2,6,10-trimethylundec-9-enal

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Description of key information

Administration of the test article to the dams at dosages as high as 3000 mg/kg/day did not affect the averages for the durations of gestation. No malformations or gross lesions occurred for the pups that were attributable to the test article. The NOAEL for maternal toxicity was 300 mg/kg/day and the NOAEL for pup viability was between 300 and 1500 mg/kg/day.

Link to relevant study records

Reference

Endpoint:

screening for reproductive / developmental toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1989

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Remarks:

The study was performed on a similar substance to the registered substance and as such is considered to be sufficient to address the endpoint by read-across.

Qualifier:

according to guideline

Guideline:

other: U.S. Food and Drug Administration (1966). Guidelines for Reproduction Studies for Safety Evaluation of Drugs for Human Use.

GLP compliance:

not specified

Limit test:

no

Specific details on test material used for the study:

Batch 32158
Clear colorless liquid

Species:

rat

Strain:

other: Crl:CD®(SD)BR

Details on species / strain selection:

This strain of rat was selected because it has been demonstrated to be sensitive to reproductive and developmental toxicants, widely used for reproductive toxicity evaluation and the existence of historical data and experience.

Sex:

female

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on exposure:

B212 (Melanol) was administered via oral gavage once daily to Crl: CD(SD)BR virgin female rats (ten rats per group) at doses of 0 (vehicle, corn oil) , 300 , 1500 and 3000 mg/Kg/day. All doses were given at 5 mL/kg/day and adjusted daily for body weight changes. Appropriate dosages of test article were given to the female rats for seven days prior to and then through cohabitation (maximum of seven days), gestation, delivery and a four-day lactation/postparturition period (dams that delivered litters).

Details on mating procedure:

Mating / day 0 of presumed gestation was identified on the basis of spermatozoa present in vaginal smear and/or copulatory in situ.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

performed by sponsor

Duration of treatment / exposure:

28-37 days

Frequency of treatment:

Daily

Details on study schedule:

Appropriate dosages of test article were given to the female rats for seven days prior to and then through cohabitation (maximum of seven days), gestation, delivery and a four-day lactation/postparturition period (dams that delivered litters).

Dose / conc.:

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

Dose / conc.:

1 500 mg/kg bw/day (actual dose received)

Dose / conc.:

3 000 mg/kg bw/day (actual dose received)

No. of animals per sex per dose:

10 female rats per group

Control animals:

yes, concurrent vehicle

Details on study design:

Upon arrival, the female rats were assigned two per cage on the basis of a computer-generated randomization procedure. Each female rat was individually identified with a Monel® self-piercing ear tag inscribed with the rat's designated unique number. The male breeder rats were similarly randomized upon arrival and individually identified. The 40 female rats were selected for study on the basis of physical appearance and body weight. A second computer-generated (weight-ordered) randomization procedure was performed to assign these female rats to the dosage groups. Following seven days of test article administration, the female rats were assigned to cohabitation with untreated male rats. One male was paired with one female rat for a maximum of seven days. Female rats with spermatozoa observed in smears of vaginal contents and/or copulatory plugs observed in
situ were considered to be at day O of presumed gestation and assigned to individual housing. All dams were permitted to deliver and nurse their litters during a four-day lactation period (day 1 of lactation/postparturition
was defined as the day the first pup was delivered). All dams and their pups were sacrificed with carbon dioxide on day 4 of lactation. All dams were examined for gross lesions of the thoracic and abdominal viscera. The same necropsy procedures were used for rats that were found dead or sacrificed moribund on the days these events occurred. Dams that did not deliver a litter were sacrificed on day 25 of presumed gestation. Pups that were stillborn or found dead were necropsied. Adult and pup tissues with gross lesions present were preserved in neutral buffered 10% formalin.

