2-heptylcyclopentanone

Repeated dose toxicity: oral

Administrative data

Endpoint:

repeated dose toxicity: oral

Remarks:

other: reproduction and developmental screening

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Oct 2011 - Mar 2012

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:

2012

Report date:

2012

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:

March 1996

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: • Methods of Testing New Chemical Substances (PFSB Notification No. 0331-7 on March 31, 2011; MIB Notification No. 5 on March 29, 2011; EPPB Notification No. 110331009)

Version / remarks:

March 2011

Deviations:

no

Principles of method if other than guideline:

An additional group of 10/sex was not mated in the control and 800 mg/kg bw/day groups Of these after completing the 42-day repeat dose administration, 5 cases each of the males and non-mating females in the control and 800 mg/kg bw/day groups were assigned to the recovery-study group to examine recovery from the toxicities through 14 days of drug administration.

GLP compliance:

yes

Limit test:

no

Test material

Test material information

1

Reference substance name:

2-heptylcyclopentanone

EC Number:

205-273-1

EC Name:

2-heptylcyclopentanone

Cas Number:

137-03-1

Molecular formula:

C12H22O

IUPAC Name:

2-heptylcyclopentan-1-one

Test material form:

liquid

Test animals

Species:

rat

Strain:

other: Crl:CD(SD)[SPF]

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Atsugi Breeding Center of Charles River Laboratories Japan, Inc.,
- Females (if applicable) nulliparous and non-pregnant: yes
- Age at study initiation: 10 weeks old
- Weight at study initiation: males: 323 to 381 g; females: 204 to 248 g
- Fasting period before study: no
- Housing: The animals were placed individually in rearing cages covered in the front and bottom with stainless nets and reared with washable rearing machines. However, successfully mated female animals were reared from Day 18 of gestation to Day 4 of nursing period in Ekonkeji with nesting materials.
- Diet: The animals were fed freely with radiation-sterilized solid feeds (CRF-1, lot no.: 110106, Oriental Yeast).
- Water: Tap-water (Iwata City Waterworks) was taken freely as the drinking water by the animals through automatic water nozzles or the water bottles.
- Acclimation period: 8 days (after a 5 day quarantine period)

DETAILS OF FOOD AND WATER QUALITY: Analysis of contaminations in the feeds was conducted by Eurofin Scientific, verifying that they were within the acceptable range drafted by Japan Experimental Animal Feed Association, and the analysis results were retained by BSRC.
Inspection of water quality of the tap water based on Water Supply Act was conducted in October 2011 by EcoPro Research Company Limited, and it was verified that the analysis results meet the water quality standards for drinking water (MHLW Ordinance No. 101 on May 30, 2003). Moreover, bacteriological tests (general bacteria and coliform tests) were conducted by BSRC in November and December 2011 and January 2012, verifying that bacteria are not detected in the water. The test results (certificate of water quality test: No. 113689-3, bacterial tests: No. GT11-11, GT11-12, and GT12-01) were retained by BSRC.
Contaminations that could have affected the study were not present in the nesting materials, feeds, and water used. Therefore, there were no changes in environmental factors with any potential impacts on the reliability of the data during the rearing period.


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22.8 to 24.4
- Humidity (%): 41.0 to 60.5
- Air changes (per hr): at least 12
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 1 November 2011 To: 27 December 2011

Administration / exposure

Route of administration:

oral: gavage

Details on route of administration:

The volume of administration, 0.5 mL per 100 g of body weight was adopted, and the amounts of solutions to be administered to the males and females during the pre-mating and mating periods and during the administration period after the end of mating period were calculated based on the most recent, individually measured body weights. Furthermore, the amounts of solutions to be administered to the females during the gestation period and after delivery were calculated based on individual body weights measured on Days 0 (mating confirmation date), 7, 14, and 20 and the date of delivery completion (Day 0 of nursing period). Solutions were administered once a day, collected while being stirred with a magnetic stirrer.

Vehicle:

corn oil

Details on oral exposure:

- Method of formulation:
Administration solutions of 10, 40, and 160 mg/mL doses were prepared by mixing the investigational substance thoroughly in corn oil (preparation examples, 50 mg/kg bw/day group: dilute 5.0 g of the investigational substance with corn oil to create 500 mL solution using a measuring cylinder; 200 mg/kg bw/day group: dilute 20.0 g of the investigational substance with corn oil to create 500 mL solution using a measuring cylinder; 800 mg/kg bw/day group: dilute 80.0 g of the investigational substance with corn oil to create 500 mL solution using a measuring cylinder).

