General biological effects of TCDD in laboratory animals.

Filamentous fungi that contaminate livestock feeds and human food supply often produce toxigenic secondary metabolites known as mycotoxins. Among the hundreds of known mycotoxins, aflatoxins, deoxynivalenol, fumonisins, ochratoxin A and zearalenone are considered the most commercially important. Intense research on these mycotoxins, especially aflatoxin, has resulted in the development of 'biomarkers' used to link exposure to disease risk. In the case of aflatoxin this effort has led to the discovery of both exposure and mechanism-based biomarkers, which have proven essential for understanding aflatoxin's potential for causing disease in humans, including subtle effects on growth and immune response. Fumonisin biomarkers have also been used extensively in farm and laboratory animals to study the fumonisin-induced disruption of cellular and systemic physiology which leads to disease. This review summarises the status of mycotoxin biomarker development in humans and animals for the commercially important mycotoxins. Since the fungi responsible for the production of these mycotoxins are often endophytes that infect and colonise living plant tissues, accumulation of mycotoxins in the plant tissues may at times be associated with development of plant disease symptoms. The presence of mycotoxins, even in the absence of disease symptoms, may still have subtle biological effects on the physiology of plants. This review examines the question of whether or not the knowledge gained from mechanistic studies and development of biomarkers in animal and human systems is transferable to the study of mycotoxin effects on plant systems. Thus far, fumonisin has proven amenable to development of mechanism-based biomarkers to study maize seedling disease caused by the fumonisin producer, Fusarium verticillioides. Expanding our knowledge of mechanisms of toxicity and the overt and subtle effects on animal, human, and plant systems through the identification and validation of biomarkers will further our ability to monitor and limit the damage and economic impact of mycotoxins.

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Study of toxicity and peculiarities of biological effects of nanocomposite pectin-Ag: results of a subchronic experiment

Токсикологический вестник ◽

10.36946/0869-7922-2021-29-5-25-33 ◽

2021 ◽

Vol 29 (5) ◽

pp. 25-33

Author(s):

Vadzim Michailovich Vasilkevich ◽

Ruslan Valerievich Bogdanov ◽

Ksenia Sergeevna Gilevskaya ◽

Victoria Igorevna Kulikouskaya

Keyword(s):

Biological Effects ◽

Experimental Studies ◽

Laboratory Animals ◽

Intragastric Administration ◽

Pectin Content ◽

Target Organs ◽

Toxicological Studies ◽

Threshold Doses ◽

20 Nm ◽

Dose Dependent

Introduction. Nanocomposites synthesized by the “green chemistry” method do not contain toxic chemicals (reducing agents and organic solvents) as carriers and/or stabilizing shells. One of the representatives of this group of materials are nanocomposites based on silver, which are increasingly used in medical practice, veterinary medicine, and in some other fields. Material and methods. The nanocomposite is Ag0 nanoparticles coated with a highly methoxylated pectin shell. The concentration of Ag0 nanoparticles in the hydrosol of the pectin-Ag nanocomposite is 1.65 mmol/l, and the pectin content is 7.5 mg/ml. The size of the synthesized pectin-Ag nanocomposite is ~20-30 nm, more than 90% of the particles have a diameter of less than 20 nm, the value of the ξ-potential is 45.3 ± 0.7 mV. Toxicological studies were carried out on outbred rats. The main goal of the research was to study the toxic effects of the pectin-Ag nanocomposite in a subchronic experiment (90 days). At the end of the experiment, a complex of behavioral and clinical and laboratory parameters was determined, which made it possible to assess the biological effect of the nanocomposite on animals. The research results were statistically processed. Results. With subchronic intragastric administration of the pectin-Ag nanocomposite to laboratory animals (rats) for 3 months at doses of 50, 500, and 5000 mg/kg, it was found that the nanocomposite exhibits a dose-dependent general toxic effect with critical target organs - the liver and spleen and the main biochemical markers of toxicity effect - aminotransferase, alkaline phosphatase and lactate dehydrogenase. Conclusion. Experimental studies have made it possible to substantiate the threshold doses of the hydrosol of the pectin-Ag nanocomposite for the intragastric route of intake.

