POSSIBLE TOXICOLOGICAL EFFECTS ASSOCIATED WITH CHRONIC DERMAL EXPOSURE TO PARA-PHENYLENEDIAMINE (PPD) ON PANCREAS OF ADULT MALE ALBINO RATS

Abstract

Paraphenylenediamine (PPD) is a chemical compound that is commonly used as dark cosmotics and in hair coloring. The aim of this work is to evaluate toxic effect of chronic dermal exposure to PPD on pancreas. Methods: Forty adult male albino rats were used in this study divided into; control group (10 rats) painted on their dorsal sides with 2 ml distilled water and PPD- exposed group (30 rats) was divided into 3 groups; groups I, II and III which were exposed to PPD dermally by painting their dorsal sides with 1, 2, and 3 mg/kg of PPD respectively (dissolved in 2 ml distilled water) daily for 12 weeks. At the end of the study, all rats were tested for intraperitoneal glucose tolerance test (IPGTT), Hemoglobin A1c (HbA1C) and plasma insulin levels. Histopathological examination and immunohistochemical studies for PCNA and insulin were also performed. Results: The results revealed significant glucose intolerance with decreased level of plasma insulin level in PPD-exposed rats when compared with control group. On histopathological examination, PPD groups showed vacuolations in cells of islets of Langerhans, irregular distorted acini, and congested blood vessels. Immunohistochemical staining revealed weak positive immunoreaction for insulin with significant decrease in area percentage of positive insulin immunoreaction and strong positive immunoreaction for PCNA in groups II and III. Conclusion: It was concluded that chronic dermal exposure to PPD resulted in dose-dependent toxic effects on pancreas, with recommendations to avoid chronic dermal exposure to hair dyes containing PPD and adherence to wear protective gloves when chronic handling of these dyes is necessary.