Propiononitrile

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2009

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Data source

Reference

Reference Type:

publication

Title:

Acute toxicity of some synthetic cyanogens in rats and their response to oral treatment with alpha-ketoglutarate

Author:

R. Bhattacharya
R.M. Satpute
J. Hariharakrishnan
H. Tripathi
P.B. Saxena

Year:

2009

Bibliographic source:

Bhattacharya, R. et al., 2009. Acute toxicity of some synthetic cyanogens in rats and their response to oral treatment with alpha-ketoglutarate. Food and Chemical Toxicology, 47(9), pp.2314–2320

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)

GLP compliance:

not specified

Remarks:

Study was published in 2009, but conducted earlier outside the EU, and test was not commissioned by the registrant, and was not performed specifically for REACH

Test type:

acute toxic class method

Test material

Test material information

Constituent 1

Reference substance name:

Propiononitrile

EC Number:

203-464-4

EC Name:

Propiononitrile

Cas Number:

107-12-0

Molecular formula:

C3H5N

IUPAC Name:

propanenitrile

Specific details on test material used for the study:

Purchased from Acros Organics, New Jersey, USA

Test animals

Species:

rat

Strain:

Wistar

Sex:

female

Details on test animals or test system and environmental conditions:

emale Wistar rats (150–200 g) bred in the animal facility of Defence Research and Development Establishment (DRDE), Gwalior were maintained on a bedding of rice husk in polypropylene cages. Animals had access to water and rodent pellet feed (Ashirwad Brand, Chandigarh, India) ad libitum. Feed was withdrawn 4 h prior to experiment and animals had access to feed 2 h post-exposure. The study was approved by the establishment’s ethical committee on animal experimentations.

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Control animals:

yes

Details on study design:

All the solutions were prepared fresh in triple distilled water. Solutions of A-KG or various cyanogens were administered orally using a 16 gauge animal feeding needle (HSE-Harvard, Germany). 24 h oral LD50 of different cyanogens in the ab- sence or presence of A-KG was determined by Dixon’s up and down method (Dixon,1965), using 4–6 rats for each LD50 determination. Rats received A-KG (oral; 2.0 g/ kg) 10 min after SNP, 30 min after SCN, and 2 h after MCN, ACN, PCN and ATCN. Pro- tection index was calculated as the ratio of LD50 of cyanogens in the presence or ab- sence of A-KG. The dose of A-KG was selected on the basis of our previous studies (Bhattacharya and Vijayaraghavan, 2002; Bhattacharya et al., 2002). Among several doses tested, 2.0 g/kg A-KG was found to provide the maximum protection against acute cyanide poisoning in rodents. The time of A-KG administration for different cyanogens was decided on the basis of time required for onset of various signs and symptoms as observed during our preliminary studies. Out of six cyanogens evaluated, A-KG conferred significant protection against MCN, PCN and SNP alone. Further studies were carried out with 0.75 LD50 of these cyanogens only. In a sep- arate study, 48 rats were randomized into eight groups of six animals each and trea- ted as follows: (1) control (triple distilled water); (2) A-KG (2.0 g/kg), (3) MCN (52.4mg/kg), (4) PCN (92.1mg/kg), (5) SNP (52.4mg/kg), (6) MCN+A-KG, (7) PCN + A-KG and (8) SNP + A-KG. Twenty four hours after treatment, animals were weighed and 2 ml of blood was drawn from the retro-orbital plexus of each animal under ether anesthesia. Various hematological and biochemical parameters were measured in the heparinized blood. Soon after, animals were killed by cervical dis- location. The brain, heart, lung, liver, kidney and spleen were excised quickly, rinsed in 0.9% saline, blotted and weighed to determine the organ-body weight index, which was calculated as the ratio of organ weight 100 and the animal body weight.

