Registration Dossier

Administrative data

Endpoint:
sub-chronic toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Study period:
10/1990-12/11/1990
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
comparable to guideline study

Data source

Reference
Reference Type:
publication
Title:
Unnamed
Year:
1991
Report Date:
2011

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 407 (Repeated Dose 28-Day Oral Toxicity in Rodents)
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
impurity
Specific details on test material used for the study:
Erythritol, Lot number 90006-138
Upon arrival, the test substance was stored in the dark, at room temperature, in the original plastic bottles

Test animals

Species:
rat
Strain:
Wistar
Details on species / strain selection:
outbred (Hsd/Cpb:WU) rats, derived from a specific-pathogen free (SPF) colony
Sex:
male/female
Details on test animals and environmental conditions:
Initial body weights: males: 91.4-92.2 g; females: 81.5-82.3 g
diet: CIVO cereal-based stock : (75% are defatted soybean meal, whole ground wheat, and whole ground corn. The diet contained balanced amounts of vitamins and minerals.)

From their arrival until the end of the study he rats were housed in groups of five in suspended stainless steel cages, fitted with wire-screen bottoms and fronts.
Animals were acclimatized for 6 days
Temperature room : 22.5°C-26°C
Relative humidity : 50-75%
Ventilation rate : 15 air changes per hour
Light : artificial, 12h per day

Administration / exposure

Route of administration:
oral: feed
Details on route of administration:
Erythritol mixed into the diet
Vehicle:
unchanged (no vehicle)
Details on oral exposure:
Erythritol mixed into the diet at 0 (control), 5, or 10% at the expense of dietary starch; food and water available ad libitum; homogeneity, stability, and nominal concentrations over test period confirmed -28 days

Food intake was estimated by weighing the feeders twice weekly. Fresh food was supplied twice weekly. Tap water was supplied in glass bottles, which were refilled daily with fresh water. Weekly water consumption was estimated by daily weighing of the bottles.
Analytical verification of doses or concentrations:
not specified
Details on analytical verification of doses or concentrations:
Not specified
Duration of treatment / exposure:
28 days
Frequency of treatment:
At each meal, food and water available ad libitum
Doses / concentrationsopen allclose all
Dose / conc.:
0 mg/kg bw/day (nominal)
Remarks:
0% in the publication
Dose / conc.:
1 700 mg/kg bw/day (nominal)
Remarks:
5% at the expense of dietary starch in the publication (corresponding to 1.7 g/kg bw in a similar diet study in rats referenced in SCF, 2003)
Dose / conc.:
3 800 mg/kg bw/day (nominal)
Remarks:
10% at the expense of dietary starch in the publication (corresponding to 3.8 g/kg bw in a similar diet study in rats referenced in SCF, 2003)
No. of animals per sex per dose:
10 rats/sex/dose then 60 rats
Control animals:
yes
Details on study design:
Not specified
Positive control:
Not specified

Examinations

Observations and examinations performed and frequency:
signs for ill health : twice daily observation, once daily on weekends
body weights : recorded 3 days prior to and at study initiation and weekly there after food/water consumption, food utilization efficiency, and test substance intake determined weekly
Sacrifice and pathology:
- haematology. blood samples collected on day 25 and included PCV, Hb, RBC, red blood tell distribution width (RDW-SD), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), white blood tell count (WBC), dilferential white blood tell count, prothrombin time (PII), thrombocyte count, activated partial thromboplastin time (APTT), mean platelet volume (MPV) and platelet distribution width (PDW)

- clinicat chemistry. samples collected on days 27 and 28 (except glucose: day 25) and included: glucose, alkaline phosphatase (ALP), aspartate aminotransferase (ASAT), alanine aminotransferase (ALAT), gamma glutamyl transferase (GGT), total protein, albumin, globulin, protein electrophoresis, ratio of albumin to globulin, urea, creatinine, total bilirubin, Na, K, Ca, Cl, inorganic phosphate, cholesterol, triglycerides, and phospholipids

- urinalysis: samples collected on day 25 and included: appearance, pH, glucose, occult blood, ketones, protein, bilirubin, urobilinogen, sediment, volume, density, Na, K, Cl, Ca, and citrate

- organ weight determinations were made at terminal necropsy for the adrenals, brain, caecum (full and empty) heart, kidneys, liver, lungs, ovaries, pituitary, prostate, seminal vesicles, spleen, sublingual salivary glands, submaxillary salivary glands, testes, thymus, thyroid, and uterus

- pathology : gross examinations and histopathology performed on the adrenals, aorta, axillary lymph nodes, brain, caecum, colon, exorbital lachrymal glands, eyes, femur, Harderian glands, heart, kidneys, liver, lungs, mammary gland, mesenteric lymph node, esophagus, ovaries, pancreas, pituitary, prostate, rectum, sciatic nerve, seminal vesicles, skin, smalt intestine, spinal cord, sternum, stomach, sublingual salivary glands, submaxillary salivary glands, testes, thymus, thvroid with parathyroids, trachea and bronchi, uterus, vagina, and any other gross lesions.
Other examinations:
- ophthalmology. examinations of all rats prior to treatment and at the end of the study
Statistics:
body weight data analysed using one way analysis of co-variance and Dunnett's multiple comparison tests; haematological, clinical chemistry, volume and density of urine, electrolytes in the urine and organ weights analysed using ANOVA and Dunnett's multiple comparison tests. Food and water intake and food efficiency were evaluated by analysis of variance followed by least significant difference tests. Histopathologicat findings were evaluated by the Fischer exact test.

