Diphenylamine (DPA) is an aniline derivative, used widely as an industrial antioxidant, dye mordant, and agricultural fungicide. DPA was reported as hazardous to mammals both acutely and chronically, however little is known about the toxicity of DPA and its derivatives during pregnancy. This study aimed to evaluate and explain the possible mechanism of toxicity induced by DPA on blood and spleen, as a fundamental hematopoietic target organ, in pregnant rats and their fetuses. Pregnant rats were orally administrated distilled water, corn oil, and/or DPA (400 mg/kg b.wt) from the 5th to 19th day of gestation. DPA-induced spleen toxicity was mirrored by significant upregulation of programmed death-1 (PD-1) protein expression and an increase in the percentage of apoptotic cells and a decrease in their proliferating capacity. These results have been confirmed through marked G0/G1 cell-cycle arrest that was observed by flow cytometric analysis of spleen cells. Moreover, the contents of reactive oxygen species and iron in the spleen tissue were significantly higher than that of the control group. DPA resulted in severe anemia, decreased hemoglobin and hematocrit, thrombocytopenia and leukopenia in addition to significant changes in differential leukocytic count of both mothers and fetuses. Evidently, DPA triggered serious pathological changes in the spleen tissue of both mothers and fetuses and the histochemical examination revealed a significant increase in iron expression. In conclusion, these results implicate the hemato- and splenotoxicity of DPA and the possible role of oxidative stress and apoptosis in DPA-induced toxicity in the spleen of pregnant rats and their fetuses. This in-turn suggests the urgent need to reduce exposure to DPA as possible as it can.
Keywords: apoptosis; cell cycle; diphenylamine; hematotoxicity; oxidative stress; pregnant rats; spleen toxicity.
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