The Use of Biomarkers as Alternatives to Current Animal Tests on Food Chemicals

1998 ◽  
Vol 26 (4) ◽  
pp. 421-480
Author(s):  
Krys Bottrill
Keyword(s):  
Animal Studies ◽  
Developmental Toxicity ◽  
Reproductive Toxicity ◽  
In Vitro Test ◽  
Animal Testing ◽  
Dietary Biomarkers ◽  
Recent Developments ◽  
Mechanistic Basis ◽  
The Three Rs

Recent developments in biomarkers relating to the interrelationship of diet, disease and health were surveyed. Most emphasis was placed on biomarkers of deleterious effects, since these are of greatest relevance to the subject of this review. The area of greatest activity was found to be that relating to biomarkers of mutagenic, genotoxic and carcinogenic effects. This is also one of the major areas of concern in considerations of the beneficial and deleterious effects of dietary components, and also the area in which regulatory testing requires studies of the longest duration. A degree of progress has also been made in the identification and development of biomarkers relating to certain classes of target organ toxicity. Biomarkers for other types of toxicity, such as immunotoxicity, neurotoxicity, reproductive toxicity and developmental toxicity, are less developed, and further investigation in these areas is required before a comprehensive biomarker strategy can be established. A criticism that recurs constantly in the biomarker literature is the lack of standardisation in the methods used, and the lack of reference standards for the purposes of validation and quality control. It is encouraging to note the growing acknowledgement of the need for validation of biomarkers and biomarker assays. Some validation studies have already been initiated. This review puts forward proposals for criteria to be used in biomarker validation. More discussion on this subject is required. It is concluded that the use of biomarkers can, in some cases, facilitate the implementation of the Three Rs with respect to the testing of food chemicals and studies on the effects of diet on health. The greatest potential is seen to be in the refinement of animal testing, in which biomarkers could serve as early and sensitive endpoints, in order to reduce the duration of the studies and also reduce the number of animals required. Biomarkers could also contribute to establishing a mechanistic basis for in vitro test systems and to facilitating their validation and acceptance. Finally, the increased information that could result from the incorporation of biomarker determinations into population studies could reduce the need for supplementary animal studies. This review makes a number of recommendations concerning the prioritisation of future activities on dietary biomarkers in relation to the Three Rs. It is emphasised, however, that further discussions will be required among toxicologists, epidemiologists and others researching the relationship between diet and health.

scholarly journals Platelet-Rich Plasma: New Performance Understandings and Therapeutic Considerations in 2020

2020 ◽  
Author(s):  
Peter Everts ◽  
Kentaro Onishi ◽  
Prathap Jayaram ◽  
José Fábio Lana ◽  
and Kenneth Mautner
Keyword(s):  
Tissue Repair ◽  
Animal Studies ◽  
Platelet Rich Plasma ◽  
Unmet Need ◽  
Treatment Protocols ◽  
Rehabilitation Protocols ◽  
Recent Developments ◽  
Treatment Plans ◽  
New Research

Emerging autologous cellular therapies that utilize platelet-rich plasma (PRP) applications have the potential to play adjunctive roles in a variety of regenerative medicine treatment plans. There is a global unmet need for tissue repair strategies to treat musculoskeletal (MSK) and spinal disorders, osteoarthritis (OA), and patients with chronic complex and recalcitrant wounds. PRP therapy is based on the fact that platelet growth factors (PGFs) support the three phases of wound healing and repair cascade (inflammation, proliferation, remodeling). Many different PRP formulations have been evaluated, originating from human, in vitro, and animal studies. However, recommendations from in vitro and animal research often lead to different clinical outcomes because it is difficult to translate non-clinical study outcomes and methodology recommendations to human clinical treatment protocols. In recent years, progress has been made in understanding PRP technology and the concepts for bioformulation, and new research directives and new indications have been suggested. In this review, we will discuss recent developments regarding PRP preparation and composition regarding platelet dosing, leukocyte activities concerning innate and adaptive immunomodulation, serotonin (5-HT) effects and pain killing. Furthermore, we discuss PRP mechanisms related to inflammation and angiogenesis in tissue repair and regenerative processes. Lastly, we will review the effect of certain drugs on PRP activity, and the combination of PRP and rehabilitation protocols.

