Magnesium

Toxicity to reproduction

Administrative data

Endpoint:

one-generation reproductive toxicity

Remarks:

based on test type (migrated information)

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2009

Report date:

2009

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 422 (Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test)

Deviations:

yes

Remarks:

please see 'overall remark' below

GLP compliance:

yes

Remarks:

Testing laboratory:Biotoxtech Co., Ltd.,Report № B09179

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

magnesium sulphate

IUPAC Name:

magnesium sulphate

Constituent 2

Reference substance name:

Magnesium sulphate

EC Number:

231-298-2

EC Name:

Magnesium sulphate

Cas Number:

7487-88-9

IUPAC Name:

7487-88-9

Test material form:

solid: compact

Details on test material:

- Name of test material (as cited in study report): Magnesium sulfate
- Molecular formula (if other than submission substance): MgSO4
- Molecular weight (if other than submission substance): 120.37
- Physical state: White powder
- Analytical purity: 100.2 %
- Lot/batch No.: 039K0150
- Storage condition of test material: Room temperature (16.0–27.1 degree C)
- Other: Hydrophilic
- Supplier: ALDRICH

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

[TEST ANIMALS]
- Source: ORIENTBIO INC., Korea
- Age at study initiation: Male, 9 weeks old, 311.6–344.1 g ; Female, 8 weeks old, 190.6–232.3 g
- Weight at study initiation: Male, 311.6–344.1 g ; Female, 190.6–232.3 g
- Housing: Stainless wire mesh cages, 260W×350D×210H (mm), Polycarbonate cage 260W×420L×180H (mm)
- Number of animals per cage: One animal (during pre- and post mating periods), One male and one female (during mating period), One female and pups (during lactation period)
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: approximately 7 days
[ENVIRONMENTAL CONDITIONS]
- Temperature (°C): 20.8–23.1 °C
- Humidity (%): 38.4–77.8 %
- Air changes (per hr): 10–15 clean, fresh, filtered air changes per hr
- Photoperiod (hrs dark / hrs light): 12 hour light/dark cycle

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

other: water for injection

Details on exposure:

Amount of vehicle : 5 mL/kg

Details on mating procedure:

- M/F ratio per cage: 1 to 1
- Length of cohabitation: 14 days
- Proof of pregnancy: a vaginal plug twice a day, AM and PM.
- the mating indices : 100 %
- the mating periods : 2.2 - 2.7 days

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

Male in main group and both sexes in recovery group : a total of six weeks (two weeks each prior to, during and post mating).Female in main group : two weeks prior to mating, throughout gestation and five days (six days in twelve females) after delivery

Frequency of treatment:

Once a day

Doses / concentrations

Remarks:

Doses / Concentrations:
0, 50, 150, and 450 mg/kg bw
Basis:
actual ingested

No. of animals per sex per dose:

Control : Male-13 rats(main group)+6 rats(recovery group, not mating), Female-13 rats(main group)+6 rats(recovery group, not mating)
Low dose : Male-13 rats, Female-13 rats
Mid dose : Male-13 rats, Female-13 rats
High dose : Male-13 mice(main group)+6 mice(recovery group), Female-13 mice(main group)+6 mice(recovery group)

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: In the preliminary study (Biotoxtech Study No. : B09179P), acute diarrhea was observed in animals dosed with 1000 mg/kg, and soft stool and diarrhea were observed in animals dosed with 500 mg/kg. Based on the results, 450 mg/kg was selected as the high dose level for this study and sequentially divided by a geometric ratio of 3 to produce two additional lower doses of 150 and 50 mg/kg as mid- and low dose levels. The control group received vehicle only (water for injection) at the same dose volume as the dosed groups.

Examinations

Parental animals: Observations and examinations:

CLINICAL OBSERVATIONS:
- All animals were observed once a day throughout the study on mortality, general condition and gross evidence of clinical signs and symptoms
Detailed physical examinations :
- All animals were once in pretest period, once a week throughout the dosing and recovery periods on central and autonomic nervous system effects, motor activity, and behaviour.
BODY WEIGHT: Body weight were measured just prior to dosing, once a week throughout the dosing period, and the day prior to necropsy

Litter observations:

The following parameters were examined in F1 offspring:
- Number and sex of pups
- Number of corpora lutea and uterine implants
- Mean litter size
- Live births
- Postnatal mortality
- Body weights of pups on postnatal days 0 and 4.
- External examination : All pups on delivery day and on postnatal day 4

Postmortem examinations (parental animals):

