scholarly journals Prediction of dose-dependent in vivo acetylcholinesterase inhibition by profenofos in rats and humans using physiologically based kinetic (PBK) modeling-facilitated reverse dosimetry

2021 ◽  
Vol 95 (4) ◽  
pp. 1287-1301
Author(s):  
Isaac Omwenga ◽  
Shensheng Zhao ◽  
Laetitia Kanja ◽  
Hans Mol ◽  
Ivonne M. C. M. Rietjens ◽  
...  

AbstractOrganophosphate pesticides (OPs) are known to inhibit acetylcholine esterase (AChE), a critical effect used to establish health-based guidance values. This study developed a combined in vitro–in silico approach to predict AChE inhibition by the OP profenofos in rats and humans. A physiologically based kinetic (PBK) model was developed for both species. Parameter values for profenofos conversion to 4-bromo-2-chlorophenol (BCP) were derived from in vitro incubations with liver microsomes, liver cytosol, and plasma from rats (catalytic efficiencies of 1.1, 2.8, and 0.19 ml/min/mg protein, respectively) and humans (catalytic efficiencies of 0.17, 0.79, and 0.063 ml/min/mg protein, respectively), whereas other chemical-related parameter values were derived using in silico calculations. The rat PBK model was evaluated against literature data on urinary excretion of conjugated BCP. Concentration-dependent inhibition of rat and human AChE was determined in vitro and these data were translated with the PBK models to predicted dose-dependent AChE inhibition in rats and humans in vivo. Comparing predicted dose-dependent AChE inhibition in rats to literature data on profenofos-induced AChE inhibition revealed an accurate prediction of in vivo effect levels. Comparison of rat predictions (BMDL10 of predicted dose–response data of 0.45 mg/kg bw) and human predictions (BMDL10 of predicted dose–response data of 0.01 mg/kg bw) suggests that humans are more sensitive than rats, being mainly due to differences in kinetics. Altogether, the results demonstrate that in vivo AChE inhibition upon acute exposure to profenofos was closely predicted in rats, indicating the potential of this novel approach method in chemical hazard assessment.

2019 ◽  
Author(s):  
Mengying Zhang ◽  
Bennard van Ravenzwaay ◽  
Ivonne M C M Rietjens

Abstract The present study assessed the potential of a generic physiologically based kinetic (PBK) model to convert in vitro data for estrogenicity to predict the in vivo uterotrophic response in rats for diethylstibestrol (DES), ethinylestradiol (EE2), genistein (GEN), coumestrol (COU), and methoxychlor (MXC). PBK models were developed using a generic approach and in vitro concentration-response data from the MCF-7 proliferation assay and the yeast estrogen screening assay were translated into in vivo dose-response data. Benchmark dose analysis was performed on the predicted data and available in vivo uterotrophic data to evaluate the model predictions. The results reveal that the developed generic PBK model adequate defines the in vivo kinetics of the estrogens. The predicted dose-response data of DES, EE2, GEN, COU, and MXC matched the reported in vivo uterus weight response in a qualitative way, whereas the quantitative comparison was somewhat hampered by the variability in both in vitro and in vivo data. From a safety perspective, the predictions based on the MCF-7 proliferation assay would best guarantee a safe point of departure for further risk assessment although it may be conservative. The current study indicates the feasibility of using a combination of in vitro toxicity data and a generic PBK model to predict the relative in vivo uterotrophic response for estrogenic chemicals.


Author(s):  
Danlei Wang ◽  
Maartje H. Rietdijk ◽  
Lenny Kamelia ◽  
Peter J. Boogaard ◽  
Ivonne M. C. M. Rietjens

AbstractDevelopmental toxicity testing is an animal-intensive endpoints in toxicity testing and calls for animal-free alternatives. Previous studies showed the applicability of an in vitro–in silico approach for predicting developmental toxicity of a range of compounds, based on data from the mouse embryonic stem cell test (EST) combined with physiologically based kinetic (PBK) modelling facilitated reverse dosimetry. In the current study, the use of this approach for predicting developmental toxicity of polycyclic aromatic hydrocarbons (PAHs) was evaluated, using benzo[a]pyrene (BaP) as a model compound. A rat PBK model of BaP was developed to simulate the kinetics of its main metabolite 3-hydroxybenzo[a]pyrene (3-OHBaP), shown previously to be responsible for the developmental toxicity of BaP. Comparison to in vivo kinetic data showed that the model adequately predicted BaP and 3-OHBaP blood concentrations in the rat. Using this PBK model and reverse dosimetry, a concentration–response curve for 3-OHBaP obtained in the EST was translated into an in vivo dose–response curve for developmental toxicity of BaP in rats upon single or repeated dose exposure. The predicted half maximal effect doses (ED50) amounted to 67 and 45 mg/kg bw being comparable to the ED50 derived from the in vivo dose–response data reported for BaP in the literature, of 29 mg/kg bw. The present study provides a proof of principle of applying this in vitro–in silico approach for evaluating developmental toxicity of BaP and may provide a promising strategy for predicting the developmental toxicity of related PAHs, without the need for extensive animal testing.