scholarly journals 3D kidney organoids for bench-to-bedside translation

2020 ◽  
Author(s):  
Navin Gupta✉ ◽  
Emre Dilmen ◽  
Ryuji Morizane
Keyword(s):  
Collecting Duct ◽  
Developmental Toxicity ◽  
Human Kidney ◽  
Great Promise ◽  
Duct Systems ◽  
Recent Developments ◽  
Induced Pluripotent ◽  
Kidney Organoids

Abstract The kidneys are essential organs that filter the blood, removing urinary waste while maintaining fluid and electrolyte homeostasis. Current conventional research models such as static cell cultures and animal models are insufficient to grasp the complex human in vivo situation or lack translational value. To accelerate kidney research, novel research tools are required. Recent developments have allowed the directed differentiation of induced pluripotent stem cells to generate kidney organoids. Kidney organoids resemble the human kidney in vitro and can be applied in regenerative medicine and as developmental, toxicity, and disease models. Although current studies have shown great promise, challenges remain including the immaturity, limited reproducibility, and lack of perfusable vascular and collecting duct systems. This review gives an overview of our current understanding of nephrogenesis that enabled the generation of kidney organoids. Next, the potential applications of kidney organoids are discussed followed by future perspectives. This review proposes that advancement in kidney organoid research will be facilitated through our increasing knowledge on nephrogenesis and combining promising techniques such as organ-on-a-chip models.

scholarly journals Platelet-Rich Plasma: New Performance Understandings and Therapeutic Considerations in 2020

2020 ◽  
Vol 21 (20) ◽  
pp. 7794
Author(s):  
Peter Everts ◽  
Kentaro Onishi ◽  
Prathap Jayaram ◽  
José Fábio Lana ◽  
Kenneth Mautner
Keyword(s):  
Tissue Repair ◽  
Animal Studies ◽  
Platelet Rich Plasma ◽  
Unmet Need ◽  
Treatment Protocols ◽  
Rehabilitation Protocols ◽  
Recent Developments ◽  
Treatment Plans ◽  
New Research

Emerging autologous cellular therapies that utilize platelet-rich plasma (PRP) applications have the potential to play adjunctive roles in a variety of regenerative medicine treatment plans. There is a global unmet need for tissue repair strategies to treat musculoskeletal (MSK) and spinal disorders, osteoarthritis (OA), and patients with chronic complex and recalcitrant wounds. PRP therapy is based on the fact that platelet growth factors (PGFs) support the three phases of wound healing and repair cascade (inflammation, proliferation, remodeling). Many different PRP formulations have been evaluated, originating from human, in vitro, and animal studies. However, recommendations from in vitro and animal research often lead to different clinical outcomes because it is difficult to translate non-clinical study outcomes and methodology recommendations to human clinical treatment protocols. In recent years, progress has been made in understanding PRP technology and the concepts for bioformulation, and new research directives and new indications have been suggested. In this review, we will discuss recent developments regarding PRP preparation and composition regarding platelet dosing, leukocyte activities concerning innate and adaptive immunomodulation, serotonin (5-HT) effects, and pain killing. Furthermore, we discuss PRP mechanisms related to inflammation and angiogenesis in tissue repair and regenerative processes. Lastly, we will review the effect of certain drugs on PRP activity, and the combination of PRP and rehabilitation protocols.

Dialogue and Collaboration: A Personal View on Laboratory Animal Welfare Developments in General, and on ECVAM's First Decade in Particular

2002 ◽  
Vol 30 (2_suppl) ◽  
pp. 207-210 ◽  
Author(s):  
Herman B.W.M. Koëter
Keyword(s):  
National Level ◽  
In Vitro Tests ◽  
Practical Application ◽  
Animal Testing ◽  
Validation Process ◽  
Personal View ◽  
Ld50 Test ◽  
The Three Rs ◽  
Regulatory Acceptance

A personal view is presented on progress made during the last 25 years in applying the Three Rs ( reduction, refinement, replacement) to animal testing in regulatory toxicology, with an emphasis on “good moments” (for example, international workshops on the principles and practical application of the validation process and on regulatory acceptance) and “not-so-good moments” (for example, the time taken to accept alternatives to the LD50 test and to accept in vitro tests for skin absorption as OECD Test Guidelines). The importance of dialogue and cooperation between international coordinating centres and scientific activities at the national level is stressed, as exemplified by the work of ECVAM during its first decade.

