3,7,11,15-tetramethylhexadecane-1,2,3-triol

Repeated dose toxicity: oral

Administrative data

Endpoint:

short-term repeated dose toxicity: oral

Remarks:

combined with the reproduction/developmental toxicity screening test

Type of information:

experimental study

Adequacy of study:

key study

Study period:

October - December 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 422 (Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test)

Version / remarks:

July 2016

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: The United States Environmental Protection Agency (EPA) Health Effects Test Guidelines, OPPTS 870.3650, Combined Repeated Dose Toxicity Study with the Reproduction/Developmental Toxicity Screening Test

Version / remarks:

July 2000

Deviations:

no

Test guideline 3

Qualifier:

equivalent or similar to guideline

Guideline:

other: OECD Guidelines for Testing of Chemicals, Guideline 421, Reproduction/Developmental Toxicity Screening Test

Version / remarks:

July 2016

Deviations:

no

Test guideline 4

Qualifier:

equivalent or similar to guideline

Guideline:

other: The United States EPA Health Effects Test Guidelines, OPPTS 870.3550, Reproduction/Developmental Toxicity Screening Test

Version / remarks:

July 2000

Deviations:

no

Test guideline 5

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 407 (Repeated Dose 28-Day Oral Toxicity Study in Rodents)

Version / remarks:

October 2008

Deviations:

no

Test guideline 6

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method B.7 (Repeated Dose (28 Days) Toxicity (Oral))

Version / remarks:

May 2008

Deviations:

no

Test guideline 7

Qualifier:

equivalent or similar to guideline

Guideline:

other: The United States EPA Health Effects Test Guidelines, OPPTS 870.3050, Repeated dose 28-day oral toxicity study in rodents

Version / remarks:

July 2000

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

3,7,11,15-tetramethylhexadecane-1,2,3-triol

EC Number:

277-923-2

EC Name:

3,7,11,15-tetramethylhexadecane-1,2,3-triol

Cas Number:

74563-64-7

Molecular formula:

C20H42O3

IUPAC Name:

3,7,11,15-tetramethylhexadecane-1,2,3-triol

Test material form:

liquid: viscous

Details on test material:

- Physical appearance: colourless viscous liquid
- Storage conditions: at room temperature

Test animals

Species:

rat

Strain:

other: Crl:WI(Han) (outbred, SPF-Quality)

Details on species / strain selection:

Untreated, nulliparous, non-pregnant females and untreated males were used at the initiation of the study.

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Deutschland, Sulzfeld, Germany
- Females (if applicable) nulliparous and non-pregnant: yes
- Age at study initiation: Age at start pretest: Females: approximately 10-12 weeks; Age at start F0-treatment: Males approximately 10-12 weeks, Females approximately 12-14 weeks
- Weight at study initiation: males 249-280 g; females 191-231 g
- Fasting period before study: no
- Housing: pretest: Females were housed in groups of 5 females/cage in Macrolon plastic cages (MIV type, height 18 cm); Pre-mating: Animals were housed in groups of 5 animals/sex/cage in Macrolon plastic cages (MIV type, height 18 cm); Mating: Males and females were cohabitated on a 1:1 basis in Macrolon plastic cages (MIII type, height 18 cm); Post-mating: Males were housed in their home cage (Macrolon plastic cages, MIV type, height 18 cm) with a maximum of 5 animals/cage. Females were individually housed in Macrolon plastic cages (MIII type, height 18 cm); Lactation: Females were housed in Macrolon plastic cages (MIII type, height 18 cm). Pups were housed with the dam, except during locomotor activity monitoring of the dams, when the pups were kept warm in their home cage using bottles filled with warm water. In order to avoid hypothermia of pups, pups were not left without their dam or a bottle filled with warm water for longer than 30-40 minutes.
- Diet: Free access to pelleted rodent diet (SM R/M-Z from SSNIFF®
Spezialdiäten GmbH, Soest, Germany) (During motor activity measurements, animals did not have access to food for a maximum of 1.5 hours)
- Water: Free access to tap-water (During motor activity measurements, animals did not have access to water for a maximum of 1.5 hours)
- Acclimation period: Females: At least 5 days prior to start of treatment;
Males: Two days prior to start of treatment

DETAILS OF FOOD AND WATER QUALITY: Diet, water, bedding and cage-enrichment/nesting material evaluation for contaminants and/or nutrients was performed according to facility standard procedures. There were no findings that could interfere with the study.

