The Evaluation of Pesticide Ingredients and Formulations In Vitro and Correlations with In Vivo Data

1995 ◽  
Vol 23 (5) ◽  
pp. 667-675
Author(s):  
Richard H. Clothier ◽  
Joanne Morris ◽  
William T. Lankford
Keyword(s):  
Exposure Period ◽  
Cellular Protein ◽  
In Vitro Assay ◽  
In Vitro Tests ◽  
Technical Grade ◽  
Vitro Assay ◽  
Pesticide Formulations ◽  
High Concentrations

Pesticides are often insoluble directly in aqueous solvents, but can be dissolved/suspended in surfactant-uased formulations. Both surfactants and pesticides can induce irritation. Since a single in vitro assay has proved inadequate for evaluating the toxicity of a chemical and its ability to cause an irritant response, a combination of assays was employed to examine the potential toxicities of two pesticide formulations. The surfactant-based vehicles had toxicities that reflected their surfactant concentration. The formulation containing 5% permethrin required a more concentrated vehicle than was needed to dissolve 0.1% cypermethrin. In vitro, the ID50 dose (i.e. the dose which inhibited the increase in total cellular protein by 50%) was 576μg/ml for the permethrin formulation and 1080μg/ml for the cypermethrin formulation. This corresponded closely to the ID50 values for the vehicles alone (464μg/ml and 1230μg/ml, respectively). When tested at high concentrations on confluent cells over a 1-minute exposure period to mimic potential exposure of the eye, the more concentrated vehicle, Lanosol 50 ME, was 4–6 times more toxic than Siege II. Technical grade permethrin and cypermethrin had low toxicities in each of the in vitro tests employed. Taken together, these results reflected the in vivo profiles available.

scholarly journals DIGESTIBLE ENERGY IN FORAGE BYIN VIVOANDIN VITROASSAYS

1970 ◽  
Vol 50 (3) ◽  
pp. 557-562 ◽  
Author(s):  
J. E. TROELSEN
Keyword(s):  
Energy Analysis ◽  
Energy Content ◽  
In Vitro Assay ◽  
Pure Species ◽  
Vitro Assay ◽  
Digestible Energy ◽  
The Relationship ◽  
Cattle And Sheep

Forage of six pure species was harvested for hay at several maturity stages during four years. The digestible energy content of 102 different lots of hay was determined by feeding to four groups of sheep during the same period, and by in vitro digestions and energy analysis of the undigested residues. The relationship between digestible energy content assayed by the two methods was highly significant (r = 0.85) and did not differ between years and species. Exclusion from regression of the hays containing less than 2 or more than 3 digestible kcal/g revealed that the in vitro assay could reproduce the in vivo digestible energy value with a standard deviation of 0.31 in over 70% of the hays. This represented the maturity and quality range of forage commonly fed to cattle and sheep. The in vitro assay therefore appeared promising for commercial quality determinations.

Integration of in vitro neurotoxicity data with biokinetic modelling for the estimation of in vivo neurotoxicity

2007 ◽  
Vol 26 (4) ◽  
pp. 333-338 ◽  
Author(s):  
Anna Forsby ◽  
Bas Blaauboer
Keyword(s):  
Exposure Period ◽  
Cellular Protein ◽  
In Vitro Toxicity ◽  
Target Tissue ◽  
Receptor Function ◽  
Human Neuroblastoma ◽  
Protein Levels ◽  
Effective Doses

