Organisation For Economic Co-operation And Development Guidelines Research Articles

Towards Standardization for Determining Dissolution Kinetics of Nanomaterials in Natural Aquatic Environments: Continuous Flow Dissolution of Ag Nanoparticles.

The dissolution of metal-based engineered nanomaterials (ENMs) in aquatic environments is an important mechanism governing the release of toxic dissolved metals. For the registration of ENMs at regulatory bodies such as REACH, their dissolution behavior must therefore be assessed using standardized experimental approaches. To date, there are no standardized procedures for dissolution testing of ENMs in environmentally relevant aquatic media, and the Organisation for Economic Co-operation and Development (OECD) strongly encourages their development into test guidelines. According to a survey of surface water hydrochemistry, we propose to use media with low concentrations of Ca2+ and Mg2+ for a better simulation of the ionic background of surface waters, at pH values representing acidic (5 < pH < 6) and near-neutral/alkaline (7 < pH < 8) waters. We evaluated a continuous flow setup adapted to expose small amounts of ENMs to aqueous media, to mimic ENMs in surface waters. For this purpose, silver nanoparticles (Ag NPs) were used as model for soluble metal-bearing ENMs. Ag NPs were deposited onto a 10 kg.mol−1 membrane through the injection of 500 µL of a 5 mg.L−1 or 20 mg.L−1 Ag NP dispersion, in order to expose only a few micrograms of Ag NPs to the aqueous media. The dissolution rate of Ag NPs in 10 mM NaNO3 was more than two times higher for ~2 µg compared with ~8 µg of Ag NPs deposited onto the membrane, emphasizing the importance of evaluating the dissolution of ENMs at low concentrations in order to keep a realistic scenario. Dissolution rates of Ag NPs in artificial waters (2 mM Ca(NO3)2, 0.5 mM MgSO4, 0–5 mM NaHCO3) were also determined, proving the feasibility of the test using environmentally relevant media. In view of the current lack of harmonized methods, this work encourages the standardization of continuous flow dissolution methods toward OECD guidelines focused on natural aquatic environments, for systematic comparisons of nanomaterials and adapted risk assessments.

Convergence of corporate governance in state-owned enterprises: A case study in an emerging market using OECD Guidelines

This article investigates an under-researched area of government activity and corporate governance reform, namely, corporate governance in state-owned enterprises. State-owned enterprises (SOEs) form a significant part of the economy in many countries and particularly in Asia. This article contributes to the larger corporate governance convergence debate by investigating whether arrangements originally conceptualised in the private sector prior to going global have indeed gone global and extended into the public sector. The article approaches the problem by investigating three interrelated questions posed by Clarke (2011): whether convergence could occur, whether it is occurring and whether such convergence is a good thing. Using a combination of DiMaggio and Powell’s (1983) institutional framework, convergence theory and doctrinal methods, the article sets the Organisation for Economic Co-operation and Development (OECD) Guidelines on Corporate Governance of State-Owned Enterprises as a benchmark and assesses Philippine state-owned enterprise law and practices. The analysis revealed a high level of convergence. We find evidence that convergence was occurring by a series of high-level dialogues, that it was open and sufficiently non prescriptive to allow selective adoption and adaptation to local context. In evaluating the convergence, we believe that the benefit to the overall welfare of the Philippines outweighed the drawbacks

Integrated skin sensitization assessment based on OECD methods (I): Deriving a point of departure for risk assessment_suppl2

Three guidelines covering key events in the skin sensitization adverse outcome pathway are endorsed by the Organisation for Economic Co-operation and Development (OECD). A recent guideline covers defined approaches (DA) to combine data from these tests for regulatory (sub)classification. The guideline methods provide continuous data that could characterize the sensitization potency on a more granular scale beyond (sub)classifications. We assembled a comprehensive database of in vitro and in vivo results from OECD guideline tests. Building on a previous approach using regression models, we provide quantitative models using input data from the kinetic direct peptide reactivity assay (kDPRA), the KeratinoSens™ (KS) assay, and the human cell line activation test (h-CLAT) to calculate a point of departure (PoD) in the form of a predicted local lymph node assay (LLNA) EC3 value for use in risk assessment. Predictive models include results from either two or all three assays. Detailed analysis versus in vivo data estimates redundancy between different tests and helps guide model selection. All models were tested on a set of case studies selected for their availability of multiple LLNA reference data in the OECD database. The predicted PoDs were within or close to the range of the variation of the historical LLNA data for most of these cases studies, and overall, the models predicted the in vivo value with a median fold-misprediction factor of around 2.5. The robustness of the models was characterized by comparing a comprehensive historical database versus the curated dataset provided by the OECD working group on DA.