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Analysis of the administration solutions were performed based on the analytical methods established by the “Validation of 2-Heptan-1-ylcyclopentan-1-one Concentration Measurement Methods and the Examination of its Stability in the Medium [Study No.: D642 ( 314–051 )]”. The stability of the investigational substance was verified by measuring its concentration in the samples obtained from 10 and 160 mg/mL administration solutions that were stored in low temperatures for 8 days right after preparation and then left for 1 more day at room temperature. As a result, it was verified that the investigational substance is stable since the ratio of concentration of the substance right after preparation to mean concentration (retention rate) meets the criteria (90.0 to 110.0%) with relative standard deviation of 5.0% or less. Therefore, administration solutions were stored under light-shielded conditions in low temperatures and used within 8 days of preparation. Incidentally, storage temperatures inside the storage location of the administration solutions (prefabricated low-temperature storage ch. 66, allowable range: 1 to 9˚C) ranged from 2.5 to 7.2˚C.
Analysis of concentration / homogeneity was performed to all administration solutions at the time of the first and last preparation. According to the result, all of the administration solutions met the criteria for concentration / homogeneity compared to the configured concentration (10, 40, and 160 mg/mL) (ratio to configured concentration: 90.0 to 110.0%, relative standard deviation: 5.0% or less), and the investigational substance was not detected in the solution administered to the control group. Therefore, the administration solutions were verified to have been prepared properly.

Duration of treatment / exposure:

Duration of administration to males was 42 consecutive days, including 14 days before mating, 14 days of mating period, and 14 days after the end of mating period. Duration of administration to the females in the mating group was 14 days before mating, the mating period (maximum of 11 days until successful mating), and from the gestation period to Day 4 of nursing period (with delivery completion date as Day 0) for females with confirmed mating (42 to 52 days). Administration to the females that did not deliver after mating confirmation was continued until the day before the autopsy on Day 25 of gestation (Day 24 of gestation). Duration of administration to the females in the non-mating group was consecutive 42 days.
Administration to the males and females in the recovery testing groups was suspended for 14 days from the day after the final administration (Day 0 of recovery)

Frequency of treatment:

daily

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

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

Doses / concentrations 2

Dose / conc.:

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

Doses / concentrations 3

Dose / conc.:

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

No. of animals per sex per dose:

12/sex in mating groups
10/sex in non-mating groups (control and 800 mg/kg bw/day); 5 of the latter in the recovery groups.

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: In the single-dose study of 2-Heptan-1-ylcyclopentan-1-one [study no.: D643 ( 314–052 )], there were no deaths of animals from administration of 2,000 mg/kg bw. Furthermore, a preliminary 2-week administration study [study no.: D646 ( 314–055 )] was conducted with 60, 200, 600, and 1,000 mg/kg bw/day dose levels. According the results, there were no deaths of male or female animals, and no changes attributed to administration of the investigational substance were observed in the general conditions, body weight, amount of feed intake, hematological tests, and autopsy findings. In urinalysis, squamous cell positive (1+ to 2+) was observed in 3 out of 6 cases of males in the 1,000 mg/kg bw/day group. In blood coagulation test, prolongation of the activated partial thromboplastin time was observed in the males in 600 and 1,000 mg/kg bw/day groups. In blood biochemistry test, high values of total cholesterol and phospholipids in the males and females in 600 and 1,000 mg/kg bw/day groups and high values of γ-GTP in the males and females in the 1,000 mg/kg bw/day group were observed. Furthermore, the males in the 1,000 mg/kg bw/day group exhibited low values of neutral fat. According to the measurement of organ weights at autopsies, high liver weight values were observed in the males and females in 600 and 1,000 mg/kg bw/day groups. Moreover, high kidney weight values were observed in the males in 600 and 1,000 mg/kg bw/day groups.
Duration of administration in the main study was extended from the duration in the preliminary study, and the main study included pregnant females as subjects of administration. However, 800 mg/kg bw/day was adopted as the dose for the high-dosage group given that the changes observed in the preliminary study were minor. Doses for lower-dosage groups were set at 200 and 50 mg/kg/day through divisions by a common ratio of 4.