scholarly journals Replacement Strategies for Animal Studies in Inhalation Testing

Sci ◽  
2021 ◽  
Vol 3 (4) ◽  
pp. 45
Author(s):  
Eleonore Fröhlich
Keyword(s):  
Animal Models ◽  
In Silico ◽  
Particle Deposition ◽  
Drug Testing ◽  
Animal Studies ◽  
Inhalation Exposure ◽  
Animal Testing ◽  
The Future

Animal testing is mandatory in drug testing and is the gold standard for toxicity and efficacy evaluations. This situation is expected to change in the future as the 3Rs principle, which stands for the replacement, reduction, and refinement of the use of animals in science, is reinforced by many countries. On the other hand, technologies for alternatives to animal testing have increased. The need to develop and use alternatives depends on the complexity of the research topic and also on the extent to which the currently used animal models can mimic human physiology and/or exposure. The lung morphology and physiology of commonly used animal species differs from that of human lungs, and the realistic inhalation exposure of animals is challenging. In vitro and in silico methods can assess important aspects of the in vivo effects, namely particle deposition, dissolution, action at, and permeation through, the respiratory barrier, and pharmacokinetics. This review discusses the limitations of animal models and exposure systems and proposes in vitro and in silico techniques that could, when used together, reduce or even replace animal testing in inhalation testing in the future.

scholarly journals Dolutegravir impairs stem cell-based 3D morphogenesis models in a manner dependent on dose and timing of exposure: an implication for its developmental toxicity

2021 ◽  
Author(s):  
Lauren Kirkwood-Johnson ◽  
Nana Katayama ◽  
Yusuke Marikawa
Keyword(s):  
Stem Cells ◽  
Animal Studies ◽  
Expression Profiles ◽  
Developmental Toxicity ◽  
Strand Transfer ◽  
In Vitro Morphogenesis ◽  
Transfer Inhibitor ◽  
Timing Of Exposure ◽  
Integrase Strand Transfer Inhibitor

Abstract Dolutegravir is an anti-retroviral drug of the integrase strand transfer inhibitor class used to treat HIV infection. It is the recommended first-line regimen for most people, including women of childbearing age. However, some human and animal studies have suggested that dolutegravir causes birth defects, although its developmental toxicity remains controversial. Here, we investigated the adverse effects of dolutegravir using pluripotent stem cell-based in vitro morphogenesis models that have previously been validated as effective tools to assess the developmental toxicity of various chemicals. Dolutegravir diminished the growth and axial elongation of the morphogenesis model of mouse pluripotent stem cells at exposures of 2 μM and above in a concentration-dependent manner. Concomitantly, dolutegravir altered the expression profiles of developmental regulator genes involved in embryonic patterning. The adverse effects were observed when the morphogenesis model was exposed to dolutegravir at early stages of development, but not at later stages. The potency and molecular impact of dolutegravir on the morphogenesis model were distinct from other integrase strand transfer inhibitors. Lastly, dolutegravir altered the growth and gene expression profiles of the morphogenesis model of human embryonic stem cells at 1 μM and above. These studies demonstrate that dolutegravir impairs morphological and molecular aspects of the in vitro morphogenesis models in a manner dependent on dose and timing of exposure through mechanisms that are unrelated to its action as an integrase strand transfer inhibitor. This finding will be useful for interpreting the conflicting outcomes regarding the developmental toxicity of dolutegravir in human and animal studies.

scholarly journals Electrochemical Oxidation as a Tool for Generating Vitamin D Metabolites

Molecules ◽  
2019 ◽  
Vol 24 (13) ◽  
pp. 2369 ◽  
Author(s):  
Navarro Suarez ◽  
Thein ◽  
Kallinich ◽  
Rohn
Keyword(s):  
Vitamin D ◽  
Phase Ii ◽  
Animal Studies ◽  
Ph Value ◽  
Oxidation Products ◽  
In Vitro Test ◽  
Vitamin D Metabolites ◽  
Constant Potential