Necropsy : Yes (see table [No. 15-1 and 15-2] and appendix [No. 15-1 and 15-2]) Urinalysis : Yes (see table [No. 10-1 and 10-2] and appendix [No. 10-1 and 10-2] )
Blood biochemistry : Yes (see table [No. 11-1 and 11-2] and appendix [No. 11-1 and 11-2] ) Hematology : Yes (see table [No. 12-1 and 12-2] and appendix [No. 12-1 and 12-2] ) Histopathology : Yes (see table [No. 16-1 and 16-2] and appendix [No. 16-1 and 16-2] )

Statistics:

- The SAS program
- Bartlett's test, ANOVA, Dunnett's test, Kruskal-wallis test, Mann-whitney u-test :
the data including body weights, food consumption, mating period, gestation period, pre- and post-implantation loss rate, live birth index, viability index postnatal Day 0 and 4, traction test, rotarod test, spontaneous motor activity test, urine volume, hematology and blood biochemistry parameters and organ weights data.
- Kruskal-wallis test, Mann-whitney u-test : the data of external examinations
- Folded-F test, Aspin-Welch t-test : the data of recovery groups

Reproductive indices:

- The gestation indices : 100 %
- The pre-implantation loss rates : 10.5 % (control), 6.5 % (50 mg/kg), 7.1 % (150 mg/kg), 4.8 % (450 mg/kg)
- The post-implantation loss rates : 7.9 % (control), 6.9 % (50 mg/kg), 8.4 % (150 mg/kg), 5.5 % (450 mg/kg)

Offspring viability indices:

- The live birth indices : 92.1 % (control), 93.1 % (50 mg/kg), 91.6 %(150 mg/kg), 94.5 %(450 mg/kg)
- The viability index postnatal day 0 : 97.6 % (control), 95.6 % (50 mg/kg), 100 %(150 mg/kg), 99.0 %(450 mg/kg)

Results and discussion

Results: P0 (first parental generation)

General toxicity (P0)

Clinical signs:

effects observed, treatment-related

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

no effects observed

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Other effects:

no effects observed

Reproductive function / performance (P0)

Reproductive function: oestrous cycle:

not examined

Reproductive function: sperm measures:

not examined

Reproductive performance:

no effects observed

Details on results (P0)

CLINICAL SIGNS AND MORTALITY (PARENTAL ANIMALS) - In the main and recovery groups, all animals survived the duration of the study. There were no effects on mortality. In the main group, loss of fur in forelimb was observed in one male dosed with 50 mg/kg from Days 19–41 after dosing, and soft stool was observed in one male dosed with 150 mg/kg from Days 7 and 9 after doing. Soft stool was observed in five males dosed with 450 mg/kg on Day 1, and it was observed sporadically or frequently in totals eleven males during the study. Diarrhea was observed in one male dosed with 450 mg/kg from Day 2 after dosing. Soft stool was observed each one female (total three females) dosed with 150 mg/kg from Days 9 and 14 after dosing and Day 2 of gestation. Also, it was observed in six females dosed with 450 mg/kg on Day 1 and in total ten females until a mating period sporadically. It was observed sparsely in two females during a gestation period and was not observed during a lactation period. No effects were evident in the other dosed groups. In the recovery group, soft stool was observed in one or two animals of both sexes dosed with 450 mg/kg on Day 1 after dosing, and it was observed sporadically or frequently in total five males and in total six females during a dosing period. During a recovery period, it was observed in each one animal of both sexes on the first day of recovery.
BODY WEIGHT AND WEIGHT GAIN - In parental animals, no statistically significant differences in body weights were noted in all animals in main and recovery groups compared to the control group during the study. In pubs, statistically significant decrease in body weight was noted in male pubs in 450 mg/kg dosed group compared to the control group on postnatal Day 4. No dose-related effects were noted.
FOOD CONSUMPTION (PARENTAL ANIMALS) - Statistically significant decrease in food consumption was noted in males dosed with 150 mg/kg in main group compared to the control group on Day 7 after dosing. Statistically significant increase was noted in males dosed with 450 mg/kg in recovery group compared to the control group on the day prior to dosing (Day 0). No statistically significant differences were evident in the other dosed groups.
REPRODUCTIVE PERFORMANCE (PARENTAL ANIMALS) - In 0, 50, 150, and 450 mg/kg dosed groups, the mating periods were 2.3, 2.2, 2.9 and 2.7 days, the mating indices were 100 %, the gestation periods were 22.1, 21.9, 22.1 and
22.2 days, the fertility indices of both sexes were 92.3, 84.6, 100 and 92.3 %, respectively. There were no statistically significant differences in any dose group.
ORGAN WEIGHTS (PARENTAL ANIMALS) - In the main group, absolute organ weights of kidneys in males dosed with 50 and 150 mg/kg were statistically significantly decreased (p<0.05) compared to the control group. Relative organ weights of testes in males dosed with 150 mg/kg were statistically significantly increased (p<0.05) compared to the control group. No statistically significant differences on absolute and related organ weights were noted in females. In the recovery group, absolute and relative organ weights of males were not statistically significantly different from control, but relative organ weights of ovaries in females dosed with 450 mg/kg were statistically significantly increased (p<0.05) compared to the control group.GROSS PATHOLOGY (PARENTAL ANIMALS) - Results of the gross postmortem examinations performed on all animals in the study did not reveal any evidence of grossly visible morphologic abnormalities in all groups.
HISTOPATHOLOGY (PARENTAL ANIMALS): NON-NEOPLASTIC - The squamous cell hyperplasia of forestomach, edema of submucosa, inflammation of submucosa, focal erosion of mucosa, focal ulcer of mucosa into forestomach and hyperplasia of mucosa into cecum were evident in one female dosed with 450 mg/kg in main group. Stomach and cecum were conducted for histopathology in animals dosed with 50 and 150 mg/kg in main group and in all recovery groups. There were no abnormal findings. In addition, in the control and 450 mg/kg main groups of both sexes, focal basophilic tubules of kidneys, mineralization of corticomedullary junction, mononuclear pyelitis, bilateral lymphocytic, focal lymphocytic cell infiltration of liver, focal mononuclear cell infiltration of liver, interstital lymphocytic cell infiltration of prostate and lymphocytic depletion of cortical into thymus were spontaneously or sporadically observed. In the recovery group of both sexes, no abnormal findings were observed.
Other findings : Normal deliveries were observed in all animals.

