Manganese dioxide nanoparticles provoke inflammatory damage in BV2 microglial cells via increasing reactive oxygen species to activate the p38 MAPK pathway.

With the widespread use of manganese dioxide nanoparticles (nano MnO₂), health hazards have also emerged. The inflammatory damage of brain tissues could result from nano MnO₂, in which the underlying mechanism is still unclear. During this study, we aimed to investigate the role of ROS-mediated p38 MAPK pathway in nano MnO₂-induced inflammatory response in BV2 microglial cells. The inflammatory injury model was established by treating BV2 cells with 2.5, 5.0, and 10.0 μg/mL nano MnO₂ suspensions for 12 h. Then, the reactive oxygen species (ROS) scavenger (20 nM N-acetylcysteine, NAC) and the p38 MAPK pathway inhibitor (10 μM SB203580) were used to clarify the role of ROS and the p38 MAPK pathway in nano MnO₂-induced inflammatory lesions in BV2 cells. The results indicated that nano MnO₂ enhanced the expression of pro-inflammatory cytokines IL-1β and TNF-α, elevated intracellular ROS levels and activated the p38 MAPK pathway in BV2 cells. Controlling intracellular ROS levels with NAC inhibited p38 MAPK pathway activation and attenuated the inflammatory response induced by nano MnO₂. Furthermore, inhibition of the p38 MAPK pathway with SB203580 led to a decrease in the production of inflammatory factors (IL-1β and TNF-α) in BV2 cells. In summary, nano MnO₂ can induce inflammatory damage by increasing intracellular ROS levels and further activating the p38 MAPK pathway in BV2 microglial cells.