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Cocoa Flavanols: Natural Agents with Attenuating Effects on Metabolic Syndrome Risk Factors

Nutrients ◽

10.3390/nu11040751 ◽

2019 ◽

Vol 11 (4) ◽

pp. 751 ◽

Cited By ~ 12

Author(s):

Maria Jaramillo Flores

Keyword(s):

Risk Factors ◽

Metabolic Syndrome ◽

Molecular Mechanisms ◽

Biological Effects ◽

Antioxidant Properties ◽

Laboratory Animals ◽

Protective Effects ◽

Plant Metabolites ◽

Secondary Plant Metabolites

The interest in cacao flavanols is still growing, as bioactive compounds with potential benefits in the prevention of chronic diseases associated with inflammation, oxidative stress and metabolic disorders. Several analytical methodologies support that the flavanols in cacao-derived products can be absorbed, have bioactive properties, and thus can be responsible for their beneficial effects on human health. However, it must be considered that their biological actions and underlying molecular mechanisms will depend on the concentrations achieved in their target tissues. Based on the antioxidant properties of cacao flavanols, this review focuses on recent advances in research regarding their potential to improve metabolic syndrome risk factors. Additionally, it has included other secondary plant metabolites that have been investigated for their protective effects against metabolic syndrome. Studies using laboratory animals or human subjects represent strong available evidence for biological effects of cacao flavanols. Nevertheless, in vitro studies are also included to provide an overview of these phytochemical mechanisms of action. Further studies are needed to determine if the main cacao flavanols or their metabolites are responsible for the observed health benefits and which are their precise molecular mechanisms.

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Plasmid Vectors Encoding Cholera Toxin or the Heat-Labile Enterotoxin from Escherichia coli Are Strong Adjuvants for DNA Vaccines

Journal of Virology ◽

10.1128/jvi.76.9.4536-4546.2002 ◽

2002 ◽

Vol 76 (9) ◽

pp. 4536-4546 ◽

Cited By ~ 58

Author(s):

Joshua Arrington ◽

Ralph P. Braun ◽

Lichun Dong ◽

Deborah H. Fuller ◽

Michael D. Macklin ◽

...

Keyword(s):

Escherichia Coli ◽

Cholera Toxin ◽

Dna Vaccines ◽

Biological Effects ◽

Laboratory Animals ◽

Plasmid Vectors ◽

Cytokine Responses ◽

Heat Labile ◽

B Subunits ◽

Adjuvant Effects

ABSTRACT Two plasmid vectors encoding the A and B subunits of cholera toxin (CT) and two additional vectors encoding the A and B subunits of the Escherichia coli heat-labile enterotoxin (LT) were evaluated for their ability to serve as genetic adjuvants for particle-mediated DNA vaccines administered to the epidermis of laboratory animals. Both the CT and the LT vectors strongly augmented Th1 cytokine responses (gamma interferon [IFN-γ]) to multiple viral antigens when codelivered with DNA vaccines. In addition, Th2 cytokine responses (interleukin 4 [IL-4]) were also augmented by both sets of vectors, with the effects of the LT vectors on IL-4 responses being more antigen dependent. The activities of both sets of vectors on antibody responses were antigen dependent and ranged from no effect to sharp reductions in the immunoglobulin G1 (IgG1)-to-IgG2a ratios. Overall, the LT vectors exhibited stronger adjuvant effects in terms of T-cell responses than did the CT vectors, and this was correlated with the induction of greater levels of cyclic AMP by the LT vectors following vector transfection into cultured cells. The adjuvant effects observed in vivo were due to the biological effects of the encoded proteins and not due to CpG motifs in the bacterial genes. Interestingly, the individual LT A and B subunit vectors exhibited partial adjuvant activity that was strongly influenced by the presence or absence of signal peptide coding sequences directing the encoded subunit to either intracellular or extracellular locations. Particle-mediated delivery of either the CT or LT adjuvant vectors in rodents and domestic pigs was well tolerated, suggesting that bacterial toxin-based genetic adjuvants may be a safe and effective strategy to enhance the potency of both prophylactic and therapeutic DNA vaccines for the induction of strong cellular immunity.

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Biological effects of high strength electric fields on small laboratory animals. Interim progress report, March 9, 1976--September 8, 1976

10.2172/7122215 ◽

1976 ◽

Author(s):

R.D. Phillips ◽

W.T. Kaune ◽

J.R. Decker ◽

D.L. Hjeresen

Keyword(s):

Electric Fields ◽

Biological Effects ◽

High Strength ◽

Progress Report ◽

Laboratory Animals ◽

Small Laboratory

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Intravenous Lipid Emulsions in the Prevention and Treatment of Liver Disease in Intestinal Failure

Nutrients ◽

10.3390/nu13030895 ◽

2021 ◽

Vol 13 (3) ◽

pp. 895

Author(s):

Fedja A. Rochling

Keyword(s):

