the kinetics of DON after intravenous and oral administration at 100 µg/kg of body weight. After intravenous administration of DON in pigs, a two-compartment model with rapid initial distribution (0.030 ± 0.019 h) followed by a slower terminal elimination phase (1.53 ± 0.54 h) was fitted to the concentration profile of DON in pig plasma. In rats, a short elimination half-life (0.46 h) and a clearance of 2.59 L/h/kg were estimated by sparse sampling non-compartmental analysis. Following oral exposure, DON was rapidly absorbed and reached maximal plasma concentrations (Cmax) of 42.07 ± 8.48 and 10.44 ± 5.87 µg/L plasma after (tmax) 1.44 ± 0.52 and 0.17 h in pigs and rats, respectively. The mean bioavailability of DON was 70.5% ± 25.6% for pigs and 47.3% for rats. In the framework of DON risk assessment, these two animal models could be useful in an exposure scenario in two different ways because of their different bioavailability. Full article
(This article belongs to the Section Mycotoxins)
Figures

Figure 1

Open AccessArticle
Interaction of Citrinin with Human Serum Albumin
Toxins 2015, 7(12), 5155-5166; https://doi.org/10.3390/toxins7124871
Received: 19 October 2015 / Revised: 22 November 2015 / Accepted: 25 November 2015 / Published: 1 December 2015
Cited by 14 | Viewed by 2253 | PDF Full-text (1492 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Citrinin (CIT) is a mycotoxin produced by several Aspergillus, Penicillium, and Monascus species. CIT occurs worldwide in different foods and drinks and causes health problems for humans and animals. Human serum albumin (HSA) is the most abundant plasma protein in human [...] Read more.
Citrinin (CIT) is a mycotoxin produced by several Aspergillus, Penicillium, and Monascus species. CIT occurs worldwide in different foods and drinks and causes health problems for humans and animals. Human serum albumin (HSA) is the most abundant plasma protein in human circulation. Albumin forms stable complexes with many drugs and xenobiotics; therefore, HSA commonly plays important role in the pharmacokinetics or toxicokinetics of numerous compounds. However, the interaction of CIT with HSA is poorly characterized yet. In this study, the complex formation of CIT with HSA was investigated using fluorescence spectroscopy and ultrafiltration techniques. For the deeper understanding of the interaction, thermodynamic, and molecular modeling studies were performed as well. Our results suggest that CIT forms stable complex with HSA (logK ~ 5.3) and its primary binding site is located in subdomain IIA (Sudlow’s Site I). In vitro cell experiments also recommend that CIT-HSA interaction may have biological relevance. Finally, the complex formations of CIT with bovine, porcine, and rat serum albumin were investigated, in order to test the potential species differences of CIT-albumin interactions. Full article
(This article belongs to the Section Mycotoxins)
Figures