Results and discussion

Results of examinations

Clinical signs:
effects observed, non-treatment-related
Description (incidence and severity):
Early in the study, soft stools and diarrhoea were observed in rats fed digits containing 10% erythritol and in some of the 5% dose level females. These effects disappeared as the study progressed, indicating adaptation.
Mortality:
no mortality observed
Body weight and weight changes:
effects observed, treatment-related
Description (incidence and severity):
Females: no change;
Males fed the 10% level showed a significant reduction in mean body weight. Coincident with decreased body weights were decreased food intake in high-dose males during the first 2 weeks and relatively lower food efficiency in these animais.
Food consumption and compound intake (if feeding study):
effects observed, treatment-related
Description (incidence and severity):
Females: no change;
Males fed the 10% level showed a significant reduction in mean body weight. Coincident with decreased body weights were decreased food intake in high-dose males during the first 2 weeks and relatively lower food efficiency in these animais.
Food efficiency:
effects observed, treatment-related
Description (incidence and severity):
Male : Coincident with decreased body weights were decreased food intake in high-dose males during the first 2 weeks and relatively lower food efficiency in these animais.
Water consumption and compound intake (if drinking water study):
effects observed, treatment-related
Description (incidence and severity):
Water intake was statistically increased in both sexes at the high-dose, with lesser increases noted in the low-dose males.
Ophthalmological findings:
no effects observed
Description (incidence and severity):
No changes
Haematological findings:
no effects observed
Description (incidence and severity):
No treatment-related changes in red blood tell variables. Prothrombin lime was slighlly increased and neutrophil count slightty decreased in the high-dose females.
Clinical biochemistry findings:
effects observed, treatment-related
Description (incidence and severity):
ALP activity increased in high dose animais; slightly decreased plasma albumin and ASAT activity in treated females; decreased plasma globulin 5-1 in treated males; decreased plasma globulin a-2 in low dose females; decreased plasma creatinine level in males and chloride levels in high-dose females.
Urinalysis findings:
no effects observed
Description (incidence and severity):
No indication of impaired renal function. Urine density was slightly increased in high-dose males. Na and K concentrations in females treated at both dose levels were slightly lower than controls, but total urinary excretion of these electrolytes was not significantly different over a 16-hour period.
Behaviour (functional findings):
no effects observed
Description (incidence and severity):
No changes in appearance or behaviour reported.
Immunological findings:
not examined
Organ weight findings including organ / body weight ratios:
effects observed, treatment-related
Description (incidence and severity):
lncreased absolute and relative weights of the caecum, both full and empty, in both test groups of both sexes. This effect did not always reach the point of statistical significance. Absolute and relative weights of the kidneys were increased in males al both dose levels. In treated males, absolute heart weights were decreased white in low-dose females absolute heart weights were slightly increased. Also in treated females, both absolute and relative spleen weights were slightly increased compared to the controls.
Gross pathological findings:
no effects observed
Description (incidence and severity):
The only grossly visible change in the treated animais was an enlarged caecum in one of the top dose males. No histopathological changes, including in the caecum, were found which could be attributed to erythritol treatment.
Neuropathological findings:
not examined
Histopathological findings: non-neoplastic:
not examined
Histopathological findings: neoplastic:
not examined
Other effects:
not examined
Details on results:
Not specified

Effect levels

Key result
Dose descriptor:
conc. level:
Remarks:
10% in diet
Effect level:
>= 3 800 mg/kg bw/day (nominal)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
clinical signs
body weight and weight gain
food consumption and compound intake
food efficiency
water consumption and compound intake
urinalysis
behaviour (functional findings)
gross pathology
Remarks on result:
not determinable due to absence of adverse toxic effects
Remarks:
several adaptative changes observed but no signs of toxicity

Target system / organ toxicity

Key result
Critical effects observed:
no
Lowest effective dose / conc.:
3 800 mg/kg bw/day (nominal)
System:
gastrointestinal tract
Organ:
kidney
heart
spleen
other: caecum

Applicant's summary and conclusion

Conclusions:
- Increased caecal weights, both full and empty, were generally ascribed to the presence of increased amounts of osmotically active substances (Le., erythritol and short-chain fatty acids resulting from microbial fermentation of any erythritol which was not absorbed in the small intestine) in the large intestine. This finding was considered an adaptive effect as no histopathological correlates were found.
- The increased ALP activity also was ascribed to changes associated with caecal enlargement as the intestine is considered to be the main source of this enzyme in non-fasting rats. Also, other substances which produce an increased osmotic load in the large intestine, including other polyols and slowly digested carbohydrates, have been shown to increase ALP in association with caecal enlargement.
- The increase in kidney weights in the males was not accompanied by impaired renal function as measured by urinalysis parameters or by gross and histopathological examinatns. The rapid absorption and excretion of erythritol is known to induce a diuretic effect, resulting in an increased workload on the kidneys. The increased kidney weights were therefore considered to be an adaptive rather than a toxicological effect. This also is evidenced by the increased water consumption in high-dose animais.
- Changes in absolute and//or relative heart and spleen weights in some of the erythritol-treated animais were of a minor nature and were not accompanied by any histopathological changes. As a result, these changes were not considered to be of toxicological significance.

Based on an analysis of the results obtained, the study authors concluded that the feeding of erythritol at a dietary levet of 10% did not result in overt signs of toxicity, although several adaptive changes were observed


Executive summary:

In a diet study in 60 rats (protocol equivalent to OECD 407), the authors concluded that the feeding of erythritol at a dietary levet of 10% did not result in overt signs of toxicity, although several adaptive changes were observed