Bis(D-gluconato-O1,O2)zinc

Repeated dose toxicity: other routes

Administrative data

Endpoint:

short-term repeated dose toxicity: other route

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2008

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

2008

Report date:

2008

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

- Principle of test: The aim of the study was to determine the maximal iterative dose of zinc that can be administrated in rats without any adverse effect.
- Short description of test conditions: Saline (control group) or zinc gluconate at 1, 2 or 4 mg/kg were intraperitoneally injected in animals daily during 7 days.
- Parameters analysed / observed: The tolerance of zinc treatments was evaluated by the observation of clinical symptoms, haematological parameters and biochemistry, in relation to the zinc and copper levels in blood, liver, pancreas and faeces.

GLP compliance:

not specified

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Bis(D-gluconato-O1,O2)zinc

EC Number:

224-736-9

EC Name:

Bis(D-gluconato-O1,O2)zinc

Cas Number:

4468-02-4

Molecular formula:

C12H22O14Zn

IUPAC Name:

bis(D-gluconato-O1,O2)zinc

Test material form:

solid: particulate/powder

Details on test material:

- Appearance : White cristalline powder:
- Batch number: 1700001575
- Manufacturing date: 10.08.2017
- Expiry date: 09.08.2020

Test animals

Species:

rat

Strain:

Wistar

Sex:

male

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: purchased from Charles River Laboratories (Les Oncins, France)
- Weight at study initiation: weighing about 250 g
- Housing: Rats were housed according to the Agriculture and Environment Ministry standards
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: 1 week before the initiation of the treatment

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21±1°C
- Humidity (%): relative humidity of 55%
- Photoperiod (hrs dark / hrs light): 12-hr dark:light cycle

Administration / exposure

Route of administration:

intraperitoneal

Vehicle:

other: saline intraperitoneal composition.

Duration of treatment / exposure:

Saline or zinc gluconate were administered intraperitoneally during 7 days.

Frequency of treatment:

Saline or zinc gluconate were administered intraperitoneally every 24 hr.

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

1 mg/kg bw/day (nominal)

Remarks:

intraperitoneally

Doses / concentrations 2

Dose / conc.:

2 mg/kg bw/day (nominal)

Remarks:

intraperitoneally

Doses / concentrations 3

Dose / conc.:

4 mg/kg bw/day (nominal)

Remarks:

intraperitoneally

No. of animals per sex per dose:

20 animals divided into four groups of rats: one normal control group (saline received) and three zinc groups treated by 1, 2 and 4 mg/kg per day of zinc gluconate.

Control animals:

yes, concurrent no treatment

Details on study design:

- Dose selection rationale: based on existing litterature (presented in the publication)
- Rationale for animal assignment: 20 animals were randomly divided into four groups of rats

Examinations

Observations and examinations performed and frequency:

BODY WEIGHT: Yes
- Time schedule for examinations: every days

HAEMATOLOGY: Yes
- Time schedule for collection of blood: At the end of the study, on day 7, blood was collected
- How many animals: all animals (20)

Sacrifice and pathology:

At the end of the study, on day 7 (immediately after blood collection), the animals were killed by section of major chest vessels before tissue sampling. The liver and the pancreas were removed, weighed, immediately frozen in liquid nitrogen and stored at −80°C until analysis.

Other examinations:

Biochemical assays:
The levels of following parameteres were determined: plasma aspartate aminotransferase (AST), alanine aminotransferase (ALT), cholesterol, creatine kinase (CK), creatinine, glycaemia, lactate dehydrogenase (LDH), alkaline phosphatase (ALP) and urea.

Zinc and copper analysis:
Zinc and copper concentrations in erythrocyte, plasma, liver, pancreas and faeces were determined.

Blood elements:
White blood cells, red blood cells, blood platelets, haematocrit and haemoglobin were determined.

All these parameters were determined at the end of study (on day 7).

Statistics:

Results are expressed as means for five animals per group ± S.E.M. The global course of each parameter was evaluated by an anova on ranks (Kruskall–Wallis test), and then the comparison between the four groups were performed with nonparametric rank sum tests (Mann–Whitney tests) using Statistica software (StatSoft Inc., Tulsa, OK, USA). Significance was considered at the level of P < 0.05.

Results and discussion

Results of examinations

Clinical signs:

not specified

Mortality:

no mortality observed

Body weight and weight changes:

effects observed, non-treatment-related

Description (incidence and severity):

From the second day, we observed a significant weight gain for the rats of control and 1 mg/kg zinc groups, whereas no weight gain was observed in the two other groups during the whole study.

Food consumption and compound intake (if feeding study):

not specified

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

Behaviour (functional findings):

not specified

Immunological findings:

not specified

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

Only for the highest zinc dose (4 mg/kg), the autopsy of the rats showed abnormal, abdominal organs on day 7 of the study, with the outcome of a congestive peritonitis and the thickening of the hepatic lobe borders.

Gross pathological findings:

not specified

Neuropathological findings:

not specified

Histopathological findings: non-neoplastic:

no effects observed

Histopathological findings: neoplastic:

no effects observed

Other effects:

no effects observed

Details on results:

Copper levels of zinc in faeces:
A dose-dependent excretion of zinc was observed on and after the fourth day of zinc supplementation. Concerning copper levels in faeces, no significant differences were observed between the control and the zinc-treated groups for the whole study.

Blood constituents:
For doses under 4 mg/kg, no significant effects of zinc on white and red blood cells as well as haematocrit and haemoglobin were observed between the control and the zinc groups. Significantly higher platelet levels were observed after injections with 2 mg/kg of zinc.

Biochemical parameters:
There were very few significant differences between the zinc groups and the normal control group. Only a significant hypoglycaemia (11% decrease) was observed after injection of 4 mg/kg of zinc compared to the
control group (P < 0.05).

Effect levels

Dose descriptor:

NOAEL

Effect level:

2 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male

Target system / organ toxicity

Critical effects observed:

no

Applicant's summary and conclusion

Conclusions:

No serious adverse effect was found within 1 week in rats injected intraperitoneally with 2 mg/kg/day of zinc gluconate. Results at 4 mg/kg/day of zinc gluconate should be used with a cautious manner.

Executive summary:

Although zinc is an essential trace element involved in many physiological functions, toxicological data concerning acute exposure are scarce. The aim of our study was to determine the maximal iterative dose of zinc that can be administrated in rats without any adverse effect. Saline (control group) or zinc gluconate at 1, 2 or 4 mg/kg were intraperitoneally injected in animals daily during 7 days. The tolerance of zinc treatments was evaluated by the observation of clinical symptoms, haematological parameters and biochemistry, in relation to the zinc and copper levels in blood, liver, pancreas and faeces. We found no serious adverse effect within 1 week in rats injected intraperitoneally with 1 or 2 mg/kg/day of zinc gluconate, which tends to indicate that those doses could be useful in future therapeutic research. During the treatment of adult rats with repeated intraperitoneal injections of a 4 mg/kg/day zinc dose it was observed the occurrence of clinical adverse effects within a few days, as intraperitoneal local intolerance and effect on the body weight of rats. They are considered as minor effects and are used in a cautious manner.