Integrated skin sensitization assessment based on OECD methods (I): Deriving a point of departure for risk assessment_suppl4

Three guidelines covering key events in the skin sensitization adverse outcome pathway are endorsed by the Organisation for Economic Co-operation and Development (OECD). A recent guideline covers defined approaches (DA) to combine data from these tests for regulatory (sub)classification. The guideline methods provide continuous data that could characterize the sensitization potency on a more granular scale beyond (sub)classifications. We assembled a comprehensive database of in vitro and in vivo results from OECD guideline tests. Building on a previous approach using regression models, we provide quantitative models using input data from the kinetic direct peptide reactivity assay (kDPRA), the KeratinoSens™ (KS) assay, and the human cell line activation test (h-CLAT) to calculate a point of departure (PoD) in the form of a predicted local lymph node assay (LLNA) EC3 value for use in risk assessment. Predictive models include results from either two or all three assays. Detailed analysis versus in vivo data estimates redundancy between different tests and helps guide model selection. All models were tested on a set of case studies selected for their availability of multiple LLNA reference data in the OECD database. The predicted PoDs were within or close to the range of the variation of the historical LLNA data for most of these cases studies, and overall, the models predicted the in vivo value with a median fold-misprediction factor of around 2.5. The robustness of the models was characterized by comparing a comprehensive historical database versus the curated dataset provided by the OECD working group on DA.

Integrated skin sensitization assessment based on OECD methods (I): Deriving a point of departure for risk assessment.

Three guidelines covering key events in the skin sensitization adverse outcome pathway are endorsed by the Organisation for Economic Co-operation and Development (OECD). A recent guideline covers defined approaches (DA) to combine data from these tests for regulatory (sub)classification. The guideline methods provide continuous data that could charac-terize the sensitization potency on a more granular scale beyond (sub)classifications. We assembled a comprehensive database of in vitro and in vivo results from OECD guideline tests. Building on a previous approach using regression models, we provide quantitative models using input data from the kinetic direct peptide reactivity assay (kDPRA), the KeratinoSens™ (KS) assay, and the human cell line activation test (h-CLAT) to calculate a point of departure (PoD) in the form of a predicted local lymph node assay (LLNA) EC3 value for use in risk assessment. Predictive models include results from either two or all three assays. Detailed analysis versus in vivo data estimates redundancy between different tests and helps guide model selection. All models were tested on a set of case studies selected for their availability of multiple LLNA reference data in the OECD database. The predicted PoDs were within or close to the range of the variation of the historical LLNA data for most of these cases studies, and overall, the models predicted the in vivo value with a median fold-misprediction factor of around 2.5. The robustness of the models was characterized by comparing a comprehensive historical database versus the curated dataset provided by the OECD working group on DA.

Integrated skin sensitization assessment based on OECD methods (I): Deriving a point of departure for risk assessment_suppl1

Three guidelines covering key events in the skin sensitization adverse outcome pathway are endorsed by the Organisation for Economic Co-operation and Development (OECD). A recent guideline covers defined approaches (DA) to combine data from these tests for regulatory (sub)classification. The guideline methods provide continuous data that could characterize the sensitization potency on a more granular scale beyond (sub)classifications. We assembled a comprehensive database of in vitro and in vivo results from OECD guideline tests. Building on a previous approach using regression models, we provide quantitative models using input data from the kinetic direct peptide reactivity assay (kDPRA), the KeratinoSens™ (KS) assay, and the human cell line activation test (h-CLAT) to calculate a point of departure (PoD) in the form of a predicted local lymph node assay (LLNA) EC3 value for use in risk assessment. Predictive models include results from either two or all three assays. Detailed analysis versus in vivo data estimates redundancy between different tests and helps guide model selection. All models were tested on a set of case studies selected for their availability of multiple LLNA reference data in the OECD database. The predicted PoDs were within or close to the range of the variation of the historical LLNA data for most of these cases studies, and overall, the models predicted the in vivo value with a median fold-misprediction factor of around 2.5. The robustness of the models was characterized by comparing a comprehensive historical database versus the curated dataset provided by the OECD working group on DA.

