Oxidative damage in the liver and kidney induced by dermal exposure to diisononyl phthalate in Balb/c mice

Abstract

As a general alternative, diisononyl phthalate (DINP) has gradually replaced di(2-ethylhexyl) phthalate (DEHP) as the main plasticizer used in polyvinyl chloride. Like DEHP, DINP can also be released into the environment, resulting in humans being exposed through skin contact. This study aims to explore whether oxidative damage to hepatic and renal tissues can be induced by dermal exposure to DINP in mice. Forty-two male Balb/c mice were divided into six groups. The five DINP dermal exposure groups were exposed to different doses of DINP (0.02, 0.2, 2, 20, and 200 mg/kg) for 28 consecutive days. The pathological alterations to the skin, liver, and kidney in the mice were examined. Levels of reactive oxygen species (ROS), reduced glutathione (GSH), malondialdehyde (MDA), and DNA-protein cross-links (DPC) in the liver and kidney were also determined to investigate oxidative damage. The experimental results showed that the levels of ROS, MDA, and DPC coefficients increased gradually in a dose-dependent manner, whereas the level of GSH decreased accordingly. When the exposure dose was ≥20 mg/kg, ROS, GSH, MDA content, and the DPC coefficient were significantly different compared to the control group (p < 0.05). These results suggest that a high dose of DINP can induce oxidative stress and histopathological alterations in the liver and kidney via dermal exposure.