Results: F1 generation

General toxicity (F1)

Clinical signs:

no effects observed

Mortality / viability:

no mortality observed

Body weight and weight changes:

no effects observed

Sexual maturation:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

no effects observed

Histopathological findings:

not examined

Details on results (F1)

BODY WEIGHT -The body weight of male pups on postnatal Day 4 was 10.9±1.1 g (control), 9.7±1.0 g (50 mg/kg),
10.5±1.2 g (150 mg/kg) and 9.5±1.6 g (450 mg/kg). The decrease in body weight in male pups treated with 450 mg/kg group was statistically significant (p<0.05), but no dose-related effects were noted. So, we concluded no effect on body weight of offspring. See appendix [No. 3-3].

External findings : Edema of left in hind limb was observed in one pup (0.55%) in 50 mg/kg group on postnatal Day 0, and brachyury was observed in one pup (0.62%) in 150 mg/kg group on Days 0 and 4. No effects were evident in the other dosed groups. Detailed data was suggested below.

Effect levels (F1)

Dose descriptor:

NOAEL

Generation:

F1

Effect level:

>= 450 mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: see 'Remark'

Overall reproductive toxicity

Reproductive effects observed:

not specified

Any other information on results incl. tables

 

Group	Implantation loss rate (%)		Live birth index (%)	Viability index (%)		Sex ratio (male/Female)
	Pre-	Post-		PND 0	PND 4	PND 0	PND 4
Control	10.5(+/-) 7.5	7.9(+/-)8.1	92.1(+/-)8.1	97.6(+/-)6.0	99.6(+/-)1.5	1.0 (85/82)	1.0 (85/81)
50mg/kg	6.5(+/-)6.5	6.9(+/-)7.1	93.1(+/-)7.1	95.6(+/-)7.8	97.4(+/-)6.0	1.2 (87/75)	1.2 (86/72)
150mg/kg	7.1(+/-)5.1	8.4(+/-)11.1	91.6(+/-) 11.1	100.0(+/-) 0.0	99.1(+/-)2.3	0.9 87/96)	0.9 (86/95)
450mg/kg	4.8(+/-)4.9	5.5(+/-)6.3	94.5(+/-)6.3	99.0(+/-)2.3	96.8(+/-)5.9	1.1 (99/89)	1.1 (96/86)

 

Applicant's summary and conclusion

Conclusions:

No dose-related effects were noted in reproduction function. The NOAEL was considered to be 450 mg/kg bw/day for reproduction toxicity study.