Methyl dodec-9-enoate

Repeated dose toxicity: oral

Administrative data

Endpoint:

sub-chronic toxicity: oral

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

2015

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Read-across from a study performed according to GLP and guideline. Read-across justification: A comparison target substance (9DDAME) and the read-across substance (9DAME) shows that the two substances share structural similarities, increasing from a chain length of C10 to C12 with similar functional groups and also have ‘mechanistic action’ similarities.

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2015

Report date:

2015

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 408 (Repeated Dose 90-Day Oral Toxicity Study in Rodents)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

methyl 9-decenoate

EC Number:

662-772-0

Cas Number:

25601-41-6

Molecular formula:

C11H20O2

IUPAC Name:

methyl 9-decenoate

Details on test material:

- Name of test material (as cited in study report): 9-Decenoic Acid, Methyl Ester (9DAME)
- Physical state: Clear, colorless liquid
- Analytical purity: 99.1%
- Purity test date: Dec-2014, May-2015
- Lot/batch No.: Lot no. E140124-1
- Expiration date of the lot/batch: 07-May-2015
- Stability under test conditions: Analyses showed test material was stable under storage and use conditions
- Storage condition of test material: The test item was stored refrigerated (2°C to 8°C), protected from light, under nitrogen, and was considered stable under these conditions.

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories, Inc., Raleigh, NC
- Age at study initiation: approximately 37 days old at receipt
- Housing: animals were housed 2 to 3 per cage by sex in clean, solid bottom cages containing ground corncob bedding material (Bed O’Cobs®)
- Diet (e.g. ad libitum): PMI Nutrition International, LLC, Certified Rodent LabDiet® 5002 (meal) ad libitum
- Water (e.g. ad libitum): Reverse osmosis treated (on site) drinking water ad libitum
- Acclimation period: 14 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 69.1°F to 72.0°F (20.6°C to 22.2°C)
- Relative Humidity (%): 35.2% to 64.7%
- Air changes (per hr): a minimum of 10 fresh air changes per hour
- Photoperiod (hrs dark / hrs light): 12 hour light (0600 hours to 1800 hours)/12 hour dark photoperiod

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on oral exposure:

PREPARATION OF DOSING SOLUTIONS: The test item formulations were prepared approximately weekly as single formulations for each dosage level, divided into aliquots for daily dispensation, and stored refrigerated (2°C to 8°C), protected from light, under nitrogen. The test item formulations were stirred continuously throughout the preparation, sampling, and for at least 30 minutes prior to the start of the dose administration procedures.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Analyses to determine stability and homogeneity of dosing formulations were conducted prior to initiation of the 90-day treatment period. Samples for concentration analysis were collected during study weeks 0, 3, 7, and 12 from the middle stratum of each dosing formulation (including the control group). All analyses were conducted by the WIL Research Analytical Chemistry Department using a validated gas chromatography with flame ionization detection method.

Duration of treatment / exposure:

90 days

Frequency of treatment:

daily

Doses / concentrations

Remarks:

Doses / Concentrations:
0, 100, 300 or 1000 mg/kg/day
Basis:
actual ingested

No. of animals per sex per dose:

10 males and 10 females per group
Recovery animals: 5 males and 5 females in the control and high-dose groups

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: The high dosage level was the limit dose based on the absence of findings reported by the Sponsor in earlier studies of the test item (14- and 28-day gavage) at 1000 mg/kg/day). The low dosage level was included to help assure a no observed adverse effect level.

Positive control:

no

Examinations

Observations and examinations performed and frequency:

SURVIVAL
All animals were observed twice daily, once in the morning and once in the afternoon, for mortality and moribundity.

CLINICAL OBSERVATIONS
Clinical examinations were performed at the time of dose administration and 1-2 hours following dose administration. During the recovery period, the animals were observed once daily. Detailed physical examinations were conducted on all animals 1 week (± 2 days) prior to randomization, on the day of randomization, weekly (± 2 days) during the study period, and on the days of the scheduled necropsies.

