Sulfonium compounds, C11-14-alkylbis(hydroxyethyl), 2-hydroxyethyl sulfates (salts)

Endpoint summary

Description of key information

NOAEL(oral, OECD 422) = 30 mg/kg bw/day (CiTox LAB Hungary, 2013)

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

NOAEL

30 mg/kg bw/day

Study duration:

subacute

Species:

rat

Additional information

A Combined Repeated Dose Toxicity Study with the Reproduction/Developmental Toxicity Screening Test was performed to obtain information on the toxicity of the test item following repeated (daily) administration by oral gavage to Wistar rats at 3 dose levels. The study was conducted according to OECD 422 guideline and GLP (CiToxLab, 2013).

The study also included a reproductive/developmental toxicity-screening test, intended to provide initial information on possible effects on male and female reproductive performance such as gonadal function, mating behaviour, conception, pregnancy, parturition and also on the development of the F1 offspring from conception to Day 4 post-partum. 

Male and female Wistar rats (12 animals per sex and dose level) were treated for 2 weeks pre-mating, then during the mating/postmating period, males for 29 days and females throughout gestation period, up to and including postpartum/lactation Day PPD4. The dose level were 0, 30, 100 and 300 mg/kg bw/day. The control animals were treated with the vehicle only (distilled water).

Parameters measured during the study included signs of morbidity and mortality twice daily, daily or detailed weekly observation of clinical signs, neurological assessment, at least weekly body weight and food consumption, and clinical pathology evaluation, including haematology, coagulation and clinical chemistry. In addition, the reproductive performance and indices, pregnancy, parturition and postpartum/lactation period were monitored in the adult animals, and viability, clinical signs and development were evaluated in their F1 offspring until PND4. At termination, necropsy with macroscopic examination was performed. Selected organs were subjected to histopathology examination.

Analysis of test item formulations for concentration and homogeneity was performed three times during the treatment period (during the second, fourth and last weeks of treatment), using validated ICP/AES method. All formulations were found to be in the range of 92 to 99% of nominal concentration and were homogeneous. No test item was detected in the control samples. Based on these results, the test item formulations were considered suitable for the study purposes.

Results

 

One High dose male treated at 300 mg/kg bw/day was found dead on Day 14.

No cause of death was established for this animal, although the causative role of the test item cannot be excluded as characteristic test item related changes were noted in the stomach and adrenals in addition tomeningoencephalomyelitis noted microscopically.

 

Clinical signs were limited to slightly decreased activity and soft/liquid faeces noted in 2 of 12 females at 300 mg/kg bw/day and were occasionally observed towards the end of the treatment period. No clinical signs were noted for males, with the exception of clinical signs preceded death of the High dose male (hunched position, piloerection, liquid faeces and red nasal discharge).

 

During neurological assessment, slight differences were recorded for animals treated at 300 mg/kg bw/day. Compared to controls, lower values in the grip strength tests were recorded for both males and females and in landing foot splay tests for females. Taking into account the small magnitude of the effects, these differences were considered to be attributable to general toxicity and not to represent neurotoxicity. No effect was observed in motor activity investigation.

 

Transient slight body weight loss was observed at 300 mg/kg bw/day in males and in some of the females. In spitehigher body weight gain during Week 2, the body weights of males were consistently lower than the controls. The mean terminal body weight was approximately 3% lower,and overall body weight gain was reduced by 21%.

Females hadlower body weight gain during the premating period (by 20%) andentire gestation period (by 26%).This resulted in lower mean body weight on GD 20 (by 10%) and Post Partal Days 0 and 4 (by 15%).

 

Food consumption was decreased at 300 mg/kg bw/day in both males and females.

 

There was no effect of treatment on haematology parameters in males.

In females marked decreases in erythrocyte counts, hemoglobin concentration and haematocrit were recorded for 1/5 High and 1/5 Mid dose animals. The changes were accompanied by increased reticulocyte counts. In addition, both animals had increased relative neutrophil granulocyte and decreased relative lymphocyte counts.

Mild changes in clinical chemistry parameters consisted of slight increase inalanine aminotransferase activityin both sexes at 300 mg/kg bw/day, slightly elevated serum urea concentration in males andlower serum glucose level in femalesin the High and Mid dose. 

 

There was no effect of treatment noted during evaluation of the reproductive parameters,however increasedintrauterine and postnatal mortality values,lower number of born pupsandincreased mortality of pupswere noted at100 and 300 mg/kg bw/day and were attributed to 4/12 Mid dose and 5/12 High Dose dams.

 

Pups born at300 mg/kg hadslightly lower body weighton postnatal Days 0 and 4, but body weight gain until postnatal Day 4 was comparable with controls.

 

There were no adverse effects on the F1 offspring clinical signs or development.

