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Toxicological information

Repeated dose toxicity: oral

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Administrative data

Endpoint:
sub-chronic toxicity: oral
Type of information:
read-across based on grouping of substances (category approach)
Adequacy of study:
key study
Study period:
1976
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Acceptable study, followed scientific principles/standards, pre-dates GLP
Remarks:
.Published study included for completeness
Justification for type of information:
Category Approach; test material is reference substance LAS. LAS provides suitable read across for LAB Sulfonic Acids as both form the identical chemical species in aqueous solutions at neutral (physiological) pH, namely, the LAS ion (C10-13linear alkyl benzene-SO3-) and would be expected to have similar toxicological properties.
Cross-reference
Reason / purpose:
reference to same study

Data source

Reference
Reference Type:
publication
Title:
Unnamed
Year:
1976

Materials and methods

Principles of method if other than guideline:
The purpose of this study is to determine the sub chronic toxicity of LAS in Wistar JCL rats, focusing on the liver and kidneys. Male and female rats were maintained on either test diets (0, 0.6 and 1.8%) or drinking water (0, 0.07 and 0.2%) for 9 months. 0.6 and 1.8% rats in drinking water study exhibited severe weight loss so LAS administration was stopped after 2 weeks. Mortality, clinical observations and body weights were recorded during the study. All the surviving animals were humanely euthanized at end of 9 months and gross necropsy, hematological, serum biochemical tests, enzyme tests on the liver and kidneys were performed and organs weights were measured. No histopathology was performed.
GLP compliance:
no
Remarks:
(pre-dates GLP)
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
not specified
Details on test material:
Name of test material: LAS (Linear alkylbenzene sulfonate); NeoPlex P-60
No further details on test substance are provided in study report.

Test animals

Species:
rat
Strain:
other: Wistar JCL
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Male and female rats were obtained from Shizuoka Agricultural Cooperative Association for
Laboratory Animals
- Age at study initiation: 4-weeks old
- Weight at study initiation: 100 - 124 g (male rats), 82 - 100 g (female rats)
- Fasting period before study: No
- Housing: 5 animals were housed per cage.
- Diet: CE-2 food (from CLEA Japan); ad libitum
- Water: ad libitum
- Acclimation period: 1 week before the start of treatment

ENVIRONMENTAL CONDITIONS
- Temperature: 25 ± 1°C
- Humidity: 50 - 60%
- Air changes: Not reported
- Photoperiod: 12 hours dark /12 hours light

IN-LIFE DATES: Not reported

Administration / exposure

Route of administration:
other: oral: drinking water and feed
Details on route of administration:
LAS was administered to animals by mixing 0.6 and 1.8% in CE-2 food (CLEA Japan) and dissolving to 0.07 and 0.2% in drinking water.
Vehicle:
other: Test substance was administered either in diet or drinking water
Analytical verification of doses or concentrations:
no
Duration of treatment / exposure:
9 months
Frequency of treatment:
Continuous in diet or drinking water (ad libitum)
Doses / concentrationsopen allclose all
Dose / conc.:
0.6 other: %
Remarks:
in diet
Dose / conc.:
1.8 other: %
Remarks:
in diet
Dose / conc.:
300 mg/kg bw/day (nominal)
Remarks:
in diet (corresponding to 0.6% dose level)
Dose / conc.:
900 mg/kg bw/day (nominal)
Remarks:
in diet (corresponding to 1.8% dose level)
Dose / conc.:
0.07 other: %
Remarks:
in drinking water
Dose / conc.:
0.2 other: %
Remarks:
in drinking water; 0.6 and 1.8% dose group (equivalent to 857.14 and 2571.43 mg/kg bw/day) were also included, however due to severe weight loss so LAS administration was stopped after 2 weeks.
No. of animals per sex per dose:
Feeding study (mixed in diet): 8 animals/sex/dose
Drinking water study: 9 animals/sex/dose
Control animals:
yes, concurrent vehicle
yes, plain diet
Positive control:
No

Examinations

Observations and examinations performed and frequency:
CLINICAL OBSERVATIONS: Yes
- Time schedule: Weekly

BODY WEIGHT: Yes
- Time schedule for examinations: Weekly

FOOD CONSUMPTION AND COMPOUND INTAKE:
- Food consumption: Yes
- Compound intake: Yes
- Time schedule for examinations: Weekly

FOOD EFFICIENCY: No

WATER CONSUMPTION AND COMPOUND INTAKE: Yes
- Time schedule for examinations: Weekly