Positive control:

No.

Examinations

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS:
- Time schedule: 3 times daily, once a day during the recovery period.

DETAILED CLINICAL OBSERVATIONS:
- Time schedule: included in FOB

BODY WEIGHT:
- Time schedule for examinations: Body weights of males and the females in the non-mating groups were measured on Days 0 (date of the start of administration), 7, 14, 21, 28, 35, 41, and 42 (date of autopsy or Day 0 of recovery) of administration, and the amount of increase in body weight from Day 0 to 41 was calculated. Body weights of the males and females in the recovery testing groups measured after the end of administration period and on Days 0, 7, 13, and 14 (autopsy day) of recovery, and the increase in body weight from Day 0 to 13 of recovery was calculated.
Body weights of the females in the mating groups were measured on Days 0 (date of the start of administration), 7, and 14 of administration, and the increase in body weight from Day 0 to 14 of administration was calculated. Furthermore, body weights of females that mated were measured on Days 0, 7, 14, and 20 of gestation as well as on Days 0, 4, and 5 (autopsy day) of nursing period after delivery, and the increase in body weight during each period, from Day 0 to 20 of gestation and from Day 0 to 4 of nursing period, was calculated. Body weights of females whose offspring all died were measured also at the time of the discovery of offspring deaths. Body weights of females without any natural deliveries were measured also on autopsy day on Day 25 of gestation.

FOOD CONSUMPTION:
- Feed weights for males and the females in the non-mating groups were measured on Days 0 (date of the start of administration), 7, 14, 21, 28, 35, and 41 (day before autopsy) of administration to find the feed intake from one measurement day to the next, and the mean daily feed intake was calculated. Furthermore, the cumulative feed intake between Day 0 and 14 and between Day 21 and 41 of administration for males and between Day 0 and 41 of administration for the females in the non-mating group was calculated. Feed weights for the males and females in the recovery testing groups were measured after the end of administration period, on Days 0, 7, and 13 (day before autopsy) of recovery to find the feed intake from one measurement day to the next, and the mean daily feed intake and the cumulative feed intake from Day 0 to 13 of recovery were calculated.
Feed weights given for the females in the mating groups were measured on Days 0 (date of the start of administration), 7, and 14 of administration to find the feed intake from one measurement day to the next, and the mean daily feed intake and the cumulative feed intake from Day 0 to Day 14 of administration were calculated. In addition, feed weights for mated females were measured on Days 0, 7, 14, 18 and 20 of gestation and Days 0 and 4 of nursing period after delivery to find the feed intake from one measurement day to the next, and the mean daily feed intake and the cumulative feed intake from Day 0 to 20 of gestation were calculated.

FOOD EFFICIENCY: no

WATER CONSUMPTION : No.

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY:
- Time schedule for collection of blood: at necropsy
- Anaesthetic used for blood collection: no information
- Animals fasted: No.
- How many animals: 5 mated and 5 non-mated/sex/group
- Parameters checked were: According to test guidelines

CLINICAL CHEMISTRY: Yes, at necropsy
- Anaesthetic used for blood collection: no information
- Animals fasted: No.
- How many animals: 5 mated and 5 non-mated/sex/group
- Parameters checked were: According to test guidelines

URINALYSIS: Yes, 5/sex/group (non-mating groups) at the end of the administration period and at the end of the recovery period (pH, occult blood, ketone bodies, glucose, protein, bilirubin, and urobilinogen, amounts of urine and color tones, urine electrolyte concentration (sodium, potassium, and chloride), osmotic pressure, microscopic examinations were conducted using the sediments (erythrocytes, leukocytes, squamous cells, transitional epithelial cells, renal tubular epithelial cells, casts, fat globules, mucous threads, and crystals were investigated)

NEUROBEHAVIOURAL EXAMINATION: Yes, FOB
(detailed observation of symptoms, pupillary reflex, approaching reaction, tactile response, auditory response, grip strengths of the fore and hind limbs, locomotor activity)
The FOB was performed on all surviving animals. Of the observation items, detailed observation of symptoms was conducted once before grouping and once every week during administration and recovery periods, except for mated females and females that delivered offspring, to whom observations were conducted on Days 7 and 14 and on Day 4 of nursing period, respectively.
Observation of kinesthetic response to various stimuli and measurement of grip strength and locomotor activity were performed on 5 animals from each group, on Day 41 of administration to males and the females in the non-mating group and on Day 4 of nursing period to post-delivery females (in the order of the dates of delivery completion. The same were performed on the males and females in the recovery testing group on Day 41 of administration and Day 13 of recovery.
Detailed observation of symptoms was performed on all animals before grouping. Observations during the administration period were started at 30 minutes after administration.

