2,6,10,15,19,23-hexamethyltetracosa-2,6,10,14,18,22-hexaene

Repeated dose toxicity: oral

Administrative data

Endpoint:

sub-chronic toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1926

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Good publication

Data source

Reference

Reference Type:

publication

Title:

EXPERIMENTS WITH THE UNSATURATED HYDROCARBON, SQUALENE (SPINACENE).

Author:

Channon J.

Year:

1926

Bibliographic source:

From the Departments of Physiology and Biochemistry, University College, London.

Materials and methods

Test guideline

Qualifier:

no guideline followed

Deviations:

not applicable

Principles of method if other than guideline:

The general plan of the experiment was to feed two groups of rats on a complete artificial diet, while one group received in addition a small quantity
of squalene each day for 42 days

GLP compliance:

no

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

2,6,10,15,19,23-hexamethyltetracosa-2,6,10,14,18,22-hexaene

EC Number:

203-826-1

EC Name:

2,6,10,15,19,23-hexamethyltetracosa-2,6,10,14,18,22-hexaene

Cas Number:

111-02-4

Molecular formula:

C30H50

IUPAC Name:

2,6,10,15,19,23-hexamethyltetracosa-2,6,10,14,18,22-hexaene

Test material form:

other: liquid

Details on test material:

- Name of test material: squalene
- Substance type:organic
- Physical state:liquid
- Analytical purity:no data

Test animals

Species:

rat

Strain:

not specified

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Diet: complete artificial diet that described by Drummond and Coward [1920].

Administration / exposure

Route of administration:

other: dropped directly into their mouths from a micro-burette.

Vehicle:

not specified

Duration of treatment / exposure:

dropped directly in mouths from a micro-burette.

Frequency of treatment:

daily

Doses / concentrations

Remarks:

Doses / Concentrations:
660 mg
Basis:
actual ingested

No. of animals per sex per dose:

test group: 10 rats
negative control: 9 rats

Control animals:

yes, concurrent no treatment

Examinations

Observations and examinations performed and frequency:

Treatment of livers:
At the end of the experiment the animals were killed by chloroform and their livers removed as free from blood as possible.

Treatment of faeces:
The faeces were stored in alcohol.

Other examinations:

The faeces were collected throughout the experiment at weekly intervals and stored in alcohol.

Results and discussion

Results of examinations

Clinical signs:

no effects observed

Mortality:

no mortality observed

Body weight and weight changes:

effects observed, treatment-related

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

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Gross pathological findings:

not examined

Histopathological findings: non-neoplastic:

not examined

Histopathological findings: neoplastic:

not examined

Details on results:

OTHER FINDINGS

It is clear from the weight of unsaponifiable matter from the faeces of the latter animals, and from its iodine value, that much of the squalene administered has been excreted.

Effect levels

Dose descriptor:

NOAEL

Effect level:

ca. 660 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: body weight; amounts of cholesterol,

Target system / organ toxicity

Critical effects observed:

not specified

Any other information on results incl. tables

If we assume that that fraction of this unsaponifiable matter which is not squalene has an iodine value which is the same as that of the material from the control group, namely 80.4%, then we may calculate from the iodine value of the whole of this unsaponifiable matter (316), that the amount of squalene present is 81.41 %, i.e. 16 -79 g. (squalene has iodine value 371). This figure can only be approximate, but some rough check on it is obtained from the fact that, if we subtract the weight of material not sterol in the faeces of the control group from the corresponding figure for the faeces of the animals receiving squalene, we arrive at the figure 17-60 g. These figures 16.79 and 17.60 g. can only be approximate, but they would seem to show that about 17 g. of the 27.7 g. of squalene administered had been excreted. Thus about 10 g. have been absorbed during the course of 42 days and this absorption has resulted in a marked increase in the weight of unsaponifiable matter in the livers and also in the bodies of these animals, namely, from 0.3680 to 1.0774 g. in the case of the livers and from 1.8620 to 2 .9114 g. in that of the bodies. There is also a large increase in the amounts of cholesterol, from 0.2576 to 0.6189 g. in the livers and from 1.3000 to 2.1620 g. in the bodies.

No obvious ill effects followed the administration of squalene and post mortem examination showed that the organs of the animals were very healthy. There appeared to be a greater deposition of fat in the animals which received squalene and on the whole they seemed to grow at a somewhat greater rate than those of the control groups, possibly because the laxative action of the squalene caused a greater food consumption.

Applicant's summary and conclusion

Conclusions:

The experiment shows that when squalene is administered to the rat, it is in part absorbed and as a result of absorption there is a marked increase in the amounts of unsaponifiable matter and of cholesterol in the body and liver of the animal. No effect up to the dose of 3300 mg/Kg bw has been reported.

Executive summary:

Squalene has been tested in subchronic repeted study by oral administration. The general plan of the experiment was to feed two groups of rats on a complete artificial diet, while one group received in addition a small quantity of squalene each day. Immediately before feeding-time the animals were given approximately 660 mg of squalene dropped directly into their mouths from a micro-burette. Records were taken of the amount of squalene given each day. The faeces were collected throughout the experiment at weekly intervals and stored in alcohol. At the end of the experiment the animals were killed by chloroform and their livers removed as free from blood as possible. The experiment shows that when squalene is administered to the rat, it is in part absorbed and as a result of absorption there is a marked increase in the amounts of unsaponifiable matter and of cholesterol in the body and liver of the animal.