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY: Yes
- Time schedule for collection of blood: After 9 months, blood was collected from each animal after euthanizing.
- Anesthetic used for blood collection: No
- Animals fasted: Not specified
- How many animals: Not specified
- Parameters: White blood cells (WBC), red blood cells (RBC), Hemoglobin (Hgb), Hematocrit (Hct), mean corpuscular volume (MCV) and mean corpuscular hemoglobin concentration (MCHC)

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: After 9 months, blood was collected from each animal after euthanizing.
- Animals fasted: Not specified
- How many animals: Not specified
- Parameters: Glutamate oxaloacetate transaminase (GOT), glutamate pyruvic transaminase (GPT), glucose content, urea nitrogen, total cholesterol, albumin, alkaline phosphatase (ALP) and cholinesterase

URINALYSIS: No

NEUROBEHAVIOURAL EXAMINATION: No

IMMUNOLOGY: No

OTHER:
- Liver enzyme tests: Glucose 6-phosphatase (G6Pase), lactase dehydrogenase (LDH) and G6P-DH activity
- Kidney enzyme tests: G6Pase, LDH, GPT, GOT, ALP, acid phosphatase (ACP), Na, K-ATPase, and malate dehydrogenase (MDH)
Sacrifice and pathology:
GROSS PATHOLOGY: Yes (However, no details in study report in mentioned)
Gross findings were obtained after euthanizing animals and organs were removed for organ weight measurements.

ORGAN WEIGHTS: Brain, heart, lungs, liver, spleen, kidneys, adrenal gland, testes, ovary, uterus, and appendix
HISTOPATHOLOGY: No

Results and discussion

Results of examinations

Clinical signs:
effects observed, treatment-related
Description (incidence and severity):
Both female and male rats (drinking water study) exhibited a slight redness at the tips of their facial fur, and coarse fur all over their bodies.
Mortality:
no mortality observed
Body weight and weight changes:
effects observed, treatment-related
Description (incidence and severity):
There was significant decrease in body weight gain in males and females of 1.8% dose group fed with diet and in males of 0.2% dose group consuming LAS contained water.
Food consumption and compound intake (if feeding study):
no effects observed
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
effects observed, treatment-related
Description (incidence and severity):
Increased water consumption was observed in males of 1.8% dose group fed with diet and 0.2% dose group consuming LAS contained water.
Ophthalmological findings:
not examined
Haematological findings:
effects observed, treatment-related
Description (incidence and severity):
A significant reduction in WBC was observed in 0.6% (diet) male rats and in MCV and MCH was observed in 1.8% (diet) female rats compared to controls.
Clinical biochemistry findings:
effects observed, treatment-related
Description (incidence and severity):
There were significant alteration in cholesterol [decrease; all doses, except female rats of 0.07% dose group (drinking water)], GPT [0.6% dose group (diet) females)], GOT [1.8% dose group (diet) males], albumin [1.8% (diet) males] , ALP levels [male and female rats fed with 1.8% LAS-diet] and cholinesterase levels [in male rats fed with 1.8% LAS-diet].
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Immunological findings:
not examined
Organ weight findings including organ / body weight ratios:
effects observed, treatment-related
Description (incidence and severity):
In males of 1.8% (diet), the absolute liver and testes weight was significantly decreased and the relative testes and liver weight was significantly increased and both absolute and relative spleen weight were also significantly reduced.
In females of 1.8% (diet), absolute and relative liver and caecum weight was significantly increased.
There was also significant decrease in absolute and relative heart weight in females of 0.6% (diet) and 0.07% (drinking water) dose groups.
Gross pathological findings:
not specified
Neuropathological findings:
not examined
Histopathological findings: non-neoplastic:
not examined
Histopathological findings: neoplastic:
not examined
Other effects:
effects observed, treatment-related
Description (incidence and severity):
Liver enzyme tests:
Dietary study: G6Pase activity was reduced in 1.8% dose group males and females, G6P-DH activity was reduced in 0.6 and 1.8% dose group males and females, LDH activity was reduced in 0.6, 1.8% dose group. GOT and GPT activities were clearly reduced in males, while in females GPT activity was reduced only in 1.8% dose group and GOT activity was reduced in 1.8% dose group animals.
Drinking water study: LDH activity was reduced in 0.2% dose group males. GOT and GPT activities were clearly reduced in males and GOT activity was increased in 0.07 and 0.2% dose group animals.

Renal enzyme tests:
Dietary study: A significant difference was also observed in G6Pase activity. In females, G6Pase, Na, K-ATPase, and LDH activity were significantly reduced in 1.8% dose group (diet) animals
Drinking water study: In males, Na, K-ATPase activity was significantly reduced in 0.2% dose group. A significant difference was also observed in G6Pase activity.
Details on results:
CLINICAL SIGNS: Both female and male rats consuming LAS-containing water exhibited a slight redness at the tips of their facial fur, and coarse fur all over their bodies.