Sacrifice and pathology:

GROSS PATHOLOGY:
- According to test guidelines

ORGAN WEIGHTS
- Epididymides, Kidneys, Liver and Testes.

HISTOPATHOLOGY:
- According to test guidelines; liver and kidneys of all groups were examined.

Statistics:

The following statistical methods were used to analyse the data:
Bartlett’s test for equal variance was first performed. In the case of equal variance, statistical significance between the control and each administration group were tested using Dunnet’s multiple comparison test. In the case of unequal variance based on Bartlett’s test, statistical significance between the control and each administration group was tested using Steel’s test.
For birthrate, mating rate, and conception rate, x2 test was adopted.
The rate of incidence of abnormal sexual cycles, test items in detailed observation of symptoms and observation of kinaesthetic response to various stimuli other than standing, defecation, and urination, sex ratio per group, and rate of incidence of histopathological findings were tested using Fisher’s exact test.

Bartlett’s test for equal variance was conducted with 5% level of significance, and the other tests were conducted with two-tailed significance levels at 5% and 1%.

Results and discussion

Results of examinations

Clinical signs:

effects observed, non-treatment-related

Description (incidence and severity):

Sialorrhea (excessive salivation) was sporadically observed, in 5/12, 4/12, and 3/10 cases from the males in the 800 mg/kg bw/day group, females in the mating groups, and females in the non-mating groups, respectively. In addition, no changes in the general conditions were observed in either males or females during the recovery period. Moreover, unclean fur coat condition (around the anus / reproductive organ) was observed during the nursing period in a female in the 800 mg/kg bw/day, whose offspring all died.
There were no abnormal findings in in-cage observation items (observed lower or higher numbers of some postures were judged to be casual due to the lack of similar behaviors on other observation dates). In observations outside the cage, mild sialorrhea was observed in 3 to 5 cases in the 800 mg/kg bw/day group since Day 16 of administration, with significantly high number of occurrences exhibited on Day 41. Although 1 case of mild sialorrhea was also observed in the 200 mg/kg bw/day on Day 23 of administration, this was judged to be a casual change given the frequency of its occurrence. There was no difference in the number of occurrences of other findings noted during observations outside the cage between the control and the groups treated with the investigational substance. In the open-field observations, the number of times the animals stood with support was significantly low before grouping in animals later assigned to the 50 mg/kg bw/day group. However, this change occurred before administration, and it was not related to administration of the investigational substance. In addition, the same group exhibited significantly low frequency of defecation on Day 41 of administration, although this was not judged to be the effect of administration of the investigational substance since this change was not observed on other measurement dates and did not relate to the dosage. There was no significant difference in the number of occurrences of other findings during the open-field observations between the control and the groups treated with the investigational substance.
In the females in the non-mating groups, there was no difference in the number of occurrences of in-cage observation items between the control and the 800 mg/kg bw/day groups. In observations outside the cage, the 800 mg/kg bw/day group exhibited significantly high frequency of “extremely easy” and significantly low frequency of “easy” as the ease of extracting the animal from the cage on Day 24 of administration, although this was not related to administration of the investigational drug since the frequency of either evaluation was similar on other observation dates. Moreover, mild sialorrhea was observed in 1 to 4 cases in the 800 mg/kg bw/day group since Day 8 of administration. There was no significant difference between the control and the 800 mg/kg bw/day group in the number of occurrences of other findings noted in observations outside the cage. In open-field observations, the frequency of standing with support was significantly high in the 800 mg/kg bw/day group on Day 8 of administration, though this was not judged to be the effect of administration of the investigational substance as this change was not observed on other measurement dates. There was no significant difference between the control and the 800 mg/kg bw/day group in the number of occurrence of other findings noted in open-field observations. There were no abnormal findings in any of the observation items in observations conducted during the recovery period.
In the females in the mating groups, the number of occurrences of “sitting by lowering the hip” was significantly high and the number of occurrences of “standing and sitting while paying attention to the observer” was significantly low in the 50 mg/kg bw/day group on Day 4 of nursing period, though these changes were judged to be casual due to the lack of similar behaviors on other observation dates. There was no significant difference between the control and the groups treated with the investigational substance in the number of occurrences of other findings noted in in-cage observations. In observations outside the cage, mild sialorrhea was observed in 1 to 4 cases in the 800 mg/kg bw/day group since Day 8 of administration, and the number of occurrences on Day 4 of nursing period was significantly high. Incidentally, 1 case in the 800 mg/kg bw/day group exhibited severe sialorrhea on Day 14 of gestation. There was no significant difference between the control and the groups treated with the investigational substance in the number of occurrences of other findings noted in observations outside the cage. There was no significant difference between the control and the groups treated with the investigational substance in the number of occurrences of findings noted in open-field observations