Parental animals: Observations and examinations:

All female rats were observed for viability at least twice each day of the study. In addition, these rats were observed for clinical signs and general health one or two times during the acclimation period (recorded by exception) and for clinical signs, general health (including delivery of a litter) and/or pharmacotoxic effects daily during the dosage period (immediately prior to and then within 60 minutes after intubation). Maternal behavior of the dams was evaluated daily when the pups were examined during the four-day lactation period. Specific maternal behavioral observations were recorded on days 1 and 4 postparturition, when the pups were weighed. Variations from expected maternal behavior were recorded by exception during each day of the lactation period. Body weights for the female rats were recorded at least once weekly during the acclimation period and daily during the dosage period. Feed consumption was recorded weekly during the premating period; on days 0, 6, 14, 16, 21 and 25 during the presumed gestation period; and on days 1 and 4 of the lactation period. Mating performance was evaluated daily (vaginal smear) during the cohabitation period and confirmed by observation of pregnancy (implantation sites present in utero on day 25 of presumed gestation, or natural delivery of a litter). The female rats were evaluated for duration of gestation (day 0 of presumed gestation to the day the first pup was delivered), litter size (live and dead pups and live pups only), and pup viability. Pups that either appeared stillborn or that died before initial examination of the litter for viability were examined for vital status at birth. The lungs were removed and immersed in water. Pups with lungs that sank were considered stillborn; pups with lungs that floated were considered liveborn and to have died shortly after birth. Dams that did not deliver litters were sacrificed with carbon dioxide on day 25 of presumed gestation and examined for gross lesions and implantation sites. On day 4 of lactation all dams that delivered litters were sacrificed with carbon dioxide and examined for gross lesions. Ovaries from all dams and any observed gross lesions were preserved in neutral buffered 10% formalin for possible future evaluation.

Litter observations:

Vital status at birth was determined for pups that either appeared stillborn or that died before the initial examination of the litter for viability(the lungs were removed and immersed in water: if the lungs sank, the pup were considered stillborn; if the lungs floated, the pup was considered liveborn and to have died shortly after birth. Each litter was evaluated for viability at least twice each day during the four-day lactation period. Dead pups observed at these times were removed. When not precluded by autolysis and/or cannibalization by the dam, dead or stillborn pups were necropsied and examined for the cause of death. Tissues with observed gross lesions were preserved in neutral buffered 10% formalin for possible future evaluation. The pups present in each litter were counted once each day. Physical signs (including nursing behavior and gross external physical anomalies) were recorded for the pups once each day during the four-day lactation period. Pup body weights were recorded on days 1 (birth) and 4 postparturition.

Postmortem examinations (offspring):

Vital status at birth was determined for pups that either appeared stillborn or that died before the initial examination of the litter for viability (the lungs were removed and immersed in water: if the lungs sank, the pup were considered stillborn; if the lungs floated, the pup was considered liveborn and to have died shortly after birth. Dead pups observed during the lactation period, if not precluded by autolysis and/or cannibalization by the dam, were necropsied and examined for the cause of death. Tissues with observed gross lesions were preserved in neutral buffered 10% formalin for possible future evaluation.

Statistics:

Maternal and pup incidence dataa were analyzed using the Variance Test for Homogeneity of the Binomial Distribution. Baseline maternal body weight data, body weight changes during the premating, gestation and lactation periods, feed consumption data, and litter averages for pup body weights and percentage of male pups were analyzed using Bartlett's Test of Homogeneity of Variances and the Analysis of Variance, when appropriate (i.e., Bartlett's Test was not significant, P>0.05). If the Analysis of Variance was significant (P~0.05), Dunnett's Test was used to identify the statistical significance of individual groups. If the Analysis of Variance was not appropriate [i.e., Bartlett's Test was significant (P~0.05)], the Kruskal-Wallis Test was used when 75% or fewer ties were present; when more than 75% ties were present, the Fisher's Exact Test was used. In cases where the Kruskal-Wallis Test was statistically significant (P~0.05), Dunn's Method of Multiple Comparisons was used to identify statistical significance of individual groups. Natural delivery parameters involving discrete data were evaluated using the Kruskal-Wallis Test procedures previously described.

