Mentha citrata, ext.

Toxicity to reproduction

Administrative data

Endpoint:

screening for reproductive / developmental toxicity

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Justification for type of information:

Data from peer reviewed journal

Data source

Reference

Reference Type:

publication

Title:

Evaluation of the Developmental Toxicity of test material in Rats

Author:

V.T. Politano. et al

Year:

2008

Bibliographic source:

International Journal of Toxicology,2008

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

other: International Conference on Harmonisation (ICH) Harmonized Tripartite Guideline stages C and D of the reproductive process.

Principles of method if other than guideline:

Reproductive and developmental toxicity study of test material was performed on Crl:CD(SD) IGS BR VAF/Plus rats by oral gavage.

GLP compliance:

not specified

Limit test:

no

Justification for study design:

No data available

Test material

Test material information

Constituent 1

Reference substance name:

Linalool

EC Number:

201-134-4

EC Name:

Linalool

Cas Number:

78-70-6

Molecular formula:

C10H18O

IUPAC Name:

(3S)-3,7-dimethylocta-1,6-dien-3-ol

Details on test material:

- Name of test material (as cited in study report):Linalool
- Molecular formula :C10H18O
- Molecular weight :154.251g/mol
- Substance type:Organic
- Physical state: Liquid

Test animals

Species:

rat

Strain:

other: Crl:CD(SD) IGS BR VAF/Plus

Details on species / strain selection:

No data available

Sex:

female

Details on test animals or test system and environmental conditions:

Details on test animals and env. conditions
TEST ANIMALS
- Source: Charles River Laboratories,
Raleigh, NC
- Age at study initiation: (P) x wks; (F1) x wks
- Weight at study initiation: Females: 207 to 253 g.
- Fasting period before study:
- Housing: The rats were assigned to individual housing (stainless steel, wire-bottomed cages)
- Use of restrainers for preventing ingestion (if dermal): yes/no
- Diet (e.g. ad libitum): Certified Rodent Diet 5002 (PMI Nutrition International, St. Louis,MO) were provided ad libitum to the rats.
- Water (e.g. ad libitum): reverse-osmosis deionized water were provided ad libitum to the rats.
- Acclimation period:

ENVIRONMENTAL CONDITIONS
- Temperature (°C):17.77 °C -26.11°C
- Humidity (%):30% to 70%
- Air changes (per hr): at least ten changes per hour
of 100% fresh air passed through 99.97% HEPA filters
- Photoperiod (hrs dark / hrs light): a 12:12-h light dark lighting cycle.

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:
The test material diluted with corn oil
DIET PREPARATION
- Rate of preparation of diet (frequency):
- Mixing appropriate amounts with (Type of food ):
- Storage temperature of food: No data available
VEHICLE
- Justification for use and choice of vehicle (if other than water): Test material dissolved in corn oil
- Concentration in vehicle: 0,250, 500, or 1000 mg/kg/day
- Amount of vehicle (if gavage): 10ml/kg

- Lot/batch no. (if required): 015K0115
- Purity: No data available

Details on mating procedure:

- M/F ratio per cage:1:1
- Length of cohabitation:
- Proof of pregnancy: [vaginal plug / sperm in vaginal smear] referred to as [day 0 / day 1] of pregnancyThe presence of spermatozoa or a copulatory plug was designated as gestational day 0 (GD 0).
- After ... days of unsuccessful pairing replacement of first male by another male with proven fertility.
- Further matings after two unsuccessful attempts: [no / yes (explain)]
- After successful mating each pregnant female was caged (how):
- Any other deviations from standard protocol:

Analytical verification of doses or concentrations:

yes

Duration of treatment / exposure:

11 days (Days 7 to 17 of gestation )

Frequency of treatment:

once daily

Details on study schedule:

No data available

Doses / concentrations

Remarks:

0,250, 500, or 1000 mg/kg/day

No. of animals per sex per dose:

Total:100
0 mg/kg bw: 25 female
250 mg/kg bw: 25female
500 mg/kg bw: 25 female
1000mg/kg bw: 25 female

Control animals:

yes, concurrent vehicle

Details on study design:

No data available

Positive control:

No data available

Examinations

Parental animals: Observations and examinations:

Parental animals observation and examinations
CAGE SIDE OBSERVATIONS: yes

DETAILED CLINICAL OBSERVATIONS: Yes

Time schedule: twice daily.

