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Toxicological information

Direct observations: clinical cases, poisoning incidents and other

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Administrative data

Endpoint:
direct observations: clinical cases, poisoning incidents and other
Type of information:
migrated information: read-across based on grouping of substances (category approach)
Adequacy of study:
key study
Study period:
Not reported
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Study well documented, meets generally accepted scientific principles, acceptable for assessment
Cross-referenceopen allclose all
Reason / purpose:
reference to same study
Reason / purpose:
reference to other study

Data source

Reference
Reference Type:
publication
Title:
Unnamed
Year:
1984

Materials and methods

Study type:
study with volunteers
Endpoint addressed:
repeated dose toxicity: oral
Principles of method if other than guideline:
A clinical trial was conducted on healthy human volunteers for six weeks to evaluate the effect of the test material on immune response and plasma lipoproteins.
GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Zinc sulfate

Method

Type of population:
general
Subjects:
- Number of subjects exposed: 11
- Sex: Male
- Age: Adult
- Known diseases: None
- Other: Subjects were instructed not to change dietary intake or exercise during the study period
Ethical approval:
not specified
Route of exposure:
oral
Reason of exposure:
intentional
Exposure assessment:
measured
Details on exposure:
Clinical trial: 150 mg Zn (as ZnSO4) was administered to healthy volunteers twice a day for six weeks.
Examinations:
- Haematology: Total number of lymphocytes and function, T and B cells, polymorphonuclear (PMN) leukocyte function, phagocytosis and bactericidal capacity
- Estimation of plasma lipoproteins: Total cholesterol, triglyceride, HDL & LDL-cholesterol
- Estimation of plasma Zn levels by atomic absorption spectrophotometry
Medical treatment:
No

Results and discussion

Clinical signs:
No side effects
Results of examinations:
PLASMA LIPOPROTEINS:
- HDL-cholesterol: Decreased from 42 to 29 mg/dL;
- LDL-cholesterol: Increased from 110 to 127 mg/dL;
- LDL/HDL ratio (atherogenic index): Increased from 2.6 to 4.2
- Total cholesterol and triglyceride levels: No significant change

PLASMA ZINC LEVELS: Increased from 83 to 199 µg/dL

HAEMATOLOGY:
Total lymphocytes count, T and B cells, and T-lymphocyte subsets: No significant change

IMMUNE RESPONSE:
- Polymorphonuclear(PMN) migration response to chemotactic migration: Decreased (292 ± 57 PMN/10 high-power field) during the period of Zinc administration and increased (576 ± 114 PMN/10 high-power field) to baseline values (632 ± 101 PMN/10 high-power field) several weeks after stopping the supplements
- Phagocytosis of opsonized bacteria: Impaired
- Bactericidal capacity: Slightly reduced but not significant

For details see the following tables in the attached PDF:
Table 1: Plasma Zinc Levels and Polymorphonuclear (PMN) Leukocyte Function
Table 2: Lymphocyte Number
Table 3: Serum Lipid and Lipoprotein Concentrations
Effectivity of medical treatment:
Not applicable
Outcome of incidence:
Not applicable

Any other information on results incl. tables

None

Applicant's summary and conclusion

Conclusions:
Under the test conditions, moderately large amount of oral Zinc supplement was observed to be associated with significant impairment of lymphocyte and polymorphonuclear functions.
Executive summary:

A clinical trial was conducted on 14 healthy human volunteers for six weeks to evaluate the effect of the test material (150 mg Zn as ZnSO4, twice a day for six weeks) on immune response and plasma lipoproteins.

 

A reduction in lymphocyte stimulation response to phyto-hemagglutinin as well as chemotaxis and phagocytosis of bacteria by polymorphonuclear leukocytes was observed. Serum high-density lipoprotein concentration decreased significantly and low-density lipoprotein level increased slightly.

 

Under the test conditions, moderately large amount of oral Zinc supplement was observed to be associated with significant impairment of lymphocyte and polymorphonuclear functions.