[No public or meaningful name is available]

Toxicity to reproduction

Administrative data

Endpoint:

two-generation reproductive toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2000

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Data source

Reference

Reference Type:

publication

Title:

Developmental Effects and Health Aspects of Soy Protein Isolate, Casein, and Whey in Male and Female Rats

Author:

T. M. Badger, M. J. J. Ronis, and R. Hakkak

Year:

2001

Bibliographic source:

International Journal of Toxicology, 20:165–174, 2001

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

Adult breeder male and female Sprague-Dawley rats were were randomly assigned to one of three groups and fed one of
three semipurifed diets. Animals were allowed to breed and the offspring were weaned to the same diet as their dams. At
approximately 90 days of age, offspring from different parents within a diet group were mated to produce the F2 generation.
Offspring from both F1 and F2 generations were fed their respective diets throughout their entire lives.
Rats were fed AIN-G93 diets made with either casein protein (CAS), soy protein isolate (SPI), or whey protein hydrolysate (WPH) and bred. The birth weight, weight gains, body length, anogenital distance, and age of puberty (vaginal opening or preputial gland separation) of the F1 generation were measured. The F2 rats were euthanized and their organ weight was measured.
The breeding success (percent of males and females that produced offspring after mating) of the F1 generation, litter size, and percent of female offspring were investigated for three breeding sessions (at ages 90, 180, and 270 days).

GLP compliance:

not specified

Remarks:

published study

Test material

Test material information

Constituent 1

Reference substance name:

whey protein hydrolysate

IUPAC Name:

whey protein hydrolysate

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Administration / exposure

Route of administration:

oral: feed

Vehicle:

unchanged (no vehicle)

Details on exposure:

All diets were made according to the AIN-93G diet formula (Reeves, Nielsen, and Fahey, 1993), except that corn oil replaced soy oil and the protein source was either CAS,WPH, or SPI. Amino acids were added to each diet to equalize the essential amino acids among diets.

Frequency of treatment:

The tested substance was incorporated to the diet and thus fed daili.

Details on study schedule:

At approximately 90 days of age, offspring from different parents within a diet group were mated to produce the F2 generation.

Doses / concentrations

Dose / conc.:

200 000 mg/kg diet

Control animals:

yes, plain diet

Examinations

Postmortem examinations (offspring):

body weights when examined in a separate set of rats at approximately age 55 days

Statistics:

Diet group was modeled as a between animals effect and day as a within animal effect. Organ weight and testosterone metabolism data were analyzed by one-way analysis of variance followed by Bonferroni post hoc analysis as described previously (Fisher and van Belle 1993).
Statistical signi cance was set at p < .05, and all p values are not adjusted for multiple comparisons.

Results and discussion

Results: P0 (first parental generation)

General toxicity (P0)

Clinical signs:

no effects observed

Dermal irritation (if dermal study):

not examined

Mortality:

no mortality observed

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

no effects observed

Food efficiency:

not specified

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

not examined

Ophthalmological findings:

not specified

Haematological findings:

not specified

Clinical biochemistry findings:

not specified

Endocrine findings:

not examined

Urinalysis findings:

not examined

Behaviour (functional findings):

no effects observed

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Histopathological findings: non-neoplastic:

not examined

Histopathological findings: neoplastic:

not examined

Other effects:

no effects observed

Reproductive function / performance (P0)

Reproductive function: oestrous cycle:

no effects observed

Reproductive function: sperm measures:

no effects observed

Reproductive performance:

no effects observed

Effect levels (P0)

Key result

Dose descriptor:

NOAEL

Effect level:

> 200 000 mg/kg diet

Sex:

male/female

Basis for effect level:

reproductive performance

Remarks on result:

not determinable due to absence of adverse toxic effects

Results: F1 generation

General toxicity (F1)

Clinical signs:

no effects observed

Dermal irritation (if dermal study):

not examined

Mortality / viability:

no mortality observed

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Slightly smaller offspring were observed in the WPH group.
Body weights of male rats fed SPI and WPH were similar to each other; and were slightly less than that of CAS-fed rats. Body weights started to diverge from those of CAS-fed pups prior to weaning; and became significantly lower than CAS-fed rats at age 7 weeks (p < .05). After age 7 weeks, body weight gains of SPI- and WPH-fed rats were approximately equal or slightly greater than CAS-fed rats, and by age 18 weeks all groups were statistically the same for body weights. Similar effects were observed in female rats, except that SPI-fed females did not begin to diverge from CAS-fed rats until 7 weeks, and by 9 weeks of age, the body weights of SPI- and WPH-fed rats did not differ significantly, but were less than (p < .05) CAS-fed rats. Thereafter, the body weight gains were approximately equal.

Food consumption and compound intake (if feeding study):

no effects observed

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:

effects observed, treatment-related

Description (incidence and severity):

Male offspring fed CAS or SPI did not differ on the mean age of puberty (preputial gland separation), but WPH-fed offspring had puberty 2.0 days later ( p <.05) than CAS controls.
The mean age of puberty in female offspring (age of vaginal opening) was 2.0 days earlier ( p < .05) in the SPI-fed rats than the CAS group and the 1.3 days later ( p < .05) in the WPH group than the CAS group. The effects of diet on puberty were not affected by correction for gestational age.

Organ weight findings including organ / body weight ratios:

no effects observed

Other effects:

no effects observed

Developmental neurotoxicity (F1)

Behaviour (functional findings):

not specified

Developmental immunotoxicity (F1)

Developmental immunotoxicity:

not specified

Details on results (F1)

WHP-fed male rats had delayed puberty (1.3 days) compared with CAS-fed rats as measured by preputial gland separation.
The breeding success of F1 rats and male/female ratios were not affected by diet.

Effect levels (F1)

Key result

Dose descriptor:

NOAEL

Generation:

F1

Effect level:

> 200 000 mg/kg diet

Sex:

male/female

Remarks on result:

not determinable due to absence of adverse toxic effects

Results: F2 generation

General toxicity (F2)

Clinical signs:

no effects observed

Dermal irritation (if dermal study):

not examined

Mortality / viability:

no mortality observed

Body weight and weight changes:

no effects observed

Effect levels (F2)

Key result

Dose descriptor:

NOAEL

Generation:

F2

Effect level:

> 200 000 mg/kg diet

Sex:

male/female

Remarks on result:

not determinable due to absence of adverse toxic effects

Overall reproductive toxicity

Key result

Reproductive effects observed:

no

Applicant's summary and conclusion

Conclusions:

Rats fed either CAS, SPI, or WPH did not differ in breeding success rate and body size of offspring (birth weight and length).

Executive summary:

Not classified as toxic for reproduction