BODY WEIGHT: Yes

Time schedule for examinations: Body
weights were recorded prior to the start of the study and daily during the dosage and postdosage periods.
FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): Yes Feed consumption was recorded on GDs 0, 7, 10, 12, 15, 18, and 21. On GD 21
Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: No data available
Compound intake calculated as time-weighted averages from the consumption and body weight gain data: Yes / No / No data: No data available

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): No data
Time schedule for examinations:

Oestrous cyclicity (parental animals):

No data available

Sperm parameters (parental animals):

No data available

Litter observations:

Weighed, and examined for gender and gross external alterations.

Postmortem examinations (parental animals):

Postmortem examinations (Parent Animal)
SACRIFICE: yes all rats were euthanized by inhalation of carbon dioxide


GROSS NECROPSY: yes
gross necropsy of the thoracic, abdominal, and pelvic viscera was performed. Uteri of apparently nonpregnant rats were examined while pressed between glass plates to confirm the absence of implantation sites. Uteri from pregnant rats were excised and examined for number and distribution of implantations, live and dead fetuses, and early and late resorptions. The number of corpora lutea in each ovary was recorded.

HISTOPATHOLOGY / ORGAN WEIGHTS
The tissues indicated in Table [#] were prepared for microscopic examination and weighed, respectively.

Postmortem examinations (offspring):

Postmortem examinations (offspring)
SACRIFICE
- Live foetuses were euthanized by an intraperitoneal injection of pentobarbital

GROSS NECROPSY
Approximately half of the fetuses in each litter were fixed in Bouin’s solution and examined for soft tissue alterations, using a variation of Wilson’s sectioning technique (Staples 1974). The remaining fetuses in each litter were eviscerated, cleared, stained with alizarin red S (Staples and Schnell 1964), and examined for skeletal alterations

Statistics:

Data generated during the course of study were recorded either by hand or using the Argus Automated Data Collection and Management System and the Vivarium Temperature and Relative Humidity Monitoring System. All data were tabulated, summarized, and/or statistically analyzed using the above systems in conjunction with Microsoft Excel (Microsoft Office 97/2000XP), Quattro Pro 8, and/or The SAS System (version 6.12). Clinical observation and other proportion data
were analyzed using the variance test for homogeneity of the binomial distribution (Snedecor and Cochran 1967a). Continuous data were analyzed using Bartlett’s test of homogeneity of variances (Sokal and Rohlf 1969a) and the analysis of variance (Snedecor and Cochran 1967b), when appropriate. Dunnett’s test
(Dunnett 1955) was used to identify statistical significance of differences among individual groups. If the analysis of variance was not appropriate, the Kruskal-Wallis test (Sokal and Rohlf 1969b) or Dunn’s method of multiple comparisons (Dunn 1964) was used to identify the statistical significance of differences among the individual groups. If there were greater than 75% ties, Fisher’s exact test (Siegel 1956) was used to analyze the data.

Reproductive indices:

No data available

Offspring viability indices:

No data available

Results and discussion

Results: P0 (first parental generation)

General toxicity (P0)

Clinical signs:

no effects observed

Description (incidence and severity):

There were no clinical signs of toxicity.

Dermal irritation (if dermal study):

not specified

Mortality:

no mortality observed

Description (incidence):

No maternal mortality occurred during the study

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

No statistically significant differences occurred in mean body weights at necropsy or body weight gains at dosages as high as 1000 mg/kg/day However, compared to vehicle control group values, mean body weight gains were reduced by 11% in the 1000 mg/kg/day dosage group during the dosing period, whereas a compensatory 7% increase occurred during the postdosage period (GDs 18 to 21).

