α-Tocopherol protected against cobalt nanoparticles and cocl₂ induced cytotoxicity and inflammation in Balb/3T3 cells

Currently, tissue damage induced by cobalt nanoparticles (CoNPs) and cobalt ions (Co²⁺) are the most serious adverse effect in the patients with metal-on-metal hip prostheses. Therefore, an urgent need exists for the identification of the mechanisms and the development of therapeutic strategies to limit it.

We aimed to explore the mechanisms of cytotoxicity of CoNPs and Co²⁺ and developed strategies to reduce this cytotoxicity with α-tocopherol treatment.

To evaluate the protective effect of α-tocopherol, Balb/3T3 cells were pretreated with 10 μM α-tocopherol for 24 h. The cells were then exposed to different concentrations of CoNPs and Co²⁺ for 12 h, 24 h and 48 h. The cell viabilities, reactive oxygen species (ROS), inflammatory cytokines and MAP kinase (MAPK) levels were measured.

CoNPs and Co²⁺ can induce the increase of ROS and inflammatory cytokines in Balb/3T3 cells, such as tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6). However, α-tocopherol pretreatment can significantly prevent cytotoxicity induced by CoNPs and Co²⁺, decrease ROS production and decrease levels of inflammatory cytokines in Balb/3T3 cells. Additionally, MAPK pathway may be involved in the protection of α-tocopherol against cytotoxicity induced by CoNPs and Co²⁺ in vitro.

Our results provide new insights into the potential therapeutic use of α-tocopherol in the prevention and treatment of various oxidative- or inflammatory stress-related inflammation and injuries.