Author(s):  
Shensheng Zhao ◽  
Sebastiaan Wesseling ◽  
Bert Spenkelink ◽  
Ivonne M. C. M. Rietjens

AbstractThe present study predicts in vivo human and rat red blood cell (RBC) acetylcholinesterase (AChE) inhibition upon diazinon (DZN) exposure using physiological based kinetic (PBK) modelling-facilitated reverse dosimetry. Due to the fact that both DZN and its oxon metabolite diazoxon (DZO) can inhibit AChE, a toxic equivalency factor (TEF) was included in the PBK model to combine the effect of DZN and DZO when predicting in vivo AChE inhibition. The PBK models were defined based on kinetic constants derived from in vitro incubations with liver fractions or plasma of rat and human, and were used to translate in vitro concentration–response curves for AChE inhibition obtained in the current study to predicted in vivo dose–response curves. The predicted dose–response curves for rat matched available in vivo data on AChE inhibition, and the benchmark dose lower confidence limits for 10% inhibition (BMDL10 values) were in line with the reported BMDL10 values. Humans were predicted to be 6-fold more sensitive than rats in terms of AChE inhibition, mainly because of inter-species differences in toxicokinetics. It is concluded that the TEF-coded DZN PBK model combined with quantitative in vitro to in vivo extrapolation (QIVIVE) provides an adequate approach to predict RBC AChE inhibition upon acute oral DZN exposure, and can provide an alternative testing strategy for derivation of a point of departure (POD) in risk assessment.


1978 ◽  
Vol 56 (5) ◽  
pp. 823-827 ◽  
Author(s):  
C. J. Hanna ◽  
S. H. Roth

The guinea pig tracheal spiral strip is a useful preparation for studying bronchoconstrictor and bronchodilator compounds. Employing a simple and rapid modification of this technique, experiments were performed in vitro to quantitate the effects of selected bronchospastic agents on guinea pig tracheobronchial smooth muscle. Three sections of the main airways were prepared from each animal: an upper tracheal, a lower tracheal, and a bronchial segment. The dose-dependent contractile responses of the three tissue segments were determined for carbachol, acetylcholine, histamine, 5-hydroxytryptamine, and bradykinin, Differences were observed amongst the agonists in magnitudes of contraction, effective concentration ranges, and slopes of dose–response curves. ED25, ED50, and ED75, values were calculated from regression analysis of dose–response data. The relative order for these agents to produce maximum contractions was found to be carbachol [Formula: see text] acetylcholine > histamine > 5-hydroxytryptamine > bradykinin. Furthermore, it was found that there was no significant difference between the three tissue segments in their responses to the various agonists.


1979 ◽  
Author(s):  
Chr. Nowotny ◽  
K. Lechner ◽  
H. Niessner ◽  
E. Thaler

FEIBA causes in vitro a concentration-dependent shortening of APTT of hemophilic plasma containing antibody to factor VIII. Since the potency of preparation is based on this in vitro test, it was of interest to examine whether a dose-dependent shortening of APTT and clotting time is also observed under in vivo conditions, APTT, whole blood glass clotting time and reaction time (=R value of thrombelastogramm) were determined before and 30 to 60 min. after 91 infusions of FE IBA (dose range 6 - 100 U/kg) to 10 hemophiliacs with antibody. Although there was a considerable scatter, a significant inverse correlation between the dose of FE IBA and postinfusion APTT and R-value was observedThe dose response curve was, however, rather flat. No significant correlation existed between FE IBA dose and glass clotting time. The effect of FE IBA on the APTT was not dependent on the antibody level, both, in vitro and in vivo. There was only a slight variant ot the effect among different patients, but a marked variation among different lots ot tne preparation, FE IBA seems to have a weak clinical hemostatic effect. A clear relationship between dose and clinical effect could not be established but it appears that doses higher than 50 U/kg are not more effective than smaller doses.


Biomedicines ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 68 ◽  
Author(s):  
Md. Adnan ◽  
Md. Nazim Uddin Chy ◽  
A.T.M. Mostafa Kamal ◽  
Md Obyedul Kalam Azad ◽  
Kazi Asfak Ahmed Chowdhury ◽  
...  

Piper sylvaticum Roxb. is traditionally used by the indigenous people of tropical and subtropical countries like Bangladesh, India, and China for relieving the common cold or a variety of chronic diseases, such as asthma, chronic coughing, piles, rheumatic pain, headaches, wounds, tuberculosis, indigestion, and dyspepsia. This study tested anxiolytic and antioxidant activities by in vivo, in vitro, and in silico experiments for the metabolites extracted (methanol) from the leaves and stems of P. sylvaticum (MEPSL and MEPSS). During the anxiolytic evaluation analyzed by elevated plus maze and hole board tests, MEPSL and MEPSS (200 and 400 mg/kg, body weight) exhibited a significant and dose-dependent reduction of anxiety-like behavior in mice. Similarly, mice treated with MEPSL and MEPSS demonstrated dose-dependent increases in locomotion and CNS simulative effects in open field test. In addition, both extracts (MEPSL and MEPSS) also showed moderate antioxidant activities in DPPH scavenging and ferric reducing power assays compared to the standard, ascorbic acid. In parallel, previously isolated bioactive compounds from this plant were documented and subjected to a molecular docking study to correlate them with the pharmacological outcomes. The selected four major phytocompounds displayed favorable binding affinities to potassium channel and xanthine oxidoreductase enzyme targets in molecular docking experiments. Overall, P. sylvaticum is bioactive, as is evident through experimental and computational analysis. Further experiments are necessary to evaluate purified novel compounds for the clinical evaluation.


2021 ◽  
Vol 4 (s1) ◽  
Author(s):  
Ermes Botte ◽  
Pietro Vagaggini ◽  
Joana Costa ◽  
Lara Faccani ◽  
Ilaria Zanoni ◽  
...  

Dose assessment is essential for understanding the mechanisms triggering nanomaterial toxicity in vitro and for meaningful translations to in vivo. We propose a novel computational approach for improving the accuracy of biological dose-response characterization, demonstrating its robustness for insoluble Engineered Nanomaterials (ENMs).


2010 ◽  
Vol 118 (2) ◽  
pp. 470-484 ◽  
Author(s):  
Jochem Louisse ◽  
Esther de Jong ◽  
Johannes J. M. van de Sandt ◽  
Bas J. Blaauboer ◽  
Ruud A. Woutersen ◽  
...  

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