Integrated skin sensitization assessment based on OECD methods (I): Deriving a point of departure for risk assessment_suppl3

Three guidelines covering key events in the skin sensitization adverse outcome pathway are endorsed by the Organisation for Economic Co-operation and Development (OECD). A recent guideline covers defined approaches (DA) to combine data from these tests for regulatory (sub)classification. The guideline methods provide continuous data that could characterize the sensitization potency on a more granular scale beyond (sub)classifications. We assembled a comprehensive database of in vitro and in vivo results from OECD guideline tests. Building on a previous approach using regression models, we provide quantitative models using input data from the kinetic direct peptide reactivity assay (kDPRA), the KeratinoSens™ (KS) assay, and the human cell line activation test (h-CLAT) to calculate a point of departure (PoD) in the form of a predicted local lymph node assay (LLNA) EC3 value for use in risk assessment. Predictive models include results from either two or all three assays. Detailed analysis versus in vivo data estimates redundancy between different tests and helps guide model selection. All models were tested on a set of case studies selected for their availability of multiple LLNA reference data in the OECD database. The predicted PoDs were within or close to the range of the variation of the historical LLNA data for most of these cases studies, and overall, the models predicted the in vivo value with a median fold-misprediction factor of around 2.5. The robustness of the models was characterized by comparing a comprehensive historical database versus the curated dataset provided by the OECD working group on DA.

Assessment of the acute and sub-acute toxicity of the ethanolic extract of the aerial parts of Crassocephalum rabens (Asteraceae) in rats

This pioneering study was to assess the acute and sub-acute toxicity of the ethanolic extract of the aerial parts of Crassocephalum rabens (Asteraceae) in rats. C. rabens is a common vegetable and herb for treating inflammation-related syndromes in Taiwan. Pharmacological studies have unveiled that the extracts of C. rabens have potential to become hepatoprotective, anti-inflammatory, or anti-cancer agents. The toxicological effects of the aerial parts of C. rabens in rodents are still elusive. For the acute toxicity study, rats were administrated with a single dose of 5,000 mg/kg body weight (BW) and observed for 14 days in accordance with the Organization for Economic Cooperation and Development (OECD) guideline No. 420. For the sub-acute toxicity study, animals were orally treated with daily doses of 0, 416.7, 833.3, and 1,666.7 mg/kg BW for 28 days based on the OECD guideline No. 407. The toxicity of the repeated dose was observed with anthropometric, hematological, and biochemical parameters as well as histology. The mortality and critical pathological and biochemical abnormalities were not observed in the acute and/or sub-acute toxicity studies. The oral median lethal dose (LD50) of the extract was greater than 5000 mg/kg BW. The no-observed-adverse-effect-level (NOAEL) in male and female rats was greater than 1,666.7 mg/kg BW. As such, the extract of the aerial parts of C. rabens is considered a non-toxic substance.

An overview of current alternative models in the context of ocular surface toxicity.

The 21st century has seen a steadily increasing social awareness of animal suffering, with increased attention to ethical considerations. Developing new integrated approaches to testing and assessment (IATA) strategies is an Organisation for Economic Co-operation and Development (OECD) goal to reduce animal testing. Currently, there is a lack of alternative models to test for ocular surface toxicity (aside from irritation) in lieu of the Draize eye irritation test (OECD guideline No. 405) performed in rabbits. Five alternative in vitro or ex vivo methods have been validated to replace this reference test, but only in combination. However, pathologies like Toxicity-Induced Dry Eye (TIDE), cataract, glaucoma, and neuropathic pain can occur after exposure to a pharmaceutical product or chemical and therefore need to be anticipated. To do so, new models of lacrimal glands, lens, and neurons innervating epithelia are required. These models must take into account real-life exposure (dose, time, and tear film clearance). The scientific community is working hard to develop new, robust, alternative, in silico, and in vitro models, while attempting to balance ethics and availability of biological materials. This review provides a broad overview of the validated methods for analyzing ocular irritation and those still used by some industries, as well as promising models that need to be optimized according to the OECD. Finally, we give an overview of recently developed innovative models, which could become new tools in the evaluation of ocular surface toxicity within the scope of IATAs.