ENVIRONMENTAL CONDITIONS (set to maintain)
- Temperature (°C): 18 to 24
- Humidity (%): 40 to 70
- Air changes (per hr): at least 10
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 28 October 2016 To: 23 December 2016

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

propylene glycol

Remarks:

specific gravity 1.036

Details on oral exposure:

- PREPARATION OF DOSING SOLUTIONS:
Formulations (w/w) were prepared daily within 6 hours prior to dosing and were homogenized to a visually acceptable level.
Adjustment was made for specific gravity of the vehicle. No correction was made for the purity/composition of the test item.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Analyses of samples of formulations taken on a single occasion during the treatment phase were analysed according to a validated method. The samples were analyzed for homogeneity (highest and lowest concentration) and accuracy of preparation (all concentrations). The accuracy of preparation was considered acceptable if the mean measured concentrations were 90-110% of the target concentration. Homogeneity was demonstrated if the coefficient of variation was ≤ 10%.
Stability of formulations over 6 hours at room temperature under normal laboratory light conditions (concentration range 1-200 mg/mL) was determined as part of the analytical method development and validation study.

Duration of treatment / exposure:

Males were treated for 30 days, i.e. 2 weeks prior to mating, during mating, and up to the day prior to scheduled necropsy.
Females that delivered were treated for 50-55 days, i.e. during 2 weeks prior to mating (with the objective of covering at least two complete estrous cycles), the variable time to conception, the duration of the pregnancy and at least 13 days after delivery up to and including the day before scheduled necropsy.
Females which failed to deliver healthy offspring were treated for 41-54 days.
Routinely, females that are littering are left undisturbed.The omission of one day of dosing over a period of several weeks was considered not to affect the toxicological evaluation.
Pups were not treated directly but were potentially exposed to the test item in utero, via maternal milk or from exposure to maternal urine/feces.

Frequency of treatment:

Once daily for 7 days per week

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

50 mg/kg bw/day (actual dose received)

Doses / concentrations 2

Dose / conc.:

150 mg/kg bw/day (actual dose received)

Doses / concentrations 3

Dose / conc.:

500 mg/kg bw/day (actual dose received)

No. of animals per sex per dose:

10

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale:
Based on the results of a 14-day dose range finding study the dose levels for this combined 28-day oral gavage study with reproduction/developmental
toxicity screening test were selected to be 50, 150 and 500 mg/kg bw/day. In this DRF increased liver weights only was observed at 500 mg/kg bw/day after 14 days of treatment and mortality occurred within 9 days after treatment at 1000 mg/kg bw/day.

Examinations

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: At least twice daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: At least once daily from start of treatment onwards up to the day prior to necropsy

BODY WEIGHT: Yes
- Time schedule for examinations: Males and females were weighed on the first day of treatment (prior to first dosing) and weekly thereafter. Mated females were weighed on Days 0, 4, 7, 11, 14, 17, 19 and 20 postcoitum and during lactation on PND 1, 4, 7 and 13.

FOOD CONSUMPTION:
- Weekly, except for males and females which were housed together for mating and for females without evidence of mating. Food consumption of mated females was measured on Days 0, 4, 7, 11, 14, 17 and 20 post-coitum and during lactation on PND 1, 4, 7 and 13

FOOD EFFICIENCY:
- Body weight gain in kg/food consumption in kg per unit time X 100 calculated as time-weighted averages from the consumption and body weight gain data: No

WATER CONSUMPTION: Yes
Subjective appraisal was maintained during the study, but no quantitative investigation was introduced as no treatment related effect was suspected.