BODY WEIGHT AND WEIGHT CHANGES: There was significant decrease in body weight gain in male and females of 1.8% dose group fed with diet and in males of 0.2% dose group consuming LAS contained water.

WATER CONSUMPTION AND COMPOUND INTAKE: Increased water consumption was observed in males of 1.8% dose group fed with diet and 0.2% dose group consuming LAS contained water.

HAEMATOLOGICAL FINDINGS: A significant reduction in WBC was observed in 0.6% (diet) male rats compared to controls, and a significant reduction in MCV and MCH was observed in 1.8% (diet) female rats compared to controls.

CLINICAL BIOCHEMISTRY: Except female rats of 0.07% dose group (drinking water), a significant reduction or a reduction in cholesterol was observed in male and female rats of all dose groups compared to controls. GPT was significantly reduced in 0.6% dose group (diet) females, and reduced in females of other treatment groups. GOT was significantly reduced in 1.8% dose group (diet) males, and reduced in both females and males of other treatment groups. Albumin was significantly reduced in 1.8% (diet) males and reduced in males of 0.2% dose group (drinking water) and females of 1.8% dose group (diet). There was significant increase in ALP levels in male and female rats fed with 1.8% LAS-diet and cholinesterase levels in male rats fed with 1.8% LAS-diet.

ORGAN WEIGHT: In males of 1.8% (diet), the absolute liver and testes weight was significantly decreased and the relative testes and liver weight was significantly increased and both absolute and relative spleen weight were also significantly reduced. In females of 1.8% (diet), absolute and relative liver and caecum weight was significantly increased. There was also significant decrease in absolute and relative heart weight in females of 0.6% (diet) and 0.07% (drinking water) dose groups.

LIVER ENZYME TESTS: G6Pase activity was reduced in 1.8% dose group (diet) males and females, G6P-DH activity was reduced in 0.6 and 1.8% dose group (diet) males and females, where the percentage reduction was greater in 1.8% dose group (diet) animals. LDH activity was clearly reduced in 0.6, 1.8% dose group (diet), and 0.2% dose group (drinking water) males, but reduced in only 1.8% dose group (diet) females. GOT and GPT activities were clearly reduced in males, while in females GPT activity was reduced only in 1.8% dose group (diet) animals, and GOT activity was increased in 0.07 and 0.2% dose group (drinking water) animals but reduced in 1.8% dose group (diet) animals.

RENAL ENZYME TESTS: In males, Na, K-ATPase activity was significantly reduced in 0.2% dose group (drinking water) animals, and also reduced in other male treatment groups. A significant difference was also observed in G6Pase activity, where the reduction observed was associated with an increase in amount consumed. In females, G6Pase, Na, K-ATPase, and LDH activity were significantly reduced in 1.8% dose group (diet) animals, and G6Pase and LDH activity were also reduced in other treatment groups.

Effect levels

open allclose all
Key result
Dose descriptor:
LOAEL
Effect level:
300 mg/kg bw/day (nominal)
Based on:
act. ingr.
Remarks:
(dietery study)
Sex:
male/female
Basis for effect level:
clinical signs
body weight and weight gain
water consumption and compound intake
haematology
clinical biochemistry
organ weights and organ / body weight ratios
other: Liver and kidney enzyme levels
Remarks on result:
other: Adverse effects were observed at all dose levels
Key result
Dose descriptor:
NOAEL
Effect level:
85 mg/kg bw/day (nominal)
Based on:
act. ingr.
Remarks:
(drinking water study)
Sex:
male/female
Basis for effect level:
clinical biochemistry
other: Liver and kidney enzyme levels
Remarks on result:
other: Based on significant decreases in the activities of glutamate-oxalate transaminase and lactate dehydrogenase in males and significant decrease in renal Na,K-ATPase in males and females at 145 mg/kg bw/day (0.2% drinking water).

Target system / organ toxicity

open allclose all
Key result
Critical effects observed:
yes
Lowest effective dose / conc.:
145 mg/kg bw/day (nominal)
System:
urinary
Organ:
kidney
Treatment related:
yes
Dose response relationship:
yes
Relevant for humans:
yes
Key result
Critical effects observed:
yes
Lowest effective dose / conc.:
145 mg/kg bw/day (nominal)
System:
hepatobiliary
Organ:
liver
Treatment related:
yes
Dose response relationship:
yes
Relevant for humans:
yes

Applicant's summary and conclusion

Conclusions:
Administration of LAS to Wistar JCL rats by test diets at dose levels of 0, 0.6 and 1.8% for 9 months (focusing on the liver and kidneys) revealed an LOAEL of 0.6% (300 mg/kg bw/day in diet), based on adverse effects at all dose levels.
Administration of LAS to Wistar JCL rats in drinking water at dose levels of 0, 0.07 and 0.2% for 9 months (focusing on the liver and kidneys) revealed an NOAEL of 0.07% (85 mg/kg bw/day in drinking water), based on significant decreases in the activities of glutamate-oxalate transaminase and lactate dehydrogenase in males and significant decrease in renal Na,K-ATPase in males and females at 145 mg/kg bw/day (0.2% drinking water).
Executive summary:

The 9 months sub-chronic oral toxicity study of LAS was performed in Wistar JCL rats, focusing on the liver and kidneys.