Figure 1

Open AccessArticle
Assimilation, Accumulation, and Metabolism of Dinophysistoxins (DTXs) and Pectenotoxins (PTXs) in the Several Tissues of Japanese Scallop Patinopecten yessoensis
Toxins 2015, 7(12), 5141-5154; https://doi.org/10.3390/toxins7124870
Received: 15 October 2015 / Revised: 16 November 2015 / Accepted: 17 November 2015 / Published: 1 December 2015
Cited by 9 | Viewed by 1984 | PDF Full-text (1117 KB) | HTML Full-text | XML Full-text
Abstract
Japanese scallops, Patinopecten yessoensis, were fed with the toxic dinoflagellate Dinophysis fortii to elucidate the relative magnitude of assimilation, accumulation, and metabolism of diarrhetic shellfish toxins (DSTs) and pectenotoxins (PTXs). Three individual scallops were separately exposed to cultured D. fortii for [...] Read more.
Japanese scallops, Patinopecten yessoensis, were fed with the toxic dinoflagellate Dinophysis fortii to elucidate the relative magnitude of assimilation, accumulation, and metabolism of diarrhetic shellfish toxins (DSTs) and pectenotoxins (PTXs). Three individual scallops were separately exposed to cultured D. fortii for four days. The average cell number of D. fortii assimilated by each individual scallop was 7.7 × 105. Dinophysistoxin-1 (DTX1), pectenotoxin-2 (PTX2) and their metabolites were analyzed by liquid chromatography tandem mass spectrometry (LC/MS/MS) and the toxin content in individual tissues (digestive gland, adductor muscle, gill, gonad, mantle, and the others), feces and the seawater medium were quantified. Toxins were almost exclusively accumulated in the digestive gland with only low levels being detected in the gills, mantles, gonads, and adductor muscles. DTX1 and PTX2 were the dominant toxins in the D. fortii cells fed to the scallops, whereas the dominant toxins detected in the digestive gland of scallops were PTX6 and esterified acyl-O-DTX1 (DTX3). In other tissues PTX2 was the dominant toxin observed. The ratio of accumulated to assimilated toxins was 21%–39% and 7%–23% for PTXs and DTXs respectively. Approximately 54%–75% of PTX2 and 52%–70% of DTX1 assimilated by the scallops was directly excreted into the seawater mainly without metabolic transformation. Full article
(This article belongs to the collection Marine and Freshwater Toxins)
Figures

Figure 1

Open AccessArticle
Temporal Variation and Association of Aflatoxin B1 Albumin-Adduct Levels with Socio-Economic and Food Consumption Factors in HIV Positive Adults
Toxins 2015, 7(12), 5129-5140; https://doi.org/10.3390/toxins7124868
Received: 7 August 2015 / Revised: 17 November 2015 / Accepted: 19 November 2015 / Published: 30 November 2015
Cited by 2 | Viewed by 1972 | PDF Full-text (611 KB) | HTML Full-text | XML Full-text
Abstract
The association between aflatoxin exposure and alteration in immune responses observed in humans suggest that aflatoxin could suppress the immune system and work synergistically with HIV to increase disease severity and progression to AIDS. No longitudinal study has been conducted to assess exposure [...] Read more.
The association between aflatoxin exposure and alteration in immune responses observed in humans suggest that aflatoxin could suppress the immune system and work synergistically with HIV to increase disease severity and progression to AIDS. No longitudinal study has been conducted to assess exposure to aflatoxin (AF) among HIV positive individuals. We examined temporal variation in AFB1 albumin adducts (AF-ALB) in HIV positive Ghanaians, and assessed the association with socioeconomic and food consumption factors. We collected socioeconomic and food consumption data for 307 HIV positive antiretroviral naive adults and examined AF-ALB levels at recruitment (baseline) and at six (follow-up 1) and 12 (follow-up 2) months post-recruitment, by age, gender, socioeconomic status (SES) and food consumption patterns. Generalized linear models were used to examine the influence of socioeconomic and food consumption factors on changes in AF-ALB levels over the study period, adjusting for other covariates. AF-ALB levels (pg/mg albumin) were lower at baseline (mean AF-ALB: 14.9, SD: 15.9), higher at six months (mean AF-ALB: 23.3, SD: 26.6), and lower at 12 months (mean AF-ALB: 15.3, SD: 15.4). Participants with the lowest SES had the highest AF-ALB levels at baseline and follow up-2 compared with those with higher SES. Participants who bought less than 20% of their food and who stored maize for less than two months had lower AF-ALB levels. In the adjusted models, there was a statistically significant association between follow up time and season (dry or rainy season) on AF-ALB levels over time (p = 0.04). Asymptomatic HIV-positive Ghanaians had high plasma AF-ALB levels that varied according to season, socioeconomic status, and food consumption patterns. Steps need to be taken to ensure the safety and security of the food supply for the population, but in particular for the most vulnerable groups such as HIV positive people. Full article
(This article belongs to the Special Issue Mycotoxins and Human Diseases 2015)
Figures

