Testicular toxicity of para-phenylenediamine after subchronic topical application in rat

Para-phenylenediamine (PPD) is a most widely used chemical in almost all hair dye formulations. The present experiment was conducted in order to assess the reproductive toxicity of PPD in male rats. After sub-chronic topical application of different doses (0, 1, 2 and 3 mg/kg/day) of PPD, the male albino rats exhibited significant decrease in the total sperm count (p<0.05, 0.01) with consistent decrease in the testicular weight (p<0.05), increase in the germ cell apoptosis indicated by cellular morphology as well as loss of germinal layer, sloughing of testicular cellular layers. Elevation of lipid peroxidation product in the testicular tissue indicated the potential oxidative stress that may be crucial in the induction of the apoptosis and further tissue injury in the PPD-treated rats. The study was designed to examine the testicular effect of 1% to 3% PPD which mimic the actual dosage available in most of the hair dying formulation. The possibilities of impaired testicular function after sub-chronic topical exposure to PPD on male rats have demonstrated.