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY: Yes
- Time schedule for collection of blood: F0 females 6h after dosing on Day 14 of treatment
- Anaesthetic used for blood collection: Yes (isoflurane)
- Animals fasted: Yes, o/n (with a maximum of 24h)
- How many animals: 5 F0/sex/group
- Parameters checked according to Guidelines

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: F0 females 6h after dosing on Day 14 of treatment
- Anaesthetic used for blood collection: Yes (isoflurane)
- Animals fasted: Yes, o/n (with a maximum of 24h)
- How many animals: 5 F0/sex/group
- Parameters checked according to Guidelines

URINALYSIS: No

NEUROBEHAVIOURAL EXAMINATION: Yes, FOB
- Time schedule for examinations: The selected males were tested during Week 4 of treatment and the selected females were tested once during the last week of lactation (e.g. PND 6-13). These tests were performed after observation for clinical signs (incl. arena observation, if applicable).
- Dose groups that were examined: 5 animals/sex/group
- Battery of functions tested: hearing ability, pupillar reflex and static righting reflex, fore- and hind-limb grip strength, locomotor activity.

IMMUNOLOGY: No

OTHER: reproduction and developmental parameters, plasma thyroid hormone analysis

Sacrifice and pathology:

GROSS PATHOLOGY: Yes, according to Guidelines

HISTOPATHOLOGY: Yes, according to Guoidelines

Other examinations:

organ weights according to Guidelines

Statistics:

The following statistical methods were used to analyse the data:
• If the variables could be assumed to follow a normal distribution, the Dunnett-test based on a pooled variance estimate was applied for the comparison of the treated groups and the control groups for each sex.
• The Steel-test was applied if the data could not be assumed to follow a normal distribution.
• The Fisher Exact-test was applied to frequency data.
• The Kruskal-Wallis nonparametric ANOVA test was applied to motor activity data to determine intergroup differences. In case intergroup differences were seen, the Wilcoxon test was applied to compare the treated groups to the control group.
All tests were two-sided and in all cases p < 0.05 was accepted as the lowest level of significance.

Results and discussion

Results of examinations

Clinical signs:

effects observed, non-treatment-related

Description (incidence and severity):

Pale faeces were temporary observed in two females at 500 mg/kg bw/day during the post coitum phase. A relation to treatment of this finding could not be ruled out. However, based on the incidence (in 2/10 females) and absence of other signs of ill health in these females, this finding was considered non-adverse and of no toxicological significance.
Salivation seen in a high incidence after dosing among animals of the 150 and 500 mg/kg bw/day dose groups for prolonged periods during treatment period was considered to be a physiological response rather than a sign of systemic toxicity considering the nature and minor severity of the effect and its time of occurrence (i.e. immediately after dosing). Salivation was also observed occasionally in animals of the control and the 50 mg/kg bw/day dose group.
Incidental findings that were noted included rales, piloerection, scabs (on various locations in the animals) and alopecia. These findings occurred within the range of background findings to be expected for rats of this age and strain which are housed and treated under the conditions in this study. At the incidence observed, these were considered not to be signs of toxicological relevance.

Mortality:

mortality observed, non-treatment-related

Description (incidence):

One male at 150 mg/kg bw/day died after blood sampling shortly before scheduled sacrifice. Its death was considered to be accidental and not related to treatment.
No further mortality occurred during the study period.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Statistically significant lower body weights and body weight gain were observed in males treated at 500 mg/kg bw/day on all occasions after start of treatment until sacrifice four weeks later. A 22% body weight gain was observed in these males of the treatment period, compared to 34% body weight gain in the controls. Body weights and body weight gain in the 50 and 150 mg/kg bw/day treated males remained in the same range as controls over the whole treatment period.
In females treated at 500 mg/kg bw/day, body weights and body weight gain were also lower until start of mating, two weeks after start of treatment, achieving levels of statistical significance for body weight gain on day 1 of mating in comparison with controls. During pregnancy any treatment related effect on maternal body weight and body weight gain was obscured by the increase in body weight due to their pregnancy. Nevertheless, lower body weights and body weight gain were observed during the post coitum phase in high dose females, achieving levels of statistical significance for body weights on day 17 and 20 post coitum, in comparison with controls. During lactation, statistically lower body weights were observed in the high dose dams from Day 1 until Day 13, in comparison with controls. Body weight gain, however, showed that their growth was normal and ran parallel to that of the other groups in the lactation phase.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

