Theobromine

Toxicity to reproduction: other studies

Administrative data

Endpoint:

toxicity to reproduction: other studies

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

other: No guideline followed. No data on GLP.

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

1992

Report date:

1992

Materials and methods

Test guideline

Qualifier:

no guideline followed

GLP compliance:

not specified

Type of method:

in vivo

Test material

Test material information

Constituent 1

Reference substance name:

Theobromine

EC Number:

201-494-2

EC Name:

Theobromine

Cas Number:

83-67-0

Molecular formula:

C7H8N4O2

IUPAC Name:

theobromine

Test material form:

not specified

Details on test material:

- Name of test material (as cited in study report): Theobromine.- Other: Theobromine was purchased from Fisher Scientific Co. (Itasca, IL)

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male

Details on test animals or test system and environmental conditions:

TEST ANIMALS- Weight at study initiation: 230 to 250 g.

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

other: 5% gum acacia

Analytical verification of doses or concentrations:

no

Duration of treatment / exposure:

31 days.

Frequency of treatment:

Daily.

Duration of test:

32 days.

Doses / concentrations

Dose / conc.:

250 mg/kg bw/day

No. of animals per sex per dose:

4 males per dose

Control animals:

yes, concurrent vehicle

Details on study design:

The study was designed in order to compare the known toxic effects of theobromine alone in the reproductive male tract with toxic effects of the same amount of theobromine in a standardized cacao extract. For the present toxicity assessment only data concerning theobromine alone is presented in this study summary.

Statistics:

ANOVA with Sheffe's test for significance were used to determine the P values for the reproductive tract parameters. Fisher's two-tailed test was used to examine the significance of testis morphologic alterations.

Results and discussion

Effect levels

Dose descriptor:

dose level: 250 mg theobromine/ kg bdy weight

Effect level:

>= 250

Based on:

test mat.

Sex:

male

Basis for effect level:

other: Decreased body weight gain, decrease in epididymal weight, different histopathological changes.

Observed effects

Theobromine treated group exhibited a decrease body weight gain from day 16 of treatment. The rat epididymal weights were also decreased. No changes in testis weight or sperm concentration were observed.Animals treated with theobromine had wide-spread vacuolation of the seminiferous ephitelium and showed frequent multinucleate cells. Most of the vacuolations were present in stage I to VIII seminiferous tubules. Close examination of vacuoles suggested that they were associated with the Sertoli cell and were probably intracellular. Failed release of late spermatids and presence of abnormally shaped spermatids were observed in stages VIII to X tubules. The number of seminiferous tubules with failed release of late spermatids was significantly higher than in control (p < 0.01). Abnormally shaped elongate spermatids showed irregular shapes with hooks, triangular, or squared sides. These were not observed in any control slides.

Any other information on results incl. tables

Table 1. Reproductive tract parameters of rats treated with 250mg/kg theobromine for 31 days

	Control (n = 4)	TB 250 (n = 4)
Testis wt (g)	1.76 ± 0.20	1.64 ± 0.17
Testis wt/BW (*10^-3)	4.20 ± 0.57	4.50 ± 0.49
Epidid. wt (g)	0.56 ± 0.04	0.46 ± 0.02*
Epidid. wt /BW (*10^-3)	1.33 ± 0.13	1.26 ± 0.05
Cauda epi dwt (g)	0.27 ± 0.02	0.22 ± 0.01
Sperm count (*10^6)	236.3 ± 88.6	131.3 ± 28.9
Sperm count /cauda epi dwt (*10^6)	889.5 ± 375.7	605.1 ± 121.2

* P < 0.05.

Table 2. Testicular damage of rats treated with 250 mg/kg theobromine for 31 days.

	Control (n=4)	TB250 (n=4)
Number ST counted	235	253
Total number of vacuolations	0	113
Number of vacuo/ST	0	0.45
Number of ST with vacuolations	0	46
Number of stage I to VIII ST with vacuo	0	37
Total number of MNC	0	23
Number of ST with MNC	0	18
Number of ST with failed release	0	20

ST = seminiferous tubule.

MnC = multinuclate cells.

Vacuo = vacuolation.

Applicant's summary and conclusion

Conclusions:

The tested dose of theobromine (250 mg/kg) produced numerous alterations in the reproductive male tract of treated rats.

Executive summary:

The study was designed in order to compare the known toxic effects of theobromine alone in the reproductive male tract with toxic effects of the same amount of theobromine in a standardized cacao extract. Theobromine was administered by gavage to 4 rats in a concentration of 250 mg/kg for 31 days. The animals were sacrificed on day 32. One testis and epididymis were removed and weighed. The epididymis was saved for the determination of epididymal sperm reserves. The remaining testis was fixed by whole body glutaraldehyde perfusion and processed for morphologic examination. Theobromine caused numerous alterations in the reproductive male tract of the treated rats.