Risk assessment of neurotoxicity is mainly based on in vivo exposure, followed by tests on behaviour, physiology and pathology. In this study, an attempt to estimate lowest observed neurotoxic doses after single or repeated dose exposure was performed. Differentiated human neuroblastoma SH-SY5Y cells were exposed to acrylamide, lindane, parathion, paraoxon, phenytoin, diazepam or caffeine for 72 hours. The effects on protein synthesis and intracellular free Ca2+concentration were studied as physiological endpoints. Voltage operated Ca2 +channel function, acetylcholine receptor function and neurite degenerative effects were investigated as neurospecific endpoints for excitability, cholinergic signal transduction and axonopathy, respectively. The general cytotoxicity, determined as the total cellular protein levels after the 72 hours exposure period, was used for comparison to the specific endpoints and for estimation of acute lethality. The lowest concentration that induced 20% effect (EC 20) obtained for each compound, was used as a surrogate for the lowest neurotoxic level (LOEL) at the target site in vivo. The LOELs were integrated with data on adsorption, distribution, metabolism and excretion of the compounds in physiologically-based biokinetic (PBBK) models of the rat and the lowest observed effective doses (LOEDs) were estimated for the test compounds. A good correlation was observed between the estimated LOEDs and experimental LOEDs found in literature for rat for all test compounds, except for diazepam. However, when using in vitro data from the literature on diazepam's effect on gamma-amino butyric acid (GABA)A receptor function for the estimation of LOED, the correlation between the estimated and experimental LOEDs was improved from a 10 000-fold to a 10-fold difference. Our results indicate that it is possible to estimate LOEDs by integrating in vitro toxicity data as surrogates for lowest observed target tissue levels with PBBK models, provided that some knowledge about toxic mechanisms is known. Human & Experimental Toxicology (2007) 26, 333—338

scholarly journals Mutagenicity evaluation of Anastatica hierochuntica L. aqueous extract in vitro and in vivo

2017 ◽  
Vol 243 (4) ◽  
pp. 375-385 ◽  
Author(s):  
Siti Rosmani Md Zin ◽  
Zahurin Mohamed ◽  
Mohammed A Alshawsh ◽  
Won F Wong ◽  
Normadiah M Kassim
Keyword(s):  
Aqueous Extract ◽  
Positive Control ◽  
In Vitro Assay ◽  
In Vivo Study ◽  
Sufficient Evidence ◽  
Aqueous Extracts ◽  
Mutagenic Potential ◽  
Vitro Assay

Anastatica hierochuntica L. ( A. hierochuntica), a folk medicinal plant, was evaluated for mutagenic potential via in vitro and in vivo assays. The in vitro assay was conducted according to modified Ames test, while the in vivo study was performed according to Organisation for Economic Co-operation and Development guideline for mammalian erythrocyte micronucleus assay. Four groups ( n= 5 males and 5 females per group) Sprague Dawley rats were randomly chosen as the negative control, positive control (received a single intramuscular injection of cyclophosphamide 50 mg/kg), 1000 and, 2000 mg/kg A. hierochuntica aqueous extracts. All groups except the positive control were treated orally for three days. Findings of the in vitro assay showed mutagenic potential of AHAE at 0.04 and 0.2 mg/ml. However, no mutagenic effect was demonstrated in the in vivo study up to 2000 mg/kg. No significant reduction in the polychromatic and normochromatic erythrocytes ratio was noted in any of the groups. Meanwhile, high micronucleated polychromatic erythrocytes frequency was seen in cyclophosphamide-treated group only. These findings could perhaps be due to insufficient dosage of A. hierochuntica aqueous extracts to cause genetic damage on the bone marrow target cells. Further acute and chronic in vivo toxicity studies may be required to draw pertinent conclusion on the safety aspect of A. hierochuntica aqueous extracts consumption. Impact statement In this paper, we report on the mutagenicity evaluation of Anastatica hierochuntica aqueous extract. This is a significant research in view of the popularity of this herb consumption by the people across the globe despite of limited scientific evidence on its toxicity potential. This study is intended to encourage more extensive related research in order to provide sufficient evidence and guidance for determining its safe dosage.

scholarly journals A Novel 3-Deoxy-d-manno-Octulosonic Acid (Kdo) Hydrolase That Removes the Outer Kdo Sugar of Helicobacter pylori Lipopolysaccharide

2005 ◽  
Vol 187 (10) ◽  
pp. 3374-3383 ◽  
Author(s):  
Christopher Stead ◽  
An Tran ◽  
Donald Ferguson ◽  
Sara McGrath ◽  
Robert Cotter ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Lipid A ◽  
In Vitro Assay ◽  
Spectrometric Analysis ◽  
Vitro Assay ◽  
The Core ◽  
H Pylori