Acute and Repeated Dose Toxicity Study of Clevira Syrup – A Polyherbal Formulation

Aim and Objectives: This study evaluated the acute and repeated dose toxicity effects of Clevira Syrup Polyherbal formulation (CSPHF), which was prepared from ten different herbs, well known and widely used in traditional medicine for the management of viral infections and other inflammatory disease conditions. Individually these herbs (Carica papaya, Melia azedarach, Andrographis paniculata, Vetiveria zizanioides, Trichosanthes dioica, Cyperus rotundus, Zingiber officinale, Piper nigrum, Mollugo Cerviana and Tinospora cordifolia )were completely safe, but the polyherbal formulation effects were not known. Thus, this study was done for the investigation of toxicological profile of CSPHF in Wistar Albino rats. Methods: As per OECD(Organisation for Economic Co-operation and Development) guidelines 423 and 407, Acute and Repeated dose toxicity study were proceeded. In the acute toxicity study a single dose of CSPHF (2000mg/kg) was administered orally to female Wistar rats and in repeated dose toxicity study, CSPHF was administered orally in Control group and three different doses (1000, 500 and 250mg/kg body weight) to both male and female wistar albino rats for 28 days. At the end of the study, the animals were euthanized, observed the external and internal morphology (Acute Toxicity) and assessed the effect of CSPHF on histopathological and biochemical parameters (Repeated Dose toxicity study). Results: In acute toxicity study, there were no visual signs of toxicity of CSPHF (2000mg/kg) observed, whereas in Repeated dose toxicity study Ischaemia, inflammation and hematoma of the internal organs were observed at 1000mg/kg dose, but no such toxic features were seen at 500 and 250mg/kg dose of CSPHF. Conclusion: The results of the Acute and Repeated Dose toxicity study could be authenticated in future studies, which will be more useful and evidence based for the management of Viral infectionsduring pandemics.

Acute toxicity of aqueous extract of Ambrosia arborescens Mill. on biochemical and histopathological parameters in rats.

Medicinal plants play an important role in the management of various diseases, so their use has become widespread. However, in some cases the population uses plant species regardless of the toxicity they may possess. The objective of this study was to evaluate the acute toxicity of aqueous extract from the leaves of Ambrosia arborescens Mill. on the biochemical and histopathological parameters of albino Holtzman rats. To do this, the leaves of A. arborescens were collected in the province of Julcan, La Libertad Region-Peru. OECD (Organisation for Economic Cooperation and Development) guideline 423 was conducted, forming experimental groups of 10 animals each one (5 males and 5 females): Group I (Control), which received 2mL physiological saline solution (SSF 0.9%), Groups II and III (A. arborescens-300 and A. arborescens-2000), which were given the aqueous extract leaves of A. arborescens in a single dose of 300 and 2000mg/kg/day, respectively. On the 14th day of exposure, biochemical (creatinine, ALT and AST) and histopathological parameters were measured. The results show that the aqueous extract of A. arborescens at the dose of 2000mg/kg produces an increase in biochemical parameters which is related to histopathological analysis of liver and renal tissue with mild congestion. The study concludes that the aqueous extract leaves of A. arborescens has a LD50 greater than 2000mg/kg and produces mild congestion in kidneys and liver, but showed no significant toxicological changes in the other albino Holtzman rats organs.