 

At necropsy,thick mucosa of the non-glandular region part of the stomach was noted in all males and in 10 of 12 females at 300 mg/kg bw/day and in 8 of 12 males and in 3 of 12 females at 100 mg/kg bw/day and was related tominimal to moderate parakeratotic hyperkeratosis occasionally associated with influx of mixed cell infiltrate/inflammation, ulceration or erosion predominantly in the High dose group.In one High dose female multifocal, necrotizing ulceration in the cecum and focal capsular fibrosis in the liver was found.

 

In the adrenal glands bilateral minimal to mild diffuse hypertrophy of cortical cells in the zona fasciculata was noted in 3/24 Mid and 6/23 High dose ratsandcorresponded with organ weight changes and with macroscopic observations (enlargement).

 

Minimal to moderate lymphoid atrophy was found in thymus in 1/24 Mid and 7/23 High Dose rats.

 

Conclusion

 

Administration of the test itemsulfonium compounds, C11-14-alkylbis (hydroxyethyl), 2-hydroxyethyl sulfates (salts) ata dose levels of 30, 100 and 300 mg/kg body weight/day to Wistar rats for at least 29 consecutive days was associated with the following relevant findings:

 

Treatment at 300 mg/kg bw/day caused transient body weight loss (most pronounced in males) andreduction of body weight gain by21% inmales and in females by approximately 20-26% during premating and gestation periods,mild changes in clinical chemistry parameters (slight increase inalanine aminotransferase activityin both sexesslightly elevated serum urea concentration in males andlower serum glucose level in females)minimal to moderate parakeratotic hyperkeratosis occasionally associated with influx of mixed cell infiltrate/inflammation, ulceration or erosion in stomach, hypertrophy of cortical cells in the zona fasciculate of adrenal glands corresponding to enlargement of adrenals and lymphoid atrophy in the thymus.An increasedintrauterine and postnatal mortality,lower number of born pups,increased mortality and lower body weight of pupswere considered to be probably secondary to maternal toxicity.

 

Treatment at 100 mg/kg bw/day caused parakeratotic hyperkeratosis changes in mucosa of stomach, hypertrophy of cortical cells in the zona fasciculate of adrenal glands and thymus atrophy. Increase intrauterine and postnatal mortality,lower number of born pups andincreased mortality of pupswere considered to be probably secondary to maternal toxicity.

 

No adverse effects or test item related findings were observed at the low dose level (30 mg/kg bw/day.

 

In conclusion, for systemic and developmental toxicity as well as local effects, the NOAEL of sulfonium compounds, C11-14-alkylbis (hydroxyethyl), 2-hydroxyethyl sulfates (salts) administered by the oral route to Wistar rats for at least 29 consecutive days is considered to be the low-dose level of 30 mg/kg bw/day.

 

The NOAEL for reproductive performance and fertility was 300 mg/kg bw/d in male and female Wistar rats.

Range-Finder:

The study was designed to obtain preliminary information on the toxicity of the test item administered by oral gavage to Wistar rats at three dose levels for 14 consecutive days and to allow selection of appropriate dose levels for use in a subsequent Combined Repeated Dose Toxicity Study with the Reproduction/Developmental Toxicity Screening Test (OECD 422).

Male and female Wistar rats were treated at dose levels of 0, 30, 100 and 300 mg/kg bw orally by gavage. The test item was formulated indistilled water and the control group was treated with the vehicle only.

 

The dose formulations were of adequate concentration to meet the study objectives. The measured concentrations were within the 90-102%.

 

Mortality and clinical observations were performed twice daily. Body weight and food consumption were measured on Days 0, 3, 6 and 13 with a fasted body weight recorded prior to scheduled necropsy on Day 14. Following repeated dose administration daily for 14 days, blood samples were collected for clinical pathology terminally. Gross macroscopic examination was performed at necropsy one day after the last treatment. Selected organs were weighed. No histopathology examination was performed.

There were no clinical signs or unscheduled mortality during the study.

 

Transientbody weight gain suppression or slight body weight loss was observed in males at 300 mg/kg bw/day between Days 0-6. Although slight body weight gain was noted between Days 6-13, the mean body weight was lower by approximately 9% at the termination of the treatment period. Theaverage food consumption was lower than control and was in accordance with body weight changes.

In females at300 mg/kg,body weight and body weight gain values werecomparable to the control, exceptweight gain values between Days 6-10, when slight body weight loss or body weight gain suppression was noticed.

 

There were no adverse effects in the investigated haematology parameters at any dose level, however slightly lower (approximately 5%)haemoglobin concentration and haematocrit values were recorded for females at 300 mg/kg bw/day, when compared with the control means.

Higher than control serum alanine aminotransferase (ALT) activity and lower total protein and albumin concentrations were noted in both males and females at 300 mg/kg bw/day and in males at 30 mg/kg.The values were within the physiological range.

In addition slight increases in the potassium (K+) concentrations were recorded for both males and females at 300 mg/kg bw/day, when compared to controls.

 

Test item-related macroscopic changes were observed at necropsy in both males and females at 300 mg/kg bw/day (High dose) and in males at 100 mg/kg bw/day (Mid dose). The changes consisted of thick mucosa with raised areas in the non-glandular region of the stomach, noted in all high dose animals and in 3 of 4 mid dose males. The change was diffuse in the high dose animals and focal in mid dose males.

