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additional toxicological information
Type of information:
experimental study
Adequacy of study:
supporting study
Study period:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
test procedure in accordance with generally accepted scientific standards and described in sufficient detail
Justification for type of information:
Information from published report, no GLP but peer reviewed.

Data source

Reference Type:
Report date:

Materials and methods

Type of study / information:
Experimental dapsone administration induces infertility in male Wistar rats: Mechanisms and clinical implications
Test guideline
other: Both in vivo and in vitro methods used
Version / remarks:
See Principles of method if other than guideline
Principles of method if other than guideline:
This study investigated the effect of the administration of dapsone on the reproductive activities of male rats using in vivo and in vitro techniques. In the in vivo study, dapsone was administered orally to male Wistar rats for 5 days or 6 weeks after which their body weight, relative reproductive organ weights, sperm parameters and reproductive hormones were determined while testicular and epididymal histology were also assessed.
Data were compared using analysis of variance and Students-Newman-Keuls multiple comparison test.
For the in vitro study, Sertoli cells were cultured and treated with varying doses of dapsone at different durations, thereafter Sertoli cell viability and nuclei integrity were determined. Also, the genetic
expressions of Glial cell line-derived neurotrophic factor (GDNF) and transferrin were assessed.

In vivo research:
Thirty male rats were divided into 5 groups containing 6 rats per group. They were matched weight for weight and administered dapsone as follows. Rats in group 1 received distilled water (vehicle) for 5 days and served as the control. Group 2 contained rats that were administered 1.4 mg/kg body weight of dapsone 5 days to mimic its use as an antimalarial drug.
Group 3 rats received distilled water (vehicle) for 6 weeks. They served as the control animals for the long-term study. Group 4 rats were administered 1.4 mg/kg body weight of dapsone daily for 6
weeks. This was to mimic the use of dapsone in the long term treatment of leprosy, Dermatitis herpetiformis and also to expose the gametes to the chronic effects of the drug [28–30]. Group 5
rats received this same dose of dapsone daily for 6 weeks and were allowed a recovery period of 6 weeks (Table 1). The dose administered in this study was deduced from that used in humans. Dapsone was administered to rats orally using the oral cannula. The rats were closely observed during the period of dapsone administration for signs of toxicity before necropsy.

In vitro research:
Sertoli cells were isolated from the testes of Sprague–Dawley rats (16–18 days old) as earlier described. They were cultured in DMEM/F-12 medium (Sigma-Aldrich). It was supplemented with
transferrin (5 mg/L), vitamins A and E (200 ng/ml), insulin (5 mg/L), gentamicin sulfate (25 mg/L) (Sigma-Aldrich) and sodium bicarbonate (1.2 g/L) in a humidified atmosphere of 5% CO2/95% air at
34 ◦C at a density of 1 × 106 cells/25 mm2 area. 48 h later, the cells were treated with 20 mM Tris buffer (pH 7.6) for 3 min to remove the contaminating germ cells. The Sertoli cells were then plated in
48-well tissue culture plates and fresh DMEM/F-12 medium were added and further supplemented with follicle stimulating hormone (0.05 Units/ml) and testosterone (10−6 M). The cultured Sertoli cells
were then subjected to the following treatments and test procedures;
-Sertoli cell viability test using the M.T.T. Assay technique
-Determination of dsDNA integrity using fluorescence microscopy
-Quantitative reverse transcriptase - polymerase chain reaction (RT-PCR)
GLP compliance:
not specified

Test material

Constituent 1
Chemical structure
Reference substance name:
EC Number:
EC Name:
Cas Number:
Molecular formula:
Details on test material:
Pharmaceutical grade Dapsone

Results and discussion

Any other information on results incl. tables

3.2. Serum hormone concentration

There was no significant change in the serum concentrations of luteinizing hormone and follicle stimulating hormone in rats treated with dapsone for 5 days when compared with the control. This was also observed in rats treated for 6 weeks when compared with their control (Figs. 1 and 2). Administration of dapsone to rats for 5 days and 6 weeks respectively significantly decreased their serum testosterone level when compared with their control. However, there was significant increase in serum testosterone concentration of rats in the recovery group when compared with the rats treated for 6 weeks.

3.3 Sperm Perameters

Administration of dapsone to rats for 5 days did not case any significant change in their progressive sperm motility, sperm viability, sperm count or morphology when compared with control. A significant decrease was observed with progressive motility, sperm viability and count of rats treated for 6 weeks when compared with control. However, there was a significant increase in these parameters in the rats in the recovery group wen compared with those treated for 6 weeks. There was no change in normal morphology in these treated rats when compared with control.

3.4 Daily Sperm Production

There was no significant change in the daily sperm porduction of rats administered dapsone for 5 days when compared with their control, whereas a significant decrease was obserbed in the daily sperm production of rats treated with dpasone for 6 weeks when compared with their control. However, rats in the recovery group showed a significant increase in their daily sperm production when compared with the treated group.

3.5 Histomophometric analysis

Administreation of dapsone to rats caused duration-dependent degenerative changes in their epididymis and testis. Rats treated with dapsone for 5 days showed none to mild degenerative changes when compared with the control while the eppididymis and testis of rats treated for 6 weeks showed severe degenerative changes. There was visible vacuolization within the epididymal structure as evidenced by reductions in sperm content. The testicular histology showed distortion and disorganization of the seminiferous tubular architecture, degeneration of the plasmalemma with posible arrest of spermatogenesis. These degenerative chanes were however observed to be reversed in the epididymal and testicular histology of rats in the recovery group.

3.6 Mating Studies

Number of live pups from treated males was decreased when compared with the number of pups from untreated males, although this decrease was not statistically significant.

3.7 Sertoli cell viability

The results obtained from the MTT assay in the determination of sertoli cell viability showed a dose and duration dependent inhibition of sertoli cell growth. The least growth inhibition was observed at a dose of 0.3 uM for 24h while the highest growth inhibition was observed at a dose of 10 uM for 120h.

3.8 Sertoli cell nuclei integrity

Results showed a dose and duration-dependant fragmentation of ds-DNA with 2.5 uM showing the least effect at 24h while the greatest occurence of fragmentation was observed at 10 uM for 120h.

3.9 Sertoli cell gene expression

The expression of the housekeeping gene in the sertoli cell showed normal expression. Glial cell line derived neurotrophic factor (GDNF) and transferrin genes showed normal expression in sertoli cells treated with 5 uM, 2.5 uM and 1.25 uM of dapsone when compared with the gene expression in control sertoli cells.

Applicant's summary and conclusion

Dapsone administration has been shown to induce male reproductive toxicity at the testicular and epididymal levels. However, these deleterious changes appeared to be reversed upon
cessation of dapsone administration. This might imply that continuous use of dapsone should be done with great caution as the greatest deleterious effects observed in this study were in the long
term study.