The electrochemical behavior of the vitamers cholecalciferol and ergocalciferol was investigated in order to determine whether it is possible to evaluate phase-I and phase-II metabolism of these steroids and yield metabolites that can serve as reference material. The vitamers were electrochemically-oxidized using an electrochemical system (ROXY™ EC system). The influence of pH value, solvent, and potential was evaluated. When using methanol or ethanol, the formation of artificial methoxy or ethoxy groups, respectively, was observed, while the use of acetonitrile did not show any formation of further functional groups. A neutral pH value and use of a constant potential led to the highest number of oxidation products with intensive signals. Additionally, a binding study between vitamin D and glucuronic acid as an example for phase-II conjugation was carried out. It was possible to detect adduct formation. Coupling mass spectrometry directly to electrochemistry (EC-MS) is a promising approach for generating vitamin D metabolites and/or yielding a number of metabolites without in vivo or in vitro test systems. It can support or even replace animal studies in the long-term and might be promising for yielding reference compounds.

Reproductive Toxicity Testing: Evaluating and Developing New Testing Systems

1985 ◽  
Vol 4 (2) ◽  
pp. 163-171 ◽  
Author(s):  
J. C. Lamb
Keyword(s):  
Environmental Protection Agency ◽  
Food Additives ◽  
Reproductive Toxicity ◽  
Toxicity Testing ◽  
Reproductive Function ◽  
Test System ◽  
Toxic Substances ◽  
Animal Testing ◽  
In Vitro Techniques

Reproductive toxicity testing systems are used by national and international regulatory agencies. Protocols have not been standardized between agencies or even within certain agencies. Although there have been efforts at standardization, a certain amount of the differences between testing protocols is a reflection of the needs of the particular agency. New developments in in vitro techniques might lead to new test systems, but reproductive function is dependent upon the interaction of various cells and organs that cannot presently be copied in the test tube; this makes whole-animal testing systems a necessity. The present whole-animal models used by the Food and Drug Administration include the 3 segment reproduction studies used for testing drug safety and the multigeneration studies used for food additives. The Environmental Protection Agency has adopted 2 similar versions of a 2-generation study for the Office of Pesticide Programs and the Office of Toxic Substances. The National Toxicology Program, although not a regulatory agency, has taken a prominent role in reproductive toxicity testing, test system development, and test system evaluation. A new testing system, Fertility Assessment by Continuous Breeding (FACB), is currently being studied as a cost-effective and reliable alternative test system. The FACB protocol houses male and female mice as breeding pairs and removes offspring as soon as they are born during the first 14 weeks to allow continuous mating. Each breeding pair normally has up to 5 litters, and the last litter is saved to evaluate the second generation. The efficiency, reliability, and expense of the protocol are being compared to the existing testing systems.

Integrated Decision-tree Testing Strategies for Developmental and Reproductive Toxicity with Respect to the Requirements of the EU REACH Legislation

2008 ◽  
Vol 36 (1) ◽  
pp. 65-80 ◽  
Author(s):  
Christina Grindon ◽  
Robert Combes ◽  
Mark T.D. Cronin ◽  
David W. Roberts ◽  
John F. Garrod
Keyword(s):  
Risk Assessment ◽  
Decision Tree ◽  
Endocrine Disruption ◽  
Reproductive Toxicity ◽  
Toxicity Testing ◽  
Alternative Methods ◽  
The European Union ◽  
Animal Testing ◽  
Testing Strategies

Liverpool John Moores University and FRAME conducted a research project, sponsored by Defra, on the status of alternatives to animal testing with regard to the European Union REACH (Registration, Evaluation and Authorisation of Chemicals) system for the safety testing and risk assessment of chemicals. The project covered all the main toxicity endpoints associated with the REACH system. This paper focuses on the prospects for the use of alternative methods (both in vitro and in silico) in developmental and reproductive toxicity testing. It considers many tests based on primary cells and cell lines, and the available expert systems and QSARs for developmental and reproductive toxicity, and also covers tests for endocrine disruption. Ways in which reduction and refinement measures can be used are also discussed, particularly the use of an enhanced one-generation reproductive study, which could potentially replace the two-generation study, and therefore considerably reduce the number of animals required in reproductive toxicity. Decision-tree style integrated testing strategies are also proposed for developmental and reproductive toxicity and for endocrine disruption, followed by a number of recommendations for the future facilitation of developmental and reproductive toxicity testing, with respect to human risk assessment.

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