Reproductive indices:

mating & fertility

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

Clinical signs that occurred for rats that died were considered effects of the high dosage of the test article and included decreased motor activity, excess salivation, oral exudate, urine-stained abdominal fur and chromodacryorrhea. At necropsy, each (P~0.01) of these rats had externally evident urine-stained abdominal fur and slight salivation or clear exudate around the nose and mouth. One of these rats had a pale, mottled liver.
Other clinical observations attributed to the test article included excess salivation (low, middle and high dosage groups), decreased motor activity, oral exudate, bradypnea, urine-stained abdominal fur (middle and high dosage groups), labored breathing, ataxia, impaired righting reflex and chromodacryorrhea (high dosage group). During the premating period, decreased motor activity occurred for significant (P~0.01) numbers of middle and high dosage group rats, and excess salivation occurred for significant (P~0.01) numbers of middle dosage group rats. During gestation, excess salivation occurred for significant (P~0.01) numbers of middle and high dosage group rats, and decreased motor activity and ataxia occurred for significant (P~0.01) numbers of high dosage group rats.

Mortality:

mortality observed, treatment-related

Description (incidence):

The high dosage of B212 caused the moribund sacrifice or death of eight (P~0.01) rats during the premating period. These events occurred on days 2 (five rats), 3 (two rats) or 4 (one rat) of the study.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Body weight gains were inhibited during the premating period for each group given the test article, as compared with the control group values. Significant (P~0.01) weight loss that occurred for the high dosage group after the first dosage was given resulted in a significant (P~0.01) decrease in the average maternal body weight for this group on day 2 of the study. Average body weights of the middle and high dosage groups were significantly decreased (P~0.01) on day 3 of the study. Despite significant (P~0.05) increases in average maternal body weight gains in the middle and high dosage groups on days 3 to 4 of the study, observations that were considered to be rebound phenomena, the average body weights of the middle dosage group were also significantly decreased (P~0.05) on days 6 and 7 of the study, and those of the high dosage group were also significantly decreased (P~0.05 to P~0.01) on days 4 through 7 of the study. There were no dosage-dependent differences in the average maternal body weight changes of the control, low and middle dosage groups during the four-day lactation period, although decreased average maternal body weight persisted for the middle dosage group.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

Significant (P~0.05 to P~0.01) decreases in absolute and/or relative feed consumption values occurred during the premating period for the rats in the 300 and 1500 mg/kg/day groups given B212 (Melonal), as compared with the control group values. Feed consumption values were significantly increased (P~0.01) for the 3000 mg/kg/day group, an observation that was probably interrelated with excessive feed spillage, commonly associated with excess salivation. Biologically important decreases in absolute and relative maternal feed consumption values occurred for the middle dosage group during the lactation period, as compared with the control group values. Absolute and relative feed consumption values were generally slightly increased for the middle and high dosage groups (the relative feed consumption value for the middle dosage group was significantly increased (P~0.05) on days 14 to 16 of gestation). Decreases in absolute and relative maternal feed consumption values occurred for the middle dosage group during the lactation period, as compared with the control group values.

Food efficiency:

not specified

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

not specified

Ophthalmological findings:

not specified

Haematological findings:

not specified

Clinical biochemistry findings:

not specified

Urinalysis findings:

not specified

Behaviour (functional findings):

effects observed, treatment-related

Description (incidence and severity):

Functional findings included excess salivation (low,middle and high dosage groups), decreased motor activity, oral exudate, bradypnea, urine-stained abdominal fur (middle and high dosage groups), labored breathing, ataxia, impaired righting reflex and chromodacryorrhea (high dosage group). During the premating period, decreased motor activity occurred for significant (P~0.01) numbers of middle and high dosage group rats, and excess salivation occurred for significant (P~0.01) numbers of middle dosage group rats. During gestation, excess salivation occurred for significant (P~0.01) numbers of middle and high dosage group rats, and decreased motor activity and ataxia occurred for significant (P~0.01) numbers of high dosage group rats.

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Histopathological findings: non-neoplastic:

not specified

Histopathological findings: neoplastic:

not specified

Reproductive function: oestrous cycle:

not examined

Reproductive function: sperm measures:

not specified

Reproductive performance:

no effects observed

Dosages of B212 (Melonal) as high as 1500 mg/kg/day did not affect mating or fertility of the female rats.