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

Mean maternal relative and absolute feed consumption values paralleled the body weight gains, with a statistically significant reduction at some time points in the 1000 mg/kg/day dosage group

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):

not specified

Immunological findings:

not specified

Organ weight findings including organ / body weight ratios:

not specified

Histopathological findings: non-neoplastic:

not specified

Histopathological findings: neoplastic:

not specified

Other effects:

not specified

Reproductive function / performance (P0)

Reproductive function: oestrous cycle:

not specified

Reproductive function: sperm measures:

not specified

Reproductive performance:

no effects observed

Description (incidence and severity):

Pregnancy occurred in 22 (88%), 23 (92%), 20 (80%), and
22 (84%) rats in the four respective dosage groups. One dam in the 250 mg/kg/day dosage group delivered early on the day of scheduled sacrifice; as a result, caesarean-sectioning observations on GD 21 were based on 22, 22, 20, and 22 deliveries. The early delivery was considered unrelated to test material because this incident was not dose dependent. All placentae appeared normal.The litter averages for corpora lutea, implantations, litter sizes, live fetuses, early and late resorptions, percent resorbed conceptuses, were comparable among the four dosage groups and did not significantly differ.

Effect levels (P0)

Dose descriptor:

NOAEL

Effect level:

500 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

female

Basis for effect level:

clinical signs

mortality

body weight and weight gain

food consumption and compound intake

gross pathology

reproductive performance

Remarks on result:

other: overall no effects on reproductive performance

Target system / organ toxicity (P0)

Critical effects observed:

not specified

System:

other: not specified

Organ:

not specified

Treatment related:

not specified

Dose response relationship:

not specified

Relevant for humans:

not specified

Results: F1 generation

General toxicity (F1)

Clinical signs:

not specified

Dermal irritation (if dermal study):

not specified

Mortality / viability:

no mortality observed

Body weight and weight changes:

no effects observed

Description (incidence and severity):

fetal body weights were comparable among the four dosage groups and did not significantly differ.

Food consumption and compound intake (if feeding study):

not specified

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

Sexual maturation:

not specified

Organ weight findings including organ / body weight ratios:

not specified

Gross pathological findings:

no effects observed

Description (incidence and severity):

All pups appeared normal and no gross external, soft tissue, or skeletal alterations were noted

Histopathological findings:

not specified

Other effects:

not specified

Developmental neurotoxicity (F1)

Behaviour (functional findings):

not specified

Developmental immunotoxicity (F1)

Developmental immunotoxicity:

not specified

Effect levels (F1)

Dose descriptor:

NOAEL

Generation:

F1

Effect level:

1 000 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

not specified

Basis for effect level:

viability

mortality

body weight and weight gain

gross pathology

Remarks on result:

other: overall no effects on developmental parameters

Target system / organ toxicity (F1)

Critical effects observed:

not specified

System:

other: not specified

Organ:

not specified

Treatment related:

not specified

Dose response relationship:

not specified

Relevant for humans:

not specified

Overall reproductive toxicity

Reproductive effects observed:

not specified

Treatment related:

not specified

Relation to other toxic effects:

not specified

Dose response relationship:

not specified

Relevant for humans:

not specified

Any other information on results incl. tables

Effect of oral administration of test material on maternal absolute feed consumption and maternal body weight gains.

 