Mortality:

no mortality observed

Description (incidence):

No deaths or moribund conditions were observed in either male or female animals throughout the study period.

Body weight and weight changes:

effects observed, non-treatment-related

Description (incidence and severity):

No statistically significant differences between the control and the groups treated with the investigational substance were found in males and the females in the non-mating groups on any of the measurement dates during administration and recovery periods.
Although the body weight increase value higher than the control group observed in the females in the 50 mg/kg bw/day mating group during the gestation period was statistically significant, no statistically significant differences between the control group and the 200 and 800 mg/kg bw/day groups were found.

Food consumption and compound intake (if feeding study):

effects observed, non-treatment-related

Description (incidence and severity):

In males, no statistically significant differences in feed intake on measurement dates during the administration period or in the cumulative feed intake between the control and the groups treated with the investigational drugs were found. During the recovery period, the mean daily intake from Day 0 to 7 of recovery was significantly higher in the 800 mg/kg bw/day group. However, this change was judged to be a casual occurrence since the difference was small and no difference in the cumulative feed intake was observed during the recovery period.
In the females in the non-mating groups, no statistically significant differences in feed intake on measurement dates during the administration period or in the cumulative food intake between the control and the 800 mg/kg bw/day groups were found. During the recovery period, the mean daily intake from Day 7 to 13 of recovery was significantly higher in the 800 mg/kg group. However, this change was judged to be a casual occurrence since the difference was small and no difference in the cumulative feed intake was observed during the recovery period.
In the females in the mating groups, the mean daily feed intake on Day 0 to 7 and Day 7 to 14 of gestation and Day 0 to 4 of nursing period was significantly high in the 50 mg/kg bw/day group, with also significantly high cumulative feed intake during the gestation period. No significant differences were found between the control and the 200 and 800 mg/kg bw/day groups.

Food efficiency:

not examined

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

not examined

Ophthalmological findings:

not examined

Haematological findings:

effects observed, non-treatment-related

Description (incidence and severity):

In males, although the platelet count in the 800 mg/kg bw/day group was significantly higher than the control group at the end of administration period, this change was minor and was not judged to be the effect of administration of the investigational substance. At the end of recovery period, there was no statistically significant difference in any of the test items between the control and the groups treated with the investigational substance.
In the females in the non-mating groups, there was no statistically significant difference in any of the test items between the control and the 800 mg/kg bw/day administration group at the end of administration period. Although the ratio of eosinophils was significantly lower in the 800 mg/kg bw/day group than the control group at the end of recovery period, this change was minor and judged to be a casual occurrence.
In the females in the mating group, there was no statistically significant difference in any of the test items between the control and the groups treated with the investigational substance.
No statistically significant differences were found between the control and the groups treated with the investigational substance in males and females or in females in the mating groups at the end of administration period and at the end of recovery period.