Hematological and biochemical parameters
Various hematological parameters viz. white blood cells, red blood cells, hemat- ocrit, mean cell volume, mean cell hemoglobin concentration, mean cell hemoglo- bin, platelet and hemoglobin were measured by automated blood analyzer (Beckman-Coulter, USA). Blood glucose (mg/dl), plasma creatinine (mg/dl), alanine aminotransferase (ALT; U/L) and aspartate aminotransferase (AST; U/L) were mea- sured on UV visible spectrophotometer (Thermo Electron Corpn., USA), using Eco- line diagnostic kit of Merck (India). Plasma LDH (U/L) was measured by the method of Welder and Acosta (1993). Plasma levels of Na+ and K+ ions (meq/L) were estimated using 128 Systronics (India) flame photometer. Concentrations of cyanide (lg/dl) and thiocyanate (lg/ml) in plasma were measured by ion selective elec- trodes using Orion 9458 BN and Orion 9606 BN, respectively of Thermo Electron Corp. (USA). Prior to cyanide estimation plasma was subjected to microdiffusion in Conway cells (Yagi et al., 1990).
In addition to the above, various biochemical assays were performed in the brain, liver and kidney homogenate. Antioxidant enzymes like glutathione peroxi- dase (GPx; lmol NADPH/oxidized/min/mg protein), glutathione reductase (GR; mmol NADPH oxidized/min/mg protein) and catalase (CA; mmol H2O2 degraded/ min/mg protein) were measured following the method of Flore and Gunzler (1984), Paolo et al. (1986) and Aebi (1974), respectively. Superoxide dismutase (SOD; IU/100 mg wet tissue) was estimated by SOD assay kit of Calbiochem (Ger- many). Reduced glutathione (GSH) and oxidized glutathione (GSSG) were estimated by the method of Hissin and Hilf (1976) and expressed as lmol/g wet tissue. Lipid peroxidation was assessed by measuring malondialdehyde (MDA) levels in soft tis- sues and the values expressed as nmol/g wet tissue (Okhawa et al., 1979). Cyto- chrome oxidase (CYTOX) was measured by the method of Cooperstein and Lazarow (1951), and expressed as nmol cytochrome c oxidized/min/mg protein. Protein levels in the tissue homogenate were estimated by the method of Lowry et al. (1951). Activity of rhodanese enzyme was estimated in liver homogenate by the method of Westley (1981), and the values expressed as lg thiocyanate formed/min/g tissue. To assess the DNA damage in the tissues, DNA was isolated by phenol:chloroform method and electrophoresed on 1.2% agarose gel (Sambrook and Russell, 2001).

Statistics:

The results are expressed as mean ± SEM (n = 6). The data were analyzed by one way ANOVA followed by Dunnet’s test using SigmaStat software (Jandel Scientific Inc., USA). Statistical significance was estimated at the 5% level.

Results and discussion

Effect levels

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

122.9 mg/kg bw

Based on:

test mat.

Mortality:

Death occurred after 4-6 hours.

Clinical signs:

other: Convulsions, lethargy, shallow respiration, restlessness, splaying of hind limbs and loss of righting reflex were some of the symptoms preceding death.

Other findings:

The white blood cells ( 103/ll), red blood cells ( 106/ll), hematocrit (%), mean cell volume (fL), mean cell hemoglobin concentration (g/dl), mean cell hemoglobin (pg), platelet ( 103/ll) and hemo- globin (g/dl) levels in control rats were 22.8 ± 1.18, 7.98 ± 0.53, 37.5 ± 1.62, 49.7 ± 2.22, 33.5 ± 0.39, 16.7 ± 0.96, 909 ± 83 and 12.6 ± 0.59, respectively. None of the parameters were affected by cyanogens.

Applicant's summary and conclusion

Interpretation of results:

Category 3 based on GHS criteria

Conclusions:

A 24-hour study of various substances including propionitrile was conducted on rats. For propiontrile, the LD50 was 122.9 mg/kg bw, leading to an Acute Tox. 3 classification according to the CLP guidelines.