Evaluation of Acute Toxicity of Some Medicinal Plants and their Combination in Albino Mice

Medicinal plants find use across different cultures in the world. People have derived numerous benefits by using various plants for centuries. Herbal drugs are supposed to be safe, but there are chances these might cause toxicity and other complications. Thus toxicity studies are essential for a medicinal plant before being used in humans. The present research revolves around studying the acute toxicity of Ocimum kilimandscharicum, Thymus serpyllum, Spilanthes acmella and their combination in equal ratio (COMB). For preparing the combination of extracts, the ethanolic extracts of the three plants were combined in equal amounts and administered to the animals. The acute toxicity study was carried out according to OECD (The Organisation for Economic Co-operation and Development) guideline 423 for acute toxicity. The animals were divided into four groups each containing three animals each. These groups were respectively administered ethanolic extract of O. kilimandscharicum, T. serpyllum, S. acmella and COMB in a dose of 2000 mg/kg. The animals were observed for signs of toxicity and mortality at durations specified by OECD. The results demonstrated that extracts of the three medicinal plants used in the study and their combination were found to be safe up to 2000 mg/kg.

Genotoxicity Evaluation of Propyl-Propane-Thiosulfinate (PTS) from Allium genus Essential Oils by a Combination of Micronucleus and Comet Assays in Rats.

Propyl-propanethiosulfinate (PTS) is a component of Allium essential oils. This organosulfur molecule can be used as a feed additive to decrease the appearance of bacterial resistances caused by the residues of antibiotics. In previous in vitro genotoxicity studies, contradictory results were reported for PTS. In this work, the in vivo genotoxicity of PTS in male and female rats was assessed for the first time, following OECD (Organisation for Economic Co-operation and Development) guidelines. After oral administration (doses: 5.5, 17.4, and 55.0 mg/kg PTS body weight), a combination of the micronucleus (MN) assay (OECD 474) in bone marrow and the standard and enzyme-modified comet assay (OECD 489) was performed. After necropsy, histopathological studies were also carried out. The results did not show the in vivo genotoxicity of PTS at any doses assayed, revealed by the absence of increased MN, and DNA strand breaks or oxidative DNA damage in the standard and enzyme-modified comet assays. The histopathological study revealed that only the highest dose tested (55.0 mg/kg) in the liver and all dose groups in the stomach presented minimal pathological lesions in the organs studied. Consequently, the present work confirms that PTS is not genotoxic at the doses assayed, and it is a promising natural alternative to synthetic preservatives and antibiotics in animal feed.

ASPECTOS DA GOVERNANÇA DIGITAL DA ADMINISTRAÇÃO PÚBLICA FEDERAL DO BRASIL SOB A LUZ DAS ORIENTAÇÕES DA OCDE

The objective of this work is to analyze the digital governance of the federal public administration of Brazil, in the light of the global alignment on the theme. Having as object of study the formulations of the Organisation for Economic Co-Operation and Development (OECD), the Brazilian Digital Governance Strategy, and PDTIC 2017-2019, both from the Ministry of Planning. It is concluded that the analyzed actions, initiatives and policies, as well as the technical/theoretical formulations, prove that the Brazilian federal government is closely aligned to the OECD guidelines and directives on digital governance.

Acute Toxicity Study of the Combination of Azadirachta indica A. Juss. and Gynura procumbens (Lour.) Merr. Leave Extracts

Azadirachta indica A.Juss. and Gynura procumbens (Merr.) are medicinal herbs widely used in traditional medicine. Recent research on the combination of these two plants showed aggressive antioxidant activity. The combination results can improve insulin and beta-cell morphology and can increase insulin expression. The variety of activities performed is the basis for conducting acute toxicity tests on the ethanol extract of Azadirachta Indica A. Juss. and Gynura procumbens (Lour.) Merr. to increase public confidence in its efficacy and ensure the safety of its use. The acute toxicity test on the ethanol extract of Azadirachta Indica A. Juss. and Gynura procumbens (Lour.) Merr. was carried out on female Wistar rats by following the 423 procedures of OECD (Organization for Economic Cooperation and Development) Guideline with five groups of experimental animals, namely normal treatment, aquadest solvent treatment and 0.5 Na-CMC 0.5%, a separate treatment of the ethanol extract of Azadirachta Indica A. Juss., a separate treatment of the ethanol extract of Gynura procumbens (Lour.) Merr., and combination treatment of the ethanol extract of Azadirachta Indica A. Juss. and leaves of Gynura procumbens (Lour.) Merr. Furthermore, it was proceeded by observing the liver of the experimental animals histopathologically. The acute toxicity test results utilizing the 423 procedures of the OECD did not confirm any death or signs of toxicity in the experimental animals, and histopathological observations did not show any major histopathological damage. Based on these results, according to Globally Harmonized Classification System (GHS), the combination of the ethanol extract of Azadirachta Indica A. Juss. and Gynura procumbens (Lour.) Merr. is included in the unclassified category ( 2,000 mg/kg BW.

