Acetylglucosaminidase, β-

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Study period:

June 04 - August 13, 2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Read-across to xylanase is applied. Data on xylanase are considered also to be valid for beta-N-acetylhexosaminidase, because both enzymes belong to the same enzyme sub-subclass IUB 3.2.1 and are considered to have a similar toxicological profile also with regard to acute toxicity.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2015

Report date:

2015

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)

Version / remarks:

Adopted 2001

Deviations:

no

GLP compliance:

yes

Test type:

acute toxic class method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Xylanase, endo-1,4-

EC Number:

232-800-2

EC Name:

Xylanase, endo-1,4-

Cas Number:

9025-57-4

Molecular formula:

Not applicable, see remarks.

IUPAC Name:

endo-1,4-beta-xylanase

Constituent 2

Reference substance name:

Protein as a constituent of enzyme deriving from the fermentation or extraction process

Molecular formula:

Not available

IUPAC Name:

Protein as a constituent of enzyme deriving from the fermentation or extraction process

Constituent 3

Reference substance name:

Inorganic salts as a constituent of enzyme deriving from the fermentation or extraction process

Molecular formula:

Not available.

IUPAC Name:

Inorganic salts as a constituent of enzyme deriving from the fermentation or extraction process

Constituent 4

Reference substance name:

Carbohydrates constituent of enzyme deriving from the fermentation or extraction process

Molecular formula:

Not available.

IUPAC Name:

Carbohydrates constituent of enzyme deriving from the fermentation or extraction process

Constituent 5

Reference substance name:

Lipids as a constituent of enzyme deriving from the fermentation or extraction process

Molecular formula:

Not available.

IUPAC Name:

Lipids as a constituent of enzyme deriving from the fermentation or extraction process

Test material form:

liquid

Details on test material:

- Lot/batch No.: PPQ33502
- Expiration date of the lot/batch: 28 February 2022

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: In-house bred animals
- Females (if applicable) nulliparous and non-pregnant: yes
- Age at study initiation: 10 weeks
- Weight at study initiation: 189.64 - 203.03 g
- Fasting period before study: The animals were not fasted prior to dose administration
- Housing: Three animals were housed in a standard Polysulfone cage (size: L 430 x B 285 x H; 200 mm) with stainless steel mesh top grill. Clean sterilized paddy husk was provided as bedding material. Sterilized paper shreds were provided as nesting material for enrichment.
- Diet (e.g. ad libitum): Nutrilab rodent feed (Manufactured by Provimi Animal Nutrition India Pvt Ltd.) ad libitum
- Water (e.g. ad libitum): Ad libitum
- Acclimation period: 7-9 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19.6 to 22.4°C
- Humidity (%): 50 to 64%
- Air changes (per hr): 12 to 15 air changes per hour
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 22 June 2015 To: 15 July 2015

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

unchanged (no vehicle)

Details on oral exposure:

Undiluted test material

Doses:

The animals were given two dosages of 10.3 mL/kg body weight with an interval of 4 hours between each administration (equivalent to 2536 mg enzyme concentrate dry matter/kg bodyweight or 652 mg aep/kg bodyweight)

No. of animals per sex per dose:

6

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Observation for clinical signs of toxicity and mortality at 30 to 40 min, 1 hr (±10 min), 2 hrs (±10 min), 3 hrs (±10 min) and 4 hrs (±10 min) after each administration on Day 1 and thereafter, once daily for clinical signs of toxicity and twice daily for mortality during the 14 days observation period. Individual animal body weight was recorded on Day 1 (before test item administration for first time), Day 7 and Day 14 during the observation period.
- Necropsy of survivors performed: yes

Statistics:

No

Results and discussion

Effect levels

Effect levels 1

Sex:

female

Dose descriptor:

other: Fixed dose method - no effects were seen

Effect level:

> 20.6 mL/kg bw

Based on:

test mat.

Effect levels 2

Key result

Sex:

female

Dose descriptor:

other: Fixed dose method - no effects were seen

Effect level:

> 2 536 mg/kg bw

Based on:

other: Enzyme concentrate dry matter

Mortality:

No animals died during the study.

Clinical signs:

No clinical signs of toxicity and mortality were observed during the 14 days observation period.

Body weight:

No effect was observed on the body weights.

Gross pathology:

Effects on organs:
No gross pathological changes observed

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

No signs of toxicity were observed among the rats treated with a single oral dose of 2536 mg enzyme concentrate dry matter/kg (equivalent to 652 mg aep/kg body weight), which was the highest possible dose at dose volume 20.6 mL/kg, using the undiluted test item.

Executive summary:

The objective of this study was to assess the acute toxicity of Xylanase when administered as a single oral dose to six rats followed by an observation period of 14 days. The purpose of the study was to satisfy regulatory demands because the enzyme is used for production of food in China.

The study was conducted in accordance with the OECD Guideline No 423, “Acute Oral Toxicity – Acute Toxic Class method”. The design of the limit test was used. The test item was supplied as a brown liquid ready to use. The dose volume administered was 20.6 mL/kg body weight corresponding 2536 mg enzyme concentrate dry matter/kg body weight or 652 mg aep/kg body weight.

No mortality or clinical signs were observed after treatment and the overall body weight gain during the study was considered to be normal. The necropsy revealed no abnormalities.

In conclusion, no signs of toxicity were observed among the rats treated with a single oral dose of 2536 mg enzyme concentrate dry matter/kg bodyweight, which was the highest possible dose at dose volume 20.6 mL/kg, using the undiluted test item.