Clinical biochemistry findings:

effects observed, treatment-related

Description (incidence and severity):

In males, the total protein, phospholipids, total bilirubin, and γ-GTP were significantly higher in the 800 mg/kg bw/day group than the control group at the end of administration period. At the end of recovery period, there was no statistically significant difference in any of the test items between the control and the groups treated with the investigational substance.
In the females in the non-mating groups, blood glucose, BUN, total bilirubin, and sodium were significantly lower in the 800 mg/kg bw/day group than the control group at the end of administration period. At the end of recovery period, ALP was significantly lower in the 800 mg/kg bw/day group than the control group.
In the females in the mating groups, phospholipids, total cholesterol, and γ-GTP were significantly higher in the 800 mg/kg bw/day group than the control group.
In males, α2-globulin concentration was significantly higher and γ-globulin ratio and concentration significantly lower in the 800 mg/kg bw/day group than the control group at the end of administration period. At the end of recovery period, α1-globulin concentration was significantly higher in the 800 mg/kg bw/day group than the control group.
In the females in the non-mating groups, there was no statistically significant difference in any of the test items between the control and the groups treated with the investigational substance at the end of administration period and at the end of recovery period.
In the females in the mating groups, α1-globulin concentration was significantly higher in the 800 mg/kg bw/day group. In addition, the albumin ratio was significantly low in the 200 mg/kg bw/day group, though this change was casual with no relations to the dose.

Urinalysis findings:

effects observed, treatment-related

Description (incidence and severity):

In males, the 800 mg/kg bw/day group exhibited a tendency of high urine volumes on the week of the end of administration compared to the control group. Furthermore, in urinary sediment tests, renal tubular epithelial cells (1+) was found 3/5 cases and 3/5 cases in the 200 and 800 mg/kg bw/day groups, respectively, and renal tubular epithelial cells (2+) was found in 2/5 cases in the 800 mg/kg bw/day group. At the end of recovery period, the concentration and total discharge volume of urine chloride were significantly lower in the 800 mg/kg bw/day group than the control group.
In the females in the non-mating groups, urine volumes were significantly higher and the urine osmotic pressure and urine sodium, urine potassium, and urine chloride concentrations were significantly lower in the 800 mg/kg bw/day group than the control on the week of the end of administration. Furthermore, in urinary sediment tests, renal tubular epithelial cells (+1) was observed in 2/5 cases in the 800 mg/kg bw/day group. At the end of recovery period, the total urine sodium discharge volume was significantly higher in the 800 mg/kg bw/daygroup than the control group
These effects were considered treatment related but not adverse as these are all related to intensive metabolising the substance not with toxicity.

Behaviour (functional findings):

effects observed, non-treatment-related

Description (incidence and severity):

In the observations of kinaesthetic response to various stimuli, there were no changes attributed to administration of the investigational substance in either males or females.
No statistically significant differences in the fore-limb and hind-limb grip strengths were found between the control and the groups treated with the investigational substance in males and females or in females in the mating groups at the end of administration period and at the end of recovery period.
In males, the amount of activity from 50 to 60 minutes after the start of measurement at the end of administration period was statistically low and the measured values from 30 to 40 minutes after the start of measurement at the end of recovery period was statistically high in the 800 mg/kg bw/day group compared to the control. However, these changes were not judged to be related to administration of the investigational substance, since no effects related to acceleration or suppression of activity were found during the observations of general conditions or the detailed observations of symptoms.
In the females in the non-mating groups and the females in the mating groups, there was no difference between the control and the groups treated with the investigational substance in the amount of locomotor activity at the end of administration period and the end of recovery period.

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

In males, the relative liver weights in the 200 mg/kg bw/day group and the absolute and relative liver weights and the relative kidney weights in the 800 g/kg bw/day group were significantly higher than the control at the end of administration period. There was no significant difference between the control and the 800 mg/kg group at the end of recovery period.
In the females in the non-mating groups, the absolute and relative liver weights and the relative kidney weights were significantly high in the 800 mg/kg bw/day group at the end of administration period. The absolute heart weights were significantly low and the relative pituitary gland and liver weights were significantly high in the 800 mg/kg group at the end of recovery period, though these changes were minor.
In the females in the mating group, the absolute and relative liver, kidney, and ovary weights were significantly high in the 800 mg/kg bw/day group.