Figure 1

Open AccessArticle
Biological and Enzymatic Characterization of Proteases from Crude Venom of the Ant Odontomachus bauri
Toxins 2015, 7(12), 5114-5128; https://doi.org/10.3390/toxins7124869
Received: 14 August 2015 / Revised: 30 September 2015 / Accepted: 9 October 2015 / Published: 30 November 2015
Cited by 5 | Viewed by 2324 | PDF Full-text (2225 KB) | HTML Full-text | XML Full-text
Abstract
Hymenoptera venoms constitute an interesting source of natural toxins that may lead to the development of novel therapeutic agents. The present study investigated the enzymatic and biological characteristics of the crude venom of the ant Odontomachus bauri. Its crude venom presents several [...] Read more.
Hymenoptera venoms constitute an interesting source of natural toxins that may lead to the development of novel therapeutic agents. The present study investigated the enzymatic and biological characteristics of the crude venom of the ant Odontomachus bauri. Its crude venom presents several protein bands, with higher staining for six proteins with gelatinolytic activity (17, 20, 26, 29, 43 and 48 kDa). The crude venom showed high proteolytic activity on azocasein at optimal pH 8.0 and 37 °C. In the presence of protease inhibitors as aprotinin, leupeptin and EDTA, the azocaseinolytic activity was reduced by 45%, 29% and 9%, respectively, suggesting that the enzymes present in the crude venom belong to the three classes of proteases, with the serine proteases in greater intensity. The crude venom degraded the fibrinogen α-chain faster than the β-chain, while the fibrinogen γ-chain remained unchanged. In biological assays, O. bauri venom showed hemolytic and coagulant activity in vitro, and defibrinating activity in vivo. In addition, the venom showed antimicrobial activity against Staphylococcus aureus and Escherichia coli as well as antiparasitic activity on Toxoplasma gondii infection in vitro. In that sense, this study sheds perspectives for pharmacological applications of O. bauri venom enzymes. Full article
(This article belongs to the Special Issue Arthropod Venoms)
Figures

Figure 1

Open AccessArticle
A Venom Gland Extracellular Chitin-Binding-Like Protein from Pupal Endoparasitoid Wasps, Pteromalus Puparum, Selectively Binds Chitin
Toxins 2015, 7(12), 5098-5113; https://doi.org/10.3390/toxins7124867
Received: 13 October 2015 / Revised: 12 November 2015 / Accepted: 17 November 2015 / Published: 30 November 2015
Cited by 4 | Viewed by 1941 | PDF Full-text (3271 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Chitin-binding proteins (CBPs) are present in many species and they act in a variety of biological processes. We analyzed a Pteromalus puparum venom apparatus proteome and transcriptome and identified a partial gene encoding a possible CBP. Here, we report cloning a full-length cDNA [...] Read more.
Chitin-binding proteins (CBPs) are present in many species and they act in a variety of biological processes. We analyzed a Pteromalus puparum venom apparatus proteome and transcriptome and identified a partial gene encoding a possible CBP. Here, we report cloning a full-length cDNA of a sequence encoding a chitin-binding-like protein (PpCBP) from P. puparum, a pupal endoparasitoid of Pieris rapae. The cDNA encoded a 96-amino-acid protein, including a secretory signal peptide and a chitin-binding peritrophin-A domain. Phylogenetic analysis of chitin binding domains (CBDs) of cuticle proteins and peritrophic matrix proteins in selected insects revealed that the CBD of PpCBP clustered with the CBD of Nasonia vitripennis. The PpCBP is specifically expressed in the venom apparatus of P. puparum, mostly in the venom gland. PpCBP expression was highest at day one after adult eclosion and much lower for the following five days. We produced a recombinant PpCBP and binding assays showed the recombinant protein selectively binds chitin but not cellulose in vitro. We infer that PpCBP serves a structural role in the venom reservoir, or may be injected into the host to help wound healing of the host exoskeleton. Full article
(This article belongs to the Special Issue Arthropod Venoms)
Figures

Figure 1

Toxins EISSN 2072-6651 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top