Micronucleus Formation in Primary Oropharyngeal Epithelial Cells Reveals Mutagenicity of Cement Dusts.

Epidemiological studies showed an increased risk of developing laryngeal head and neck squamous cell carcinoma (HNSCC) for employees working in the construction business. This suggested a causal link between exposure to cement particles and development of HNSCC but data were missing. We established an Organisation for Economic Co-operation and Development (OECD) guideline 487-conform micronucleus assay (MNA) using oropharyngeal mucosa-derived primary epithelial cells (OPCs) ex vivo. OPCs from healthy mucosa of 52 donors were cultured in vitro and incubated with serial concentrations of two common cement particles. Mitomycin C was used as a soluble positive control, and TiO2 and DQ12 were used as negative and positive particle controls. Bi-nucleated cells were counted and the mitotic index (MI) was determined. Subsequently, micronuclei-containing bi-nucleated cells (MN+) were counted. Cement particles, in concentrations not significantly reducing ex vivo proliferation according to mitotic index, dose-dependently increased micronuclei formation. Through the establishment of an OECD guideline 487 conform MNA, we demonstrate the mutagenic effects of cement on human OPCs.

Comparison of the in vitro assays to investigate the hepatic metabolism of seven pesticides in Cyprinus carpio and Oncorhynchus mykiss

Liver S9 fractions from common carp (Cyprinus carpio) and rainbow trout (Oncorhynchus mykiss) were incubated with seven pesticides (fenamidone, fenoxaprop-p-ethyl, penflufen, spirotetramat, tebuconazole, tembotrione and trifloxystrobin) and the metabolic pathways of the applied chemicals were determined by HPLC-high-resolution mass spectrometry.Five of the seven pesticides (fenamidone, penflufen, spirotetramat, trifloxystrobin and fenoxaprop-p-ethyl) revealed a higher metabolic capacity of rainbow trout liver fractions compared to carp liver fractions. The other two pesticides (tebuconazole and tembotrione) showed a similar and marginal biotransformation for liver S9 fractions of both species.Furthermore, four compounds (penflufen, spirotetramat, tembotrione and tebuconazole) were incubated with cryo-preserved hepatocytes of rainbow trout showing additional conjugated metabolites compared to liver S9 fractions. The incubations were performed with concentrations of 1 and 10 μM for experiments with liver S9 fractions and 5 μM with hepatocytes for up to 120 (liver S9 fractions) or 240 min (hepatocytes). A set of positive controls was used to confirm the metabolic capability of the in vitro systems.The comparison of the in vitro results from hepatocyte assays of penflufen and tebuconazole with the data from corresponding in vivo studies performed according to OECD (Organisation for Economic Co-operation and Development) guideline 305 exhibited a similar metabolic behavior for these pesticides and emphasizes the reliability of the in vitro assays.Besides investigation of the metabolism of plant protection products for research purposes, inter-species comparison by in vitro assays and the use of PBTK modelling approaches will allow improved environmental and dietary risk assessments.

