1,2,4-trihydroxybenzene induces stress granule formation and causes DNA damage in human keratinocytes

Household chemical products are typically evaluated for toxicity through ingestion and inhalation, with limited information on skin absorption. Furthermore, current research focuses on the long-term toxic effects of harmful substances contained in these household chemical products, however not much is known about their acute toxic effects. In this study, the effects of 1,2,4-trihydroxybenzene (THB) in human keratinocytes by examining its effects on stress granule (SG) formation, a marker of acute stress response, and DNA double strand breaks caused by repeated exposure. THB effectively induced SG formation via endoplasmic reticulum stress-mediated eIF2α phosphorylation in keratinocytes. Furthermore, repeated exposure to THB causes apoptotic cell death due to DNA double strand breaks. Collectively, THB exposure leads to skin toxicity, suggesting precautions for the use of THB-containing household chemical products.