ABSTRACT The lipid A domain anchors lipopolysaccharide (LPS) to the outer membrane and is typically a disaccharide of glucosamine that is both acylated and phosphorylated. The core and O-antigen carbohydrate domains are linked to the lipid A moiety through the eight-carbon sugar 3-deoxy-d-manno-octulosonic acid known as Kdo. Helicobacter pylori LPS has been characterized as having a single Kdo residue attached to lipid A, predicting in vivo a monofunctional Kdo transferase (WaaA). However, using an in vitro assay system we demonstrate that H. pylori WaaA is a bifunctional enzyme transferring two Kdo sugars to the tetra-acylated lipid A precursor lipid IVA. In the present work we report the discovery of a Kdo hydrolase in membranes of H. pylori capable of removing the outer Kdo sugar from Kdo2-lipid A. Enzymatic removal of the Kdo group was dependent upon prior removal of the 1-phosphate group from the lipid A domain, and mass spectrometric analysis of the reaction product confirmed the enzymatic removal of a single Kdo residue by the Kdo-trimming enzyme. This is the first characterization of a Kdo hydrolase involved in the modification of gram-negative bacterial LPS.

Carcinogenic and co-carcinogenic potential of 2,3,7,8-tetrachlorodibenzodioxin in a host-mediated in vivo/in vitro assay

Chemosphere ◽  
1992 ◽  
Vol 25 (7-10) ◽  
pp. 1085-1090 ◽  
Author(s):  
T. Massa ◽  
A. Esmseili ◽  
H. Fortmeyer ◽  
B. Schlatterer ◽  
H. Hagenmaier ◽  
...  
Keyword(s):  
In Vitro Assay ◽  
Vitro Assay ◽  
Carcinogenic Potential

scholarly journals Ruminal fermentation and digestion of cattle diets with total and partial replacement of soybean meal by a slow-release urea product

2019 ◽  
Vol 64 (No. 7) ◽  
pp. 294-301
Author(s):  
S Gonzalez-Munoz ◽  
J Sanchez ◽  
S Lopez-Aguirre ◽  
J Vicente ◽  
J Pinos-Rodriguez
Keyword(s):  
Soybean Meal ◽  
Degradation Rate ◽  
Slow Release ◽  
In Vitro Assay ◽  
Partial Replacement ◽  
Vitro Assay ◽  
Dietary Substitution ◽  
Slow Release Urea

One in vitro assay and one in vivo trial with ruminally cannulated Holstein steers were conducted to evaluate the effects of a dietary substitution of soybean meal by a urea and slow-release urea source of fermentation and degradation of diets for cattle. The experimental diets consisted of the total mixed rations defined as the control with soybean meal (SBM), U (urea), SRU (slow-release urea), and SRU+U+AA (0.42% + 0.42% + 1% amino acids methionine and lysine). The dietary substitution of SBM by U or SRU reduced (P < 0.05) the total gas production (V), microbial mass and degradation at 72 h incubation under the in vitro conditions, as well as the degradation rate (c) and the total volatile fatty acids (VFA) in the rumen of the steers; however, when the dietary substitution of SBM was by U+SRU+AA, those values did not decrease. In the steers, the dietary substitution of SBM by U and SRU reduced the ruminal degradation rate and the total VFA, and increased the ammonia N, but when SBM was substituted by U+SRU+AA in the diets, these changes were not observed. No advantage of SRU over U was found. The dietary substitution of SBM by U, SRU, U+SRU+AA did not modify the molar proportion of the VFA in the rumen nor were there changes in the nutrient digestion or excretion. Both the in vitro assay and the in vivo trial indicated that replacing SBM with U or SRU increases the ruminal ammonia N concentrations and reduces the degradation rate in the rumen, although those undesirable findings were not found when the SBM was replaced by U+SRU+AA. Therefore, it is feasible to replace the SBM with a combination of urea, slow-release urea, lysine and methionine in the diet for the ruminants.

scholarly journals In Vivo and In Vitro Assay for Drug Effect on Cancer Cells

1963 ◽  
Vol 157 (5) ◽  
pp. 785-797 ◽  
Author(s):  
G. O. McDonald ◽  
A. N. Stroud ◽  
A. M. Brues ◽  
W. H. Cole
Keyword(s):  
Cancer Cells ◽  
Drug Effect ◽  
In Vitro Assay ◽  
Vitro Assay
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