Toxicological evaluations of betulinic acid and ursolic acid; common constituents of Houttuynia cordata used as an anthelmintic by the Naga tribes in North-east India

BackgroundBetulinic acid (BA) and ursolic acid (UA) are two major phytoconstituents of Houttuynia cordata Thunb., (Saururaceae) which is used as an anthelmintic in the traditional medicine system of the Nagas in Nagaland, India. This study evaluates their toxic potentials using rodent models (Swiss albino mice and Wistar rats) according to the OECD (Organization for Economic Cooperation and Development) guidelines. Acute and 28-day sub-acute oral toxicity studies were conducted, and evaluations were made based on biochemical, hematological, and histopathological observations.ResultsAcute oral toxicity study revealed the oral LD50 of both the test compounds to be > 2000 mg/kg in mice. Sub-acute administration of BA at 10 mg/kg body weight (b.w.) revealed a significant increase in serum glutamic oxaloacetic transaminase (SGOT), alkaline phosphatase (ALP), urea concentrations and eosinophil and lymphocyte counts in rats. Animals administered with 10 mg/kg b.w. UA revealed elevated neutrophil count, SGOT, ALP, and urea concentrations, whereas white blood cells (WBC), lymphocyte, and platelet counts were found to be low. Histopathological examinations of body organs revealed alterations in the architecture of the liver, kidney, and spleen tissues. Notably, all these alterations were recoverable as evident in the satellite group, indicating a recovering pattern from the toxic effects caused by the oral administration of these phytocompounds.ConclusionAlthough UA and BA possess several therapeutic properties, their long-term usage can cause mild toxicity in their users. This study also paves way for evaluating the optimum effective and safe dose of these phytocompounds.

Synthesis of Peptide-Immobilized Magnetic Beads, and Peptide Reactivity Assay for Assessing Skin Sensitization Utilizing Chromophore

DPRA (direct peptide reactivity assay) and ADRA (amino acid derivative reactivity assay), which are based on the biological events of skin sensitization, were developed as alternatives to the controversial animal experiments. These assays are described in the OECD (Organization for Economic Co-operation and Development) guideline, Test No. 442C. Although these assays have been endorsed by the industries and internationally accepted as promising and effective tests for in vitro skin sensitization, they suffer from several drawbacks, such as incompatibility with hydrophobic chemicals and complicated sample processing. Here, we demonstrated a chromophore-based solid phase peptide reaction assay in vitro using peptides immobilized on magnetic beads (C-SPRA-MB). We successfully synthesized lysine (Lys) and cysteine (Cys) immobilized on magnetic microbeads. However, Cys immobilized magnetic microbeads showed gradual decomposition of the magnetic beads due to SH oxidation. Using Lys immobilized magnetic microbeads, we demonstrated the capacity of C-SPRA-MB to predict skin sensitization by measuring free amino groups of the Lys after reaction with test chemicals. First, the free amines on the microbeads were reacted with bromophenol blue (BB). Then, by treatment with a saturated solution of Lys, the bound BBs were released and quantified. C-SPRA-MB provides high-throughput and accurate assays for assessments of chemicals, including with low-potency as skin sensitizers and poor water solubility. C-SPRA-MB may be useful for effective prediction of their skin sensitization potential in the process of compound screening, especially in the case of misclassified by DPRA and ADRA. Thus, C-SPRA-MB can be applied to assessing the sensitization potential of medical, pharmaceutical, cosmetics, and industrial compounds.

ERGO: Breaking Down the Wall between Human Health and Environmental Testing of Endocrine Disrupters.

ERGO (EndocRine Guideline Optimization) is the acronym of a European Union-funded research and innovation action, that aims to break down the wall between mammalian and non-mammalian vertebrate regulatory testing of endocrine disruptors (EDs), by identifying, developing and aligning thyroid-related biomarkers and endpoints (B/E) for the linkage of effects between vertebrate classes. To achieve this, an adverse outcome pathway (AOP) network covering various modes of thyroid hormone disruption (THD) in multiple vertebrate classes will be developed. The AOP development will be based on existing and new data from in vitro and in vivo experiments with fish, amphibians and mammals, using a battery of different THDs. This will provide the scientifically plausible and evidence-based foundation for the selection of B/E and assays in lower vertebrates, predictive of human health outcomes. These assays will be prioritized for validation at OECD (Organization for Economic Cooperation and Development) level. ERGO will re-think ED testing strategies from in silico methods to in vivo testing and develop, optimize and validate existing in vivo and early life-stage OECD guidelines, as well as new in vitro protocols for THD. This strategy will reduce requirements for animal testing by preventing duplication of testing in mammals and non-mammalian vertebrates and increase the screening capacity to enable more chemicals to be tested for ED properties.