Gross pathological findings:

effects observed, non-treatment-related

Description (incidence and severity):

In males, brown spots and cysts in the lungs, gastric nodules, diverticula of small intestine, liver deformation, accentuated lobular patterns, red spots and white spots, renal scarring, epididymal nodules, prostatic hyperplasia, and cerebral ventriculomegaly were found at the end of administration period. At the end of recovery period, black spots and brown spots in the lungs, white spots in the liver, renal cysts and scarring, and cerebral ventriculomegaly were found.
In the females in the non-mating groups, black spots in the stomach, accentuated lobular patterns and red spots in the liver, renal cysts and scarring, and white spots in the adrenal glands were found at the end of administration period. At the end of recovery period, hepatodiaphragmatic nodules and renal scarring were found.
In the females in the mating groups, gastric nodules and white spots, diverticula of small intestine, brown spots and white spots in the liver, ascites, renal cysts and scarring, ovarian cysts, fallopian cysts, and vaginal nodules were found.
Any of these findings were either found in the control group as well or occurred as singular instances, and were not related to administration of the investigational substance.
In addition, 2 cases of females that did not deliver offspring in the 200 mg/kg bw/day were both found to have enlarged vaginal cavity. The dam in the 800 mg/kg bw/day group whose offspring all died was found to have thymus atrophy, dilated proventricular cavity, and enlarged and pale kidneys, and it was emaciated. There were no abnormal findings in the male and female that failed gestation in the 50 mg/kg bw/day group.

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

As findings that were potentially related to administration of the substance, hepatocellular hypertrophy in the liver was observed in 4/7 cases of males in the 800 mg/kg bw/daygroup at the end of administration period. Moreover, renal hyaline / eosinophilic globules were found as mild symptoms in 6/7, 10/11, 11/12, and 2/7 cases and as moderate symptoms in 0/7, 0/11, 1/12, and 5/7 cases in the control, 50, 200, and 800 mg/kg bw/day groups, respectively, and a statistically significant dose-dependent aggravation of the degrees of symptoms was found. These renal hyaline globules were considere to be due to alpha-hydrocarbone nepropathy based on the measured alpha-2u globulins measured.
There were no findings potentially related administration of the substance in the females in the mating and non-mating groups and the female that failed gestation in the 50 mg/kg bw/day group.
In the female that did not deliver offspring in the 200 mg/kg bw/day group, endometrial hyperplasia and goblet cell metaplasia in vaginal epithelium were found.
In the dam whose offspring all died in the 800 mg/kg bw/day group, thymus atrophy, necrosis of duodenal villi, basophilic tubules, acidophilic changes, and vacuolation of the kidneys, bladder edema, and intraperitoneal hyperpigmentation of the Harderian gland were found.
All the other findings observed in the males and females at the end of administration period and at the end of recovery period were believed to be naturally occurring changes given the number of occurrences and severity of the conditions.
Overall this means that treatment-related effects were seen but not considered adverse.

Histopathological findings: neoplastic:

no effects observed

Other effects:

no effects observed

Details on results:

The effects seen on liver are considered substance related, as the substance is a fatty acid chain which will be metabolised in the liver. The observed activation of the liver is considered an adaptive effect related to the increase in fatty acid burden in general and not specifically to this substance and therefore considered to be not adverse in nature.
The effects observed in the renal tubular cells of high dose males are not accompanied by other effects on the kidney and is likely associated with alpha hydrocarbon nephropathy. The observed increase in urinary volume did not show a dose relationship, and did not show a statistical significant increase in the high dose group. As alpha hydrocarbon nephropathy is specific for male rats and not relevant for human risk assessment, this observation will not be considered for the NOAEL. In summary, the observed minor effects on liver and kidneys are considered either adaptive, not related to any dysfunction of these organs or species specific. Therefore it is concuded that no adverse effects were observed up to and including 800 mg/kg bw/day, the highest dose tested.

Effect levels

Key result

Dose descriptor:

NOAEL

Effect level:

>= 800 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male/female

Remarks on result:

not determinable due to absence of adverse toxic effects

Target system / organ toxicity

Key result

Critical effects observed:

no

Applicant's summary and conclusion

Conclusions:

In conclusion, treatment with the substance, dosed via oral gavage at dose levels 50, 200 or 800 mg/kg bw/day resulted in a NOAEL for males and females of 800 mg/kg bw/day based on absence of adverse effects at 800 mg/kg bw/day, the highest dose tested.

Executive summary:

The present summary includes the effects on reproductive toxicity (fertility and developmental toxicity)

Introduction and methods: For Fleuramone a combined repeated dose toxicity study with the reproductive/developmental screening test according to OECD TG 422 was performed with rat, with dose groups 0, 50, 200 and 800 mg/kg bw/day. The control and 800 mg/kg bw/day groups also included non-mating and recovery groups. The following repeated dose toxicity parameters were recorded: mortality, clinical signs body weight and food consumption, haematology parameters and organ weights of liver, kidney, testis and epididymides. These organs were also microscopically evaluated. The parameters assessed for fertility and developmental toxicity are described at the respective sections. The doses were confirmed by analytics.