 

4 weeks old male and femaleWistar JCL rats(obtained from Shizuoka Agricultural Cooperative Association for Laboratory Animals) with body weight range100 - 124 g (males), 82 - 100 g (females)were used in the study. 5 animals were housed in each cage and maintained under controlled environmental conditions (temperature: Average of25 ± 1°C, humidity:50 - 60%, and 12 hours light /12 hours dark).CE-2diet (from CLEA Japan) and water were provided ad libitum.

 

The animals were administered daily with the LAS at following dose levels for 9 months:

 

Mixed in diet: 0, 0.6 and 1.8% (equivalent to 0, 300 and 900 mg/kg bw/day); 8 animals/sex/dose

 

Dissolved in drinking water: 0, 0.07 and 0.2 % (equivalent to 0,85 and 145mg/kg bw/day); 9 animals/sex/dose

 

Rats in 0.6 and 1.8% dose group of drinking water study exhibited severe weight loss so LAS administration was stopped after 2 weeks

 

Clinical observations, water consumption, food consumption and body weights were recorded weekly. At the end of study, blood was collected for estimation of haematological and clinical chemistry parameters.Gross findings were observed after euthanizing animals and organs were removed for organ weight measurements. Organ weights for brain, heart, lungs, liver, spleen, kidneys, adrenal gland, testes, uterus, and appendixwere recorded. Liver and kidney enzymes were also analysed. No histopathology was performed.

 

No mortality was observed throughout the study. Both female and male rats consuming LAS-containing water exhibited a slight redness at the tips of their facial fur, and coarse fur over their bodies. There was significant decrease in body weight gain in male and females of 1.8% dose group fed with diet and in males of 0.2% dose group consuming LAS contained water.Increased water consumption was observed in males of 1.8% dose group fed with diet and 0.2% dose group consuming LAS contained water.

 

A significant reduction in WBC was observed in 0.6% (diet) male rats compared to controls, and a significant reduction in MCV and MCH was observed in 1.8% (diet) female rats compared to controls. A marked reduction in cholesterol was observed in male and female rats of all dose groups [except female rats of 0.07% dose group (drinking water)] compared to controls. This indicate hepatocyte damage. GPT was significantly reduced in 0.6% dose group (diet) females, and reduced in females of other treatment groups. GOT was significantly reduced in 1.8% dose group (diet) males, and reduced in both females and males of other treatment groups. Albumin was significantly reduced in 1.8% (diet) males and reduced in males of 0.2% dose group (drinking water) and females of 1.8% dose group (diet). There was significant increase in ALP levels in male and female rats fed with 1.8% LAS-diet and cholinesterase levels in male rats fed with 1.8% LAS-diet.

 

In males of 1.8% (diet), the absolute liver and testes weight was significantly decreased and the relative testes and liver weight was significantly increased and both absolute and relative spleen weight were also significantly reduced. In females of 1.8% (diet), absolute and relative liver and caecum weight was significantly increased. There was also significant decrease in absolute and relative heart weight in females of 0.6% (diet) and 0.07% (drinking water) dose groups.

 

Liver enzymes were markedly reduced in 1.8% fed rats, due to impaired liver function, indicates reduced enzyme synthesis and direct enzyme inhibition by LAS or its metabolites. Renal G6Pase and Na, K-ATPase activity decreased, indicating kidney impairment.

 

Administration of LAS to Wistar JCL rats bytest diets at dose levels of 0, 0.6 and 1.8% for 9 months (focusing on the liver and kidneys) revealed an LOAEL of 0.6% (300 mg/kg bw/day in diet), based on adverse effects at all dose levels.

Administration of LAS to Wistar JCL rats in drinking water at dose levels of 0, 0.07 and 0.2% for 9 months (focusing on the liver and kidneys) revealed an NOAEL of 0.07% (85 mg/kg bw/day in drinking water), based onsignificant decreases in the activities of glutamate-oxalate transaminase and lactate dehydrogenase in males and significant decrease in renal Na,K-ATPase in males and females at 145 mg/kg bw/day (0.2% drinking water).