BODY WEIGHTS
Individual body weights were recorded 1 week (± 2 days) prior to randomization, on the day of randomization, study day 0 (prior to dosing), weekly (± 2 days) during the study period, and on the day prior to the first day of the scheduled necropsies (nonfasted).

FOOD CONSUMPTION
Cage food weights were recorded weekly (± 2 days) beginning following randomization and throughout the study period. Food consumption was normalized to the number of animals/cage and calculated as g/animal/day. The last food weights were collected on the day prior to the final day of study week 12 (primary necropsy) or 16 (recovery necropsy).

FUNCTIONAL OBSERVATIONAL BATTERY ASSESSMENTS
Functional observational battery (FOB) assessments were recorded for all animals during study week 11/12 (designated as study week 12 for report presentation purposes). Assessments were conducted prior to dose administration. The FOB utilized at WIL Research is based on previously developed protocols (Gad, 1982; Haggerty, 1989; Irwin, 1968; Moser et al., 1988; Moser et al., 1991; and O’Donoghue, 1989). Testing was performed by the same biologists, whenever possible, without knowledge of the animal’s group assignment. The FOB was performed in a sound attenuated room equipped with a white noise generator set to operate at 70 ± 10 dB. All animals were observed for the following parameters: HOME CAGE OBSERVATIONS – Posture, Convulsions/tremors, Feces consistency, Biting, Palpebral (eyelid) fissure; HANDLING OBSERVATIONS - Ease of removal from cage, Lacrimation/chromodacryorrhea, Piloerection, Palpebral closure, Eye prominence, Red/crusty deposits, Ease of handling animal in hand, Salivation, Fur appearance, Respiratory rate/character, Mucous membranes/eye/skin color. Muscle tone; OPEN FIELD OBSERVATIONS – Mobility, Rearing, Convulsions/tremors, Grooming, Bizarre/stereotypic behavior, Time to first step (seconds), Gait, Arousal, Urination/defecation, Gait score, Backing (Note: Open field observations were evaluated over a 2-minute observation period); SENSORY OBSERVATIONS - Approach response, Startle response, Pupil response, Forelimb extension, Air righting reflex, Touch response, Tail pinch response, Eyeblink response, Hindlimb extension, Olfactory orientation; NEUROMUSCULAR OBSERVATIONS - Hindlimb extensor strength, Hindlimb foot splay, Grip strength hind and forelimb, Rotarod performance; PHYSIOLOGICAL OBSERVATIONS – Catalepsy, Body temperature, Body weight.

MOTOR ACTIVITY
Motor activity was assessed for all animals during study week 11/12. The motor activity assessment was conducted prior to dose administration. Motor activity, recorded after the completion of the FOB, assessment was conducted using a personal computer controlled system that utilizes a series of infrared photobeams surrounding an amber, plastic rectangular cage to quantify each animal’s motor activity. Four-sided black plastic enclosures were used to surround the transparent plastic boxes and decrease the potential for distraction from extraneous environmental stimuli or activity by biologists or adjacent animals. The motor activity assessment was performed in a sound attenuated room equipped with a white noise generator set to operate at 70 ± 10 dB. Each animal was tested separately. Data were collected in 5 minute epochs (print intervals) and the test session duration was 60 minutes. These data were compiled as six, 10-minute subintervals for tabulation. Data for ambulatory and total motor activity were tabulated. Total motor activity was defined as a combination of fine motor skills (i.e., grooming, interruption of 1 photobeam) and ambulatory motor activity (interruption of 2 or more consecutive photobeams).