Lower food consumption was observed in males at 500 mg/kg bw/day over the first week of treatment (days 1-8 premating). During the continuation of treatment until sacrifice four week later, the food consumption before and after allowance for body weight of these high dose males was within the same range as of the other groups.
In females at 500 mg/kg bw/day, food consumption was (minimally) lower on all occasions from start of treatment until sacrifice at the end of lactation, achieving levels of statistical significance for absolute food consumption over days 0-4, 14-17 and 17-20 post coitum and days 4-7 and days 7-13 of lactation when compared to controls. Statistical significance was also reached for the relative food consumption in high dose females over days 7-13 of lactation.
Food consumption before or after allowance for body weight in males and females treated at 50 and 150 mg/kg bw/day was considered normal and in the similar range as the respective controls.

Food efficiency:

not examined

Water consumption and compound intake (if drinking water study):

not specified

Ophthalmological findings:

not examined

Haematological findings:

effects observed, non-treatment-related

Description (incidence and severity):

The haematological parameters of treated male and female rats were considered not to be affected after treatment up to 500 mg/kg bw/day.
The statistical significance for the mean red blood cell count in males at 500 mg/kg bw/day was considered to have occurred as a result of the relatively low control mean red blood cell count in comparison to the historical background data.
Any statistically significant changes for monocytes in low dose males and red blood cells and haematocrit in mid dose females were considered not to be toxicologically relevant as they occurred in the absence of a treatment-related distribution and remained within the range considered normal for rats of this age and strain.

Clinical biochemistry findings:

effects observed, treatment-related

Description (incidence and severity):

The following changes in clinical biochemistry parameters distinguished treated animals from control animals:
- Increases in the mean enzyme levels ALAT and ASAT were observed in male and female rats at 500 mg/kg bw/day, achieving levels of statistical significance for ALAT in both sexes and for ASAT in males when compared to controls.
- A statistically significant decrease in the mean level for total protein in males at 500 mg/kg bw/day. The total protein levels in females at 500 mg/kg bw/day were considered not to be affected by treatment. The lower mean value observed in these females was the result of a low protein level of 37.4 g/L (and concurrent low albumin level) in a single female which was considered to be a fortuitous finding and not representative of an effect in the group.
- A dose related increase in mean glucose level was observed in male rats at 150 and 500 mg/kg bw/day, not reaching statistical significance. The increase was minimal and considered non-adverse, since the glucose levels, even in the males at 500 mg/kg bw/day, were within (the high end of) the normal range for male rats of this age and strain.
The statistical significance for mean glucose levels in females at 150 and 500 mg/kg bw/day were the result of a relative low mean glucose level in controls. Since all glucose values remained within the range considered normal for female rats of this age and strain and in the absence of a treatment-related distribution, this finding was considered not to be toxicologically relevant.
No further toxicologically relevant changes occurred in clinical biochemistry parameters of treated male and female rats.

Urinalysis findings:

not examined

Behaviour (functional findings):

effects observed, non-treatment-related

Description (incidence and severity):

Hearing ability, pupillary reflex and static righting reflex were normal in all selected animals.
A tendency to a dose related increase in fore limb grip strength was observed in both sexes, not reaching levels of statistical significance. Since the grip strength values even in the high dose group at 500 mg/kg bw/day remained within normal limits for rats of this strain and age, this finding was considered to be non-adverse. The hind limb grip strength in the test item treated groups remained in the same range as controls.
For the motor activity, slightly higher mean values for total movements and ambulations were observed in high dose males at 500 mg/kg bw/day. These increases were the result of different habituation profile in these males, expressed by a higher activity of these males during the first part of the measurement (i.e. during the first five 5-minute intervals), in comparison with the habituation of the males in the other groups. The magnitude of change in habituation profile was minimal since the values of total movements and ambulations remained within normal limits for rats of this strain and age. Therefore this finding was considered to be nonadverse.
The variation in motor activity in test item treated females did not indicate a relation with treatment and remained in the same range as controls.