Results: Clinically: No deaths or moribund conditions were observed in either male or female animals, and there were no effects of administration of the investigational substance on body weight, amount of food intake, haematological tests, and blood coagulation tests. In terms of detailed observations based on observations of general conditions and FOB, sialorrhea (excessive salivation) was observed in males and females in the 800 mg/kg bw/day group although this change was mild and temporary, and it was not judged to be the result of toxicity from the administration of the investigational substance.

In urinalysis, males and females in the 800 mg/kg bw/day group exhibited increase or tendency of increase in the amount of urine at the end of the administration period with tubular epithelial cells found in the urinary sediments and considered to be related to the substance. In addition, tubular epithelial cells in the urinary sediments were also found in males in the 200 mg/kg bw/day group, although this was not judged to be caused definitely by the administration of the substance due to the lack of other changes.

Haematology:No effects were seen.

Blood biochemistry: Blood biochemistry parameters of males and females in the 800 mg/kg bw/day group show effects on increased liver function: increase in phospholipids (23; 50%); in cholesterol (30; 44%) increase in gamma GTP (50; 200%) in males and females, respectively. The protein alpa2-globuline was only increased in males up to 22%. At 200 mg/kg bw these effects were not seen (or only to a very slight degree).

Organ liver effects: Males and females in the 800 mg/kg bw/day group exhibited relative liver weights increases of 37 and 25%, in males and females, respectively. In the 200 mg/kg bw group in males this increase was 8%. In histopathological examinations, hypertrophy of hepatocytes was observed in the males. The effects seen on liver are considered substance related, as the substance has an alkyl chain which will be metabolised as a fatty acid. The effect is therefore considered an adaptive effect and not considered adverse in nature.

Organ kidney effects: The organ weights of the kidneys were increased to 20 and 14%, in males and females, respectively. In the renal tubular cells of high dose males eosinophilic droplets were seen. In combination with the higher alpha2-globulin increase in males these are considered related to the alpha-hydrocarbon nephropathy, being a male rat specific phenomenon. The tubular epithelial cells in the urine are also anticipated to be related to this effect too. The observed increase in urinary volume did not show a dose relationship, and did not show a statistical significant increase in the high dose group.

Other organ effects including reproductive toxicity organs: No other effects were observed.

Reproductive toxicity-Fertility: In reproductive capacity tests, there were no effects of administration of the investigational substance on average sexual cycles, rate of incidence of abnormal sexual cycles, coitus ability, and fertility. Abnormal delivery conditions were not observed in any of the administration groups at observations during deliveries. No effects of administration of the investigational substance on the gestation period, corpus luteum count, number of implantation sites, implantation rate and rate of deliveries were observed in the dams.

Reproductive toxicity-Developmental toxicity: In terms of the offspring, there were no effects of administration of the investigational substance on the number of offspring, birth rate, sex ratio, body weight on Day 0 and Day 4 of nursing period, number of surviving offspring, and rate of surviving offspring after nursing period, and no abnormalities related to administration of the investigational substance were observed in external inspections of the new borns or autopsies on Day 4 of the nursing period. Based on the absence of adverse effects on reproductive and developmental parameters, the NOAEL for reproductive toxicity and for developmental toxicity is >=800 mg/kg bw/day.

Summary of the effects and the derivation of the NOAEL in the OECD TG 422. The observed effects on liver are considered to be adaptive in nature. The 800 mg/kg bw is considered to be the close maximum tolerable dose considering the metabolic capacity of the liver as the substance is readily absorbed and metabolised. The absence of liver effect after the recovery period supports this. The effects on the kidneys are considered adaptive too, not related to any dysfunction of this organs or are considered to be specific to male rats.

Systemic effects: Therefore it is concluded that no adverse systemic effects were observed >= 800 mg/kg bw/day

Reproductive toxicity, fertility and developmental: Based on the absence of adverse effects at 800 mg/kg bw/day, the NOAEL for fertility and developmental toxicity is >= 800 mg/kg bw/day.