CLINICAL PATHOLOGY
Blood and urine samples for clinical pathology evaluations (hematology, coagulation, serum chemistry, and urinalysis) were collected from all animals assigned to the scheduled necropsies (study weeks 12/13 and 16/17; designated as study weeks 12 and 16, respectively, for report presentation purposes). The animals were fasted overnight prior to blood collection while in metabolism cages for urine collection. Blood was collected for hematology and serum chemistry evaluation via the retro-orbital sinus of animals anesthetized by inhalation of isoflurane. Blood was collected for coagulation parameters at the time of euthanasia via the vena cava of animals euthanized by inhalation of carbon dioxide. The following parameters were evaluated:

HEMATOLOGY AND COAGULATION - Total leukocyte count, Erythrocyte count, Hemoglobin, Hematocrit, Mean corpuscular volume, Mean corpuscular hemoglobin, Mean corpuscular hemoglobin concentration, Platelet count, Prothrombin time, Activated partial thromboplastin time, Reticulocyte count (Percent, Absolute), Mean platelet volume, Differential leukocyte count, Red cell distribution width, Hemoglobin distribution width, Platelet estimate, Red cell morphology.

SERUM CHEMISTRY – Albumin, Total protein, Globulin [by calculation], Albumin/globulin ratio (A/G Ratio) [by calculation], Total bilirubin, Urea nitrogen, Creatinine, Alkaline phosphatase, Alanine aminotransferase, Aspartate aminotransferase, Gamma glutamyltransferase, Glucose, Total cholesterol, Calcium, Chloride, Phosphorus, Potassium, Sodium, Sorbitol dehydrogenase, Triglycerides, Appearance.

URINALYSIS - Specific gravity, pH, Urobilinogen, Total volume, Color, Clarity, Protein, Glucose, Ketones, Bilirubin, Occult blood, Leukocytes, Nitrites, Microscopy of sediment.

OPHTHALMIC EXAMINATIONS
Ocular examinations were conducted on all animals during acclimation (29-Jan-2015; study week -1) and near the end of the dosing period (30-Apr-2015; study week 12). All ocular examinations were conducted using an indirect ophthalmoscope and slit lamp biomicroscope preceded by pupillary dilation with an appropriate mydriatic agent.

Sacrifice and pathology:

A complete necropsy was conducted on all animals.

ORGAN WEIGHTS
The following organs were weighed from all animals at the scheduled necropsies: Adrenals. Brain, Epididymides, Heart, Kidneys, Liver, Ovaries with oviducts, Pituitary, Prostate with seminal vesicles, Spleen, Testes, Thymus, Thyroid with parathyroids, Uterus.

MICROSCOPIC EXAMINATION
Microscopic examination was performed on tissues from all animals in the control and 1000 mg/kg/day groups at the primary necropsy. In addition, gross lesions were prepared from all animals in the 100 and 300 mg/kg/day groups at the primary necropsy and from all animals at the recovery necropsy.

Statistics:

Body weight, body weight change, food consumption, continuous FOB, clinical pathology, and organ weight data were subjected to a parametric one way ANOVA (Snedecor and Cochran, 1980) to determine intergroup differences. If the ANOVA revealed statistically significant (p<0.05) intergroup variance, Dunnett's test (Dunnett, 1964) was used to compare the test item treated groups to the control group. Functional observational battery parameters that yielded scalar or descriptive data were analyzed using Fisher’s Exact Test (Steel and Torrie, 1980).

All repeated measures analysis of variance (RANOVA) statistical analyses for total and ambulatory motor activity counts recorded during study week 11/12 were conducted by BioSTAT Consultants, Inc., Portage, MI, using SAS® version 9.2 software (SAS Institute, Inc., 2002-2008). Each analysis endpoint was analyzed, by sex and session, with a RANOVA.