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

effects observed, non-treatment-related

Description (incidence and severity):

Increased mean relative liver weights were observed in males and females at 500 mg/kg bw/day, of approximately 9% when compared to controls, achieving a level of statistical significance in males only. Due to the low magnitude of increase, all liver weights remained well within normal limits for both sexes.
Mean weights of several other organs, either absolute weights or relative to body weight, in male and female rats at 500 mg/kg bw/day were (statistically significantly) different from controls. For these organs these differences were the result of the accompanying lower (terminal) body weight in these high dose animals in comparison with controls. The concerning changes included the absolute weights of the heart (both sexes) and the adrenals and seminal vesicles in males and uterus in females, and the relative weights of the brain (both sexes) and testes in males. The observed changes in these organs were considered not to be toxicologically relevant, also taking into account that no histopathological findings were observed in these organs.
Organ weights and organ to body weight ratios in animals treated at 50 and 150 mg/kg bw/day were similar to control levels.

Gross pathological findings:

effects observed, non-treatment-related

Description (incidence and severity):

Macroscopic observations at necropsy did not reveal any alterations that were considered to have arisen as a result of treatment.
The highest incidence of macroscopic findings in the stomach, although still within the normal limits, was observed in the high dose males at 500 mg/kg bw/day and included irregular surface of the forestomach and red discoloured foci in the glandular mucosa. These lesions were confirmed by histopathology as treatment related effects in this dose group.
The incidence of the other macroscopic findings among control and treated animals was also within the background range of findings that are encountered among rats of this age and strain. These were therefore considered not to be toxicologically relevant.

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

Test item-related microscopic findings after treatment with Phytantriol were noted in the stomach of the 500 mg/kg bw/day group males (minimal/slight hyperplasia of the squamous cells, and minimal/slight edema) and the liver of the 500 mg/kg/bw day females (minimal/slight hepatocellular hypertrophy).
In the kidneys, a minimally increased severity of hyaline droplet accumulation was present in all treated males compared to control animals. In the absence of a dose response and since these severities are within the normal background range, this was considered incidental and not test item-related.
The remainder of the recorded microscopic findings were within the range of background pathology encountered in rats of this age and strain. There was no test item-related alteration in the prevalence, severity, or histologic character of those incidental tissue alterations.

Histopathological findings: neoplastic:

no effects observed

Details on results:

In conclusion, treatment with Phytantriol by oral gavage in male and female Wistar Han rats at dose levels of 50, 150 and 500 mg/kg bw/day revealed parental toxicity at 500 mg/kg bw/day, expressed as reduced body weight gain and food consumption. Histopathological examination revealed squamous cell hyperplasia and edema in the stomach of males at 500 mg/kg/day, which were considered to represent non-adverse mild local
reaction to the test item. Furthermore, non-adverse increases in enzyme levels of ALAT and ASAT and liver weights (both sexes) and hepatocellular hypertrophy (females only) were observed.

Effect levels

Key result

Dose descriptor:

NOAEL

Effect level:

150 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

body weight and weight gain

food consumption and compound intake

Target system / organ toxicity

Critical effects observed:

no

Any other information on results incl. tables

Accuracy:

In the control group, no test item was detected.

The concentrations analysed in the formulations of low, md and high dose groups were between 96% and 98% (in agreement with target concentrations, i.e. mean accuracies between 90% and 110%).

Homogeneity:

The formulations in the low and high dose groups were homogeneous (i.e. coefficient of variation ≤ 10%), with coefficients of variation of 1.2% and 0.26% in the low and high dose, respectively.

Applicant's summary and conclusion

Conclusions:

Based on reduced body weight gain and reduced food consumption observed at 500 mg/kg bw/day, a NOAEL of 150 mg/kg bw/day is derived for parental toxicity.