Liver Disease ◽

Fish Oil ◽

Biological Effects ◽

Case Reports ◽

Intestinal Failure ◽

Adult Patients ◽

Laboratory Animals ◽

Lipid Emulsions ◽

Prevention And Treatment

The development of intestinal failure-associated liver disease (IFALD) in pediatric and adult patients on parenteral nutrition is usually multifactorial in nature due to nutritional and non-nutritional causes. The role of lipid therapy as a contributing cause is well-established with the pathophysiological pathways now better understood. The review focuses on risk factors for IFALD development, biological effects of lipids, lipid emulsions and the mechanisms of lipid toxicity observed in laboratory animals followed by a synopsis of clinical studies in pediatric and adult patients. The introduction of fish oil-based lipid emulsions that provide partial or complete lipid replacement therapy has resulted in resolution of IFALD that had been associated with soybean oil-based therapy. Based on case reports and cohort studies in pediatric and adult patients who were at risk or developed overt liver disease, we now have more evidence that an early switch to partial or complete fish oil–based lipid therapy should be implemented in order to successfully halt and reverse IFALD.

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Biological effects and assessment of acute toxicity of anticoagulants extracted from plants

Medical Science And Education Of Ural ◽

10.36361/1814-8999-2020-21-4-27-29 ◽

2020 ◽

Vol 21 (4) ◽

pp. 27-29

Author(s):

E. P. Kalinin ◽

◽

N. N. Buslaeva ◽

D. I. Boyarintsev ◽

◽

...

Keyword(s):

Acute Toxicity ◽

Biological Effect ◽

Leaf Extract ◽

Biological Effects ◽

Inhibitory Effect ◽

Anticoagulant Effect ◽

Laboratory Animals ◽

Plasma Coagulation ◽

Direct Acting

The aim of the study – was to study the biological effects and assess acute toxicity in an in vivo experimental study when injecting plant-derived effectors with an anticoagulant effect to laboratory animals. Materials and methods. As the studied effectors, plant anticoagulants obtained from the leaves of blueberry (Vaccinium myrtillus) and peloid, which were obtained in the previous studies, were used. The biological effect of effectors was evaluated by indicators characterizing coagulation and platelet hemostasis when administered to laboratory animals. Acute toxicity was assessed by the survival rate of animals after administration of effectors. Results. Blueberry leaf extract demonstrated an inhibitory effect on the development of reactions of the internal pathway of plasma coagulation and ADP – induced platelet aggregation. The effector obtained from sapropel significantly inhibits both plasma coagulation and platelet reactions. None of the effectors showed acute toxicity. Conclusion. As a result of this study, we consider the most promising peptide for further study, derived from peloid, as a promising direct-acting anticoagulant that affects the final pathway of plasma coagulation. The anticoagulant from blueberry leaves did not demonstrate the expected activity in the in vivo experiment, presumably due to the presence of impurities that neutralize its anticoagulant effect, and needs additional purification and evaluation.

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Larvicidal activity of the water extract of Moringa oleifera seeds against Aedes aegypti and its toxicity upon laboratory animals

Anais da Academia Brasileira de Ciências ◽

10.1590/s0001-37652009000200007 ◽

2009 ◽

Vol 81 (2) ◽

pp. 207-216 ◽

Cited By ~ 24

Author(s):

Paulo M.P. Ferreira ◽

Ana F.U. Carvalho ◽

Davi F. Farias ◽

Nara G. Cariolano ◽

Vânia M.M. Melo ◽

...

Keyword(s):

Aedes Aegypti ◽

Larvicidal Activity ◽

Moringa Oleifera ◽

Biological Effects ◽

Water Extract ◽

Laboratory Animals ◽

Egg Hatching ◽

Lc50 Value ◽

Low Toxicity ◽

Toxic Potential

In this work, biological effects of the water extract of Moringa oleifera seeds (WEMOS) were assessed on eggs and 3rd instar larvae of Aedes aegypti and on its toxicity upon laboratory animals (Daphnia magna, mice and rats). Crude WEMOS showed a LC50 value of 1260µg/mL, causing 99.2 ± 2.9% larvae mortality within 24 h at 5200µg/mL, though this larvicidal activity has been lost completely at 80ºC/10 min. WEMOS did not demonstrate capacity to prevent egg hatching. After extensive dialyses of the crude WEMOS into watersoluble dialyzable (DF) and nondyalizable (NDF) fractions, only DF maintained its efficacy to kill larvae. Acute toxicity evaluations on daphnids (EC50 of 188.7µg/mL) and mice (LD50 of 446.5 mg/kg body weight) pointed out to low toxicity. Despite the thymus hypertrophy, WEMOS revealed to be harmless in orally and subacutelytreated rats. In conclusion, WEMOS has thermostable bioactive compounds against Ae. aegypti larvae with apparent molecular mass lower than 12 kDa and moderately toxic potential.

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