Results and discussion

Results of examinations

Clinical signs:

no effects observed

Mortality:

no mortality observed

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

no effects observed

Ophthalmological findings:

no effects observed

Haematological findings:

no effects observed

Clinical biochemistry findings:

no effects observed

Urinalysis findings:

no effects observed

Behaviour (functional findings):

no effects observed

Organ weight findings including organ / body weight ratios:

no effects observed

Gross pathological findings:

no effects observed

Histopathological findings: non-neoplastic:

no effects observed

Histopathological findings: neoplastic:

no effects observed

Details on results:

All animals survived to the scheduled necropsies. There were no test item-related effects on body weights, food consumption, functional observational battery parameters, motor activity, or organ weights. Hematology, coagulation, serum chemistry, and urinalysis parameters were unaffected by test item administration. There were no test item-related ophthalmic, macroscopic, or microscopic findings.
Test item-related, nonadverse findings were noted at 1-2 hours post-dosing during the 90 day treatment period and included clear material around the mouth and/or ventral neck in the 300 and 1000 mg/kg/day group males and clear material around the mouth in the 1000 mg/kg/day group females. These findings were not noted during the recovery period.

Effect levels

Dose descriptor:

NOAEL

Effect level:

1 000 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: highest dose tested

Target system / organ toxicity

Critical effects observed:

not specified

Applicant's summary and conclusion

Conclusions:

Based on the results of this study, oral administration of 9-Decenoic Acid, Methyl Ester (9DAME) to Sprague Dawley rats for a minimum of 90 days was well tolerated at dosage levels of 100, 300, and 1000 mg/kg/day. Treatment-related findings were limited to nonadverse clinical observations in the 300 and 1000 mg/kg/day group males and 1000 mg/kg/day group females. Therefore, the no-observed-adverse-effect level (NOAEL) was considered to be 1000 mg/kg/day.

Executive summary:

9-Decenoic Acid, Methyl Ester (9DAME), in the vehicle (corn oil) was administered orally by gavage once daily for a minimum of 90 consecutive days to Crl:CD(SD) rats. Dosage levels were 100, 300, and 1000 mg/kg/day. A concurrent control received the vehicle (corn oil). The dose volume was 4 mL/kg for all groups. Following a minimum of 90 days of dose administration, 10 animals/sex/group were euthanized; the remaining 5 animals/sex in the control and high-dose groups were euthanized following a minimum 28 day nondosing (recovery) period.

 

All animals were observed twice daily for mortality and moribundity. Clinical examinations were performed daily, and detailed physical examinations were performed weekly (± 2 days). Individual body weights were recorded weekly (± 2 days). Cage food weights were recorded weekly (± 2 days) beginning following randomization. Functional observational battery (FOB) and motor activity data were recorded for all animals during study week 11/12. Ophthalmic examinations were performed during study weeks -1 and 12. Clinical pathology parameters (hematology, coagulation, serum chemistry, and urinalysis) were analyzed for all animals assigned to the primary (study week 12/13) and recovery (study week 16/17) necropsies. Complete necropsies were conducted on all animals, and selected organs were weighed at the scheduled necropsies. Selected tissues were examined microscopically from all animals in the control and high-dose groups at the primary necropsy. Gross lesions were examined microscopically from all animals.

 

All animals survived to the scheduled necropsies. There were no test item-related effects on body weights, food consumption, functional observational battery parameters, motor activity, or organ weights. Hematology, coagulation, serum chemistry, and urinalysis parameters were unaffected by test item administration. There were no test item-related ophthalmic, macroscopic, or microscopic findings.

 

Test item-related, nonadverse findings were noted at 1-2 hours post-dosing during the 90 day treatment period and included clear material around the mouth and/or ventral neck in the 300 and 1000 mg/kg/day group males and clear material around the mouth in the 1000 mg/kg/day group females. These findings were not noted during the recovery period.

 

Based on the results of this study, oral administration of 9-Decenoic Acid, Methyl Ester (9DAME) to Sprague Dawley rats for a minimum of 90 days was well tolerated at dosage levels of 100, 300, and 1000 mg/kg/day. Treatment-related findings were limited to nonadverse clinical observations in the 300 and 1000 mg/kg/day group males and 1000 mg/kg/day group females. Therefore, the no-observed-adverse-effect level (NOAEL) was considered to be 1000 mg/kg/day.