	Dosage group (mg/kg/day)^a
	0 (control)	250	500	1000
Rats tested	25	25	25	25
Rats pregnant	22	23	20	22
Maternal absolute feed consumption in g/day (mean±SD)
GDs 0-7	22.4 ± 2.1	22.6 ±2.5	22.4 ±2.6	22.5± 1.8
GDs 7-10	15.8 ±2.7	17.2 ±2.7	16.4 ±3.5	13.4 ±1.8**
GDs 10-12	17.8 ±2.8	18.4 ± 2.7	18.3± 3.6	17.6 ±2.4
GDs 12-15	18.6 ±3.1	18.3 ±2.5	18.2 ±2.8	17.9± 2.1
GDs 15-18	20.5± 3.6	19.8± 3.1	19.4± 3.4	18.7±  2.6
GDs 7-18	18.2 ±2.3	18.4 ±2.0	18.0± 2.7	16.9± 1.4
GDs 18-21	23.4 ±3.5	23.5 ±2.9	22.9 ±2.6	25.4± 1.8*
GDs 7-21	19.3 ±2.2	19.5± 2.0	19.1 ±2.4	18.7 ±1.2
GDs 0-21	20.4 ±2.0	20.6 ±2.1	20.2 ±2.3	20.0± 1.2
Maternal body weight gains in g (mean±SD)
GDs 0-7	40.8 ±6.3	42.4 ±10.1	43.0± 9.5	38.9 ±8.9
GDs 7-10	9.0 ±7.6	10.3 ± 6.8	11.2 ±8.6	6.4 ±7.3
GDs 10-12	11.9 ± 5.3	12.8± 5.1	12.1 ± 4.5	12.9± 6.2
GDs 12-15	17.2 ±8.8	17.0 ±7.6	15.9 ± 6.5	18.5 ±7.3
GDs 15-18	40.5 ±11.4	36.7 ± 9.1	36.9 ± 10.4	31.9 ±10.4
GDs 7-18	78.5 ±20.1	76.8± 10.6	76.0 ±19.1	69.7 ±12.9
GDs 18-21	36.2 ± 11.8	35.4 ± 21.0	36.4 ±7.9	39.0 ± 11.9
GDs 7-21	114.8± 27.9	112.2± 25.3	112.4 ± 22.3	108.7 ± 21.8
GDs 0-21	155.6 ±30.8	154.6 ± 28.9	155.4 ±27.6	147.6 ±22.2

 

ADosing occurred on days 7 to 17 of gestation.

GD=gestational day; the presence of spermatozoa and/or copulatory

plug in situ was designated as GD 0.

∗Significantly different from the vehicle control group value

(p≤.05).

∗∗Significantly different from the vehicle control group value

(p≤.01).

 

Effect of maternal administration of test material on caesarean-section and litter data

 

	Dosage group (mg/kg/day)^a
	0 (control)	250	500	1000
Rats tested	25	25	25	25
Rats pregnant (%)	22 (88.0)	23(92.0)	20(80.0)	22(88.0)
Rats caesarean sectioned on GDs 21	22	22^b	20	22
Corpora lutea (mean±SD)	14.0 ±3.4	15.5 ±2.8	14.4 ± 3.5	14.3 ± 3.5
Implantations (mean±SD)	13.1± 3.8	14.3 ±2.3	13.4 ±2.9	12.9± 4.1
Resorptions (mean±SD)	0.4 ± 0.6	1.0 ±1.7	0.6 ±0.7	0.5 ± 0.8
Litter size (mean±SD)	12.6 ±4.2	13.3± 2.4	12.7± 3.0	12.3 ± 4.0
Fetal body weight/litter (mean±SD)	5.1± 0.7	4.8 ± 0.5	4.9± 0.5	4.9 ± 0.5
Live fetuses	277	293	254	271
Dead fetuses	4	0	0	0

aDosing occurred on days 7 to 17 of gestation.

bOne dam delivered just prior to caesarean section, data from this dam and litter excluded.

GD=gestational day; the presence of spermatozoa and/or copulatory plug in situ was designated as GD 0.

Fetal alterations observed (gross external, soft tissue, or skeletal variations or malformations) following oral administration of test material to pregnant rats

	Dosage group (mg/kg/day)a
	0 (control)	250	500	1000
Litters evaluated	22	22	20	22
Fetuses evaluated	281	293	254	271
Litters with fetuses with any observed alterations (%)	1(18.2)	6(27.3)	7(35.0)	4(18.2)
Fetuses with any observed alterations (%)	5(1.8)	6(2.0)	8(3.1)	4(1.5)
% fetuses/litter with any alteration (mean±SD)	1.6± 3.6	2.1 ±3.7	3.0 ±1.7	1.5± 3.4

aDosing occurred on days 7 to 17 of gestation.

bFour dead fetuses were excluded from summarization and statistical analyses.

GD=gestational day; the presence of spermatozoa and/or copulatory plug in situ was designated as GD 0.

Applicant's summary and conclusion

Conclusions:

The NOAEL for reproductive toxicity was considered to be 500mg/kg due to no significant reductions in body weight gain and significant reductions in feed consumption and The developmental NOAEL was considered to be greater than or equal to 1000 mg/kg/day as the test material did not reveal any teratogenic effects. When mated female rats treated with test material via oral gavage.