 

Compared to the control means, males at 300 mg/kg bw/day had higher relative liver weights (by approximately 14%) and lower seminal vesicle weight (by approximately 19-25%). 

 

Infemales, lower kidneyweights were measuredat 100 and 300 mg/kg bw/day, whencompared to the control means. The differences were in the range of 7-13% and were found inabsolute and relative values (adjusted for both brain and terminal body weight).

Conclusion

Administration of Sulfonium compounds, C-11-14-alkylbis (hydroxyethyl), 2-hydroxyethyl sulfates (salts) to Wistar rats by oral gavage, daily for 14 days, was associated at a dose level of 300 mg/kg bw/day with temporary effect on body weightin males during the first week of the treatment period(body weight gain suppression or slight body weight loss), a slight decrease in haemoglobin concentration and haematocrit values in females,a minimal increase in ALT activity and higher potassium concentrationin both sexes and macroscopic changes in the stomach of both sexes in the form of thick mucosa of the non-glandular region.

 

At 100 mg/kg bw/day slight macroscopic changes in the stomach were observed in 3 of 4 males only.

 

In consultation with the Sponsor, the dose levels considered suitable for a subsequentCombined Repeated Dose Toxicity Study with the Reproduction/Developmental Toxicity Screening Test in the rat were 300, 100 and 30 mg/kg bw/day,as the High, Mid and Low Dose respectively,at a dose volume of 10 mL/kg.

BASF, XXV/469, 1977:

During a 28 day study performed according to a BASF internal standard protocol similar to OECD TG 407, groups of 20 rats per sex and dose were treated orally by feed with 0, 100, 300, 1000 or 3000 ppm of Antistatikum 743 daily for 4 weeks. 10 rats per sex and dose were sacrificed after the exposure time while the others were observed for 2 more weeks. For all treated animals clinical signs, food consumption, body weights and mortality were documented as well as effects regarding clinical chemistry, haematology, urine parameter, organ weights, histology and pathology.

The treated animals did not show clinical signs and no moratlities were reported. No test item-related changes of haematological and clinico-chemical parameters or macroscopical organ morphology were detected.

At the end of the exposure period male and female animals treated with 3000 ppm showed an decreased food consumption which resulted in decreased body, absolute heart, kidney, spleen, and testis weights of the males. These effects were reversible during the postexposure period and therefore not biologically relevant.

An biologically relevant increase in the relative liver weights were detected in male animals dosed with 1000 and 3000 ppm as well as female animals treated with 3000 ppm. Additionally increased relative adrenal gland weights were found in male animals of all dose groups without histopathological findings. The high dose group showed very slight microvesicular steatosis of liver and kidney which were fully reversible within the 14 days postexposure period. The intracellular storage of the test item was not detected. A slightly increased amount of lipids was detected in the adrenal gland but was not assumed to be biologically relevant. Elevated levels of eosinophiles or eosinophile myelocytes including slight siderosis were detected in spleens and mesenterial lymph nodes of the high dose-treated rats, mainly in females, which was assumed to be an adaptive effect.

At the end of the postexposure period the absolute weights of heart, liver and kidney were elevated in male animals of all dose groups. Furthermore, the relative liver weights were increased in all male rats of the 1000 and 3000 ppm group. This was not assumed to be a test item-related effect but a consequence of the increased food consumption and body weight during the postexposure period.

In conclusion, the treatment with 3000 ppm of the test item caused adaptive, non-adverse effects. Therefore the NOAEL of the test item under the conditions of the present study was set to 3000 ppm.

BASF, XXI/132, 1972:

In a 28 day study conducted according to a BASF internal standard protocol similar to OECD TG 407, groups of 10 rats per sex and dose were treated orally by feed with 0, 3000 or 6000 ppm of Antistatikum 743 daily for 4 weeks. For all treated animals clinical signs, food consumption, body weights and mortality were documented as well as effects regarding clinical chemistry, haematology, urine parameter and organ weights.

The treated animals did not show clinical signs, mortality or changes in clinico-chemical parameters.

Females and males treated with 6000 ppm showed significantly reduced body weights. Furthermore the absolute weights of heart, liver, kidney, and spleen were decreased. These effects were consequences of a significantly decreased food uptake. An elevated activity of serum-glutamate-pyruvate transaminase were detected in males and females treated with 6000 ppm while the activity of alcaline phosphatase as well as blood urea were increased in males treated with 3000 and 6000 ppm and females treated with 6000 ppm.

Increased relative liver and testis weights were reported for males of the high dose group while females treated with 3000 and 6000 ppm developed increased relative liver weights. Histopathological examinations were not performed during this study.

Justification for classification or non-classification

Based on the available data classification and labeling according to Directive 67/548/EEC (R48/22) and CLP (STOT Repeated Cat. 2) is required.