Executive summary:

The test item, formulated in propylene glycol, was administered daily by oral gavage to SPFbred Wistar Han rats in a combined 28-day repeated dose toxicity study with the reproduction/developmental toxicity screening test. One control group and three treated groups were tested (50, 150, 500 mg/kg bw/day), each consisting of 10 males and 10 females. Males were treated for 30 days, i.e. 2 weeks prior to mating, during mating, and up to termination. Females were treated for 50-55 days, i.e. during 2 weeks prior to mating, during mating, during post-coitum, and during 13-15 days of lactation. Females which failed to deliver healthy offspring were treated for 41-54 days.

The following observations and examinations were evaluated: mortality / viability, clinical signs (daily), functional observations and locomotor activity (end of treatment), body weight and food consumption (at least at weekly intervals), estrous cycle determination (14 days prior to treatment, 14 days of treatment and during mating until evidence of mating, and the day of necropsy), clinical pathology (end of treatment), measurement of thyroid hormone T4 (F0-males at the end of treatment, PND 13-15 pups), macroscopy at termination, organ weights and histopathology on a selection of tissues. In addition, the following reproduction/developmental parameters were determined: mating, fertility, precoital time,

number of implantation sites, gestation index and duration, parturition, maternal care, sex ratio and early postnatal pup development (mortality, clinical signs, body weights, sex, anogenital distance, areola/nipple retention and macroscopy). Blood was sampled for exposure control evaluation (from first 5 F0-males and all F0-females/sex/group at day 14 of treatment and from PND 13-15 pups from litters of the selected 5 F0-females). Accuracy and homogeneity of formulations were demonstrated by analyses.

Parental results:

After treatment at 500 mg/kg bw/day, a minimal increase in fore limb grip strength was observed in both sexes and a slightly different habituation profile in males only, as expressed by a higher number of movements and ambulations during the first part of motor activity testing. Due to the low magnitude of the changes in grip strength and motor activity, the results were still within the normal limits for these parameters in rats of this age and strain. Therefore, these findings at the dose level of 500 mg/kg bw/day were considered to be non-adverse.

Treatment-related changes at 500 mg/kg bw/day were observed as statistically significant lower body weights and food consumption, changes in several clinical biochemistry parameters, including increases in ALAT and ASAT, and glucose and a decrease in total protein. The changes in glucose and total protein were considered to be non-adverse, based on the low magnitude of change. Minimal increases in liver weights were observed in these high dose animals, still remaining within normal limits. In addition, a low severity of hepatocellular hypertrophy was recorded in the females at 500 mg/kg bw/day, which was considered to be a non-adverse finding in the absence of any degenerative findings in the liver of these animals. Whereas the increases in the enzyme levels ALAT and ASAT and liver weights were slightly more pronounced in males than in females, the hepatocellular hypertrophy was only seen in females. Although the increased enzyme levels might be indicative of liver damage, this was not confirmed by histopathology in the males. Therefore, also the changes in enzyme levels and liver weight were considered to be non-adverse.

Histopathological examination revealed squamous cell hyperplasia and edema in the stomach of males at 500 mg/kg bw/day, which were considered to represent non-adverse mild local reaction to the test item. No treatment-related changes were noted after treatment at 500 mg/kg bw/day in the other parental parameters investigated in this study (i.e. clinical appearance, haematology investigations, sperm staging (in males) and estrous cycle (in females)). Any changes in the various study parameters after treatment at 50 and 150 mg/kg bw/day were considered no signs of treatment related parental toxicity.

In conclusion, treatment with Phytantriol by oral gavage in male and female Wistar Han rats at dose levels of 50, 150 and 500 mg/kg bw/day revealed parental toxicity at 500 mg/kg bw/day, expressed as reduced body weight gain and food consumption. Furthermore, non-adverse increases in enzyme levels of ALAT and ASAT and liver weights (both sexes), hepatocellular hypertrophy (females only) and mild local reaction in the stomach to the test item in males (squamous cell hyperplasia and edema) were observed. Based on these results, a NOAEL parental toxicity of 150 mg/kg bw/day is derived.