Executive summary:

The reproductive and developmental toxicity study oftest materialwas performed on Crl:CD(SD) IGS BR VAF/Plus rats.The study was designed and initiated to accurately evaluate the effects of test material on International Conference on Harmonisation (ICH) Harmonized Tripartite Guideline stages C and D of the reproductive process. Requirements of the FDA FDA 1994) were used as the basis for study design. All procedures were conducted in compliance with the Organization for Economic Cooperation and Development (OECD 1998), Dosages for the present study were selected on the basis of a range-finding study. The test material in a corn oil vehicle was administered by gavage to four groups of pregnant rats on GDs 7 to 17 at dosages of 0, 250, 500, or 1000 mg/kg/day. The dosage volume was 10 ml/kg, Healthy, mated female rats were then assigned to four dosage groups, 25 rats/group, using a computer-generated (weight-ordered) randomization procedure based on body weights recorded on the day on which sperm was found in the vaginal smear or a copulatory plug was found in the vagina. The presence of spermatozoa or a copulatory plug was designated as gestational day 0 (GD 0).Animals were observed twice daily for viability and examined for clinical signs, abortions, and premature deliveries before dosage administration and approximately one hour later. Body weights were recorded prior to the start of the study and daily during the dosage and postdosage periods. Feed consumption was recorded on GDs 0, 7, 10, 12, 15, 18, and 21. On GD 21, all rats were euthanized by inhalation of carbon dioxide. Following caesarean sectioning, a gross necropsy of the thoracic, abdominal, and pelvic viscera was performed. Uteri of apparently nonpregnant rats were examined while pressed between glass plates to confirm the absence of implantation sites. Uteri from pregnant rats were excised and examined for number and distribution of implantations, live and dead fetuses, and early and late resorptions. The number of corpora lutea in each ovary was recorded. Fetuses were removed from the uterus, weighed, and examined for gender and gross external alterations. Live foetuses then were euthanized by an intraperitoneal injection of pentobarbital approximately half of the fetuses in each litter were fixed in Bouin’s solution and examined for soft tissue alterations, using a variation of Wilson’s sectioning technique (Staples 1974). The remaining fetuses in each litter were eviscerated, cleared, stained with alizarin red S (Staples and Schnell 1964), and examined for skeletal alterations.

No maternal mortality occurred during the study. There were no clinical signs of toxicity. All abnormal necropsy observations on GD 21 were considered unrelated to linalool because they occurred in single animals and were unrelated to dose. No statistically significant differences occurred in mean body weights at necropsy or body weight gains at dosages as high as 1000 mg/kg/day (However, compared to vehicle control group values, mean body weight gains were reduced by 11% in the 1000 mg/kg/day dosage group during the dosing period, whereas a compensatory 7% increase occurred during the postdosage period (GDs 18 to 21). Mean maternal relative and absolute feed consumption values paralleled the body weight gains, with a statistically significant reduction at some time points in the 1000 mg/kg/day dosage group. Pregnancy occurred in 22 (88%), 23 (92%), 20 (80%), and 22 (84%) rats in the four respective dosage groups. One dam in the 250 mg/kg/day dosage group delivered early on the day of scheduled sacrifice; as a result, caesarean-sectioning observations on GD 21 were based on 22, 22, 20, and 22 deliveries. The early delivery was considered unrelated to linalool because this incident was not dose dependent. All placentae appeared normal.The litter averages for corpora lutea, implantations, litter sizes, live fetuses, early and late resorptions, percent resorbed conceptuses, percent live fetuses, and fetal body weights were comparable among the four dosage groups and did not significantly differ. There were four dead fetuses in the 0 (vehicle) mg/kg/day dosage group; no other dead fetuses were observed All pups appeared normal and no gross external, soft tissue, or skeletal alterations were noted. Hencethe NOAEL for reproductive toxicity was considered to be 500mg/kg due to non-significant reductions in body weight gain and significant reductions in feed consumptionandthe developmental NOAEL was considered to be greater than or equal to 1000 mg/kg/day asthe test material did not reveal any teratogenic effects.When mated femalerats treated withtest materialvia oral gavage.