Key result

Dose descriptor:

NOAEL

Effect level:

>= 300 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

female

Basis for effect level:

clinical signs

Clinical signs:

not examined

Mortality:

not examined

Body weight and weight changes:

not examined

Food consumption and compound intake (if feeding study):

not examined

Food efficiency:

not examined

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

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

not examined

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

not examined

Histopathological findings: neoplastic:

not examined

Other effects:

not examined

Reproductive function: oestrous cycle:

not examined

Reproductive function: sperm measures:

not examined

Reproductive performance:

not examined

Clinical signs:

no effects observed

Dermal irritation (if dermal study):

not examined

Mortality / viability:

mortality observed, treatment-related

Description (incidence and severity):

Pup viability was significantly decreased (P<0.05 to P<0.01) for the middle and high dosage groups.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Body weights were significantly decreased (P<0.05) for the middle dosage group litters on day 1 postparturition, and the only delivered high dosage group litter weighed remarkably less than the control group value.

Food consumption and compound intake (if feeding study):

not examined

Food efficiency:

not examined

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

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Sexual maturation:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

no effects observed

Histopathological findings:

no effects observed

Other effects:

not examined

Behaviour (functional findings):

not examined

Developmental immunotoxicity:

not examined

Key result

Dose descriptor:

NOAEL

Generation:

F1

Effect level:

> 300 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

body weight and weight gain

Clinical signs:

not examined

Dermal irritation (if dermal study):

not examined

Mortality / viability:

not examined

Body weight and weight changes:

not examined

Food consumption and compound intake (if feeding study):

not examined

Food efficiency:

not examined

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

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Sexual maturation:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

not examined

Histopathological findings:

not examined

Other effects:

not examined

Behaviour (functional findings):

not examined

Developmental immunotoxicity:

not examined

Key result

Reproductive effects observed:

no

Lowest effective dose / conc.:

1 500 mg/kg bw/day

Treatment related:

yes

Relation to other toxic effects:

not specified

Dose response relationship:

yes

Relevant for humans:

yes

Conclusions:

Based on the data of this study, the maternal no-observable-adverse-effect-level (NOAEL) for B212 was 300 mg/Kg/day. The NOAEL for the B212 in the offspring was greater than 300 mg/Kg/day and less than 1500 mg/Kg/day. Thus, B212 was not uniquely hazardous to reproductive performance in female rats nor in the growth and development of their offspring.

Executive summary:

Melanol was administered via oral gavage once daily to Crl:CD(SD)BR virgin female rats (10 per group) at doses of 0, 300, 1500 and 3000 mg/kg/day in corn oil. Doses of Melonal were given to the female rats for seven days prior to and through cohabitation (maximum seven days), gestation, delivery and a four-day lactation/postparturition period (for dams that delivered litters). The maternal no-observable-adverse-effect-level (NOAEL) for Melanol was 300 mg/kg/day. Rats in the 1500 and 3000 mg/kg/day dose group had clinical signs and significant (P~0.05 to P~0.01) decreases in absolute and relative feed consumption values and body weight averages during the premating period with mortality in the high dose group. Mating and fertility of treated rats (up to 1500 mg/kg/day) were similar to that of the control group rats. The NOAEL for Melanol in the offspring was greater than 300 mg/kg/day and less than 1500 mg/kg/day. Significant decreases in pup body weights at birth and pup viability occurred in the middle dose group, as compared with the control group values. Thus, Melonal was not uniquely hazardous to reproductive performance in female rats nor in the growth and development of their offspring.

Effect on fertility: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

3 000 mg/kg bw/day

Study duration:

subchronic

Species:

rat

Effect on fertility: via inhalation route

Endpoint conclusion:

no study available

Effect on fertility: via dermal route

Endpoint conclusion:

no study available

Effects on developmental toxicity

Effect on developmental toxicity: via oral route

Endpoint conclusion:

no study available

Effect on developmental toxicity: via inhalation route

Endpoint conclusion:

no study available

Effect on developmental toxicity: via dermal route

Endpoint conclusion:

no study available

Justification for classification or non-classification

In view of the lack in affect on fertility displayed in the study available for the test material's structural analogue, no classification in accordance with Regulation (EC) No. 1272/2008 is required for this endpoint.