Lemon, ext.

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:

supporting study

Study period:

no data

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

other: well-conducted study but reported in Japanese language

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

reference to same study

Cross-reference 2

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

1975

Materials and methods

Test guideline

Qualifier:

no guideline available

Principles of method if other than guideline:

A combination of rules from OECD Guidelines 409 and 452 were followed (by anticipation as thoses guidelines did not exist when the study was conducted).
d-limonene was administered by gavage to dogs for 6 months. This duration was chosen as usual when developing new medicinal products (d-limonene was explored in this study as a possible gallstone solubiliser).

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

(R)-p-mentha-1,8-diene

EC Number:

227-813-5

EC Name:

(R)-p-mentha-1,8-diene

Cas Number:

5989-27-5

Molecular formula:

C10H16

IUPAC Name:

(4R)-1-methyl-4-(prop-1-en-2-yl)cyclohexene

Constituent 2

Reference substance name:

Dipentene

EC Number:

205-341-0

EC Name:

Dipentene

Cas Number:

138-86-3

Molecular formula:

C10H16

IUPAC Name:

4-isopropenyl-1-methylcyclohexene

Details on test material:

no data

Test animals

Species:

dog

Strain:

other: Japanese beagle

Sex:

male/female

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

not specified

Details on oral exposure:

no data

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

6 months

Frequency of treatment:

once a day

Doses / concentrations

Remarks:

Doses / Concentrations:
0.4, 1.2 and 3.6 mL/kg bw/d equivalent to 340, 1000 and 3000 mg/kg bw/day
Basis:
actual ingested

No. of animals per sex per dose:

3/sex/dose

Control animals:

yes

Results and discussion

Effect levels

1

Dose descriptor:

NOAEL

Effect level:

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

Based on:

test mat.

Sex:

male

Basis for effect level:

other: Decreased body weight and protein casts observed in the renal tubule at 3000 mg/lg bw/d.

2

Dose descriptor:

LOAEL

Effect level:

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

Based on:

test mat.

Sex:

male

3

Dose descriptor:

NOAEL

Effect level:

340

Based on:

test mat.

Sex:

female

Basis for effect level:

other: Decreased body weight and protein casts observed in the renal tubule at 1000 mg/lg bw/d.

4

Dose descriptor:

LOAEL

Effect level:

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

Based on:

test mat.

Sex:

female

Target system / organ toxicity

Critical effects observed:

not specified

Any other information on results incl. tables

- Clinical signs: frequent vomiting and nausea were caused, which appeared to depend on the dose used.

- Body weight: all males in the high dose group, all females in the intermediate group and 2/3 females in the high dose group lost weight over the 6 month-study. Not dose-related in females.

- Food consumption: not affected by treatment except in the intermediate dose group females. Not dose-related.

- Urinalysis: no treatment-related effects.

- Hematology: no treatment-related findings.

- Biochemistry: total cholesterol and glucose decrease in blood in the high dose group. The initial cholesterol level was recovered at the end of the 6-month treatment period in both sexes (when the level had increased in other control and treated groups).

- Organ weights: the relative to body weight kidney and liver weights were slightly higher in the high dose group males than in other groups.

- Histopathology: at 1.2 and 3.6 mL/kg bw/day, protein casts were observed in the renal tubule of most animals. No remarkable treatment-related change was observed in other organs.

Table 1: Protein casts observed in the renal tubule

	Male				Female
	Control	0.4	1.2	3.6	Control	0.4	1.2	3.6
No. animals examined	3	3	3	3	3	2	3	3
Protein casts	1	1	2	3	1	2	3	3

Applicant's summary and conclusion

Conclusions:

The NOAEL in this study is 1.2 mL/kg bw/day (equivalent to 1000 mg/kg bw/day) in males and 0.4 mL/kg bw/day (equivalent to 340 mg/kg bw/day) in females on the basis of decreased body weight and protein casts observed in the renal tubule at the next dose level. Food consumption was also decreased in the intermediate dose females.

Executive summary:

Three dogs per sex and per dose group were administered d-limonene by gavage once per day for 6 months at the dose level of 0, 0.4, 1.2 or 3.6 mL/kg bw/day.

All 6 animals (males and females) from the high dose group except one female and all females in the intermediate dose group lost weight between the first and the last day of study. Food consumption only decreased in the intermediate dose group females. Urinalysis and hematology were not affected by treatment. The glucose and total cholesterol levels in blood decreased in the high dose group males and females when compared to the pre-treatment levels; the total cholesterol level recovered the pre-test level by the end of the 6-month treatment period. The relative kidney and liver weights were slightly higher in the high dose group males than in other groups. A dose-related increased incidence of protein casts were observed in the renal tubule: all males in the high dose group and all females in the intermediate and high dose groups showed this effect.