Propofol inhibits human neutrophil functions

Neutrophils play important roles in the antibacterial host defense mechanism and in the pathogenesis of tissue injury. Propofol has been reported to impair the production of reactive oxygen species from neutrophils. We examined the effect of propofol (2,6-diisopropylphenol), at clinically relevant concentrations and at 10 and 100 times thus concentration, on several aspects of human neutrophil functions using an in vitro system. Propofol significantly inhibited chemotaxis, phagocytosis, and reactive oxygen species (ROS) (O₂/^-, H₂O₂, OH) production of neutrophils in a dose-dependent manner. At clinically relevant concentrations, propofol suppressed these neutrophil functions, but it did not decrease ROS generation by the cell-free (xanthine-xanthine oxidase) system. Increase in intracellular calcium concentrations in neutrophils stimulated by N-formyl- L-methionyl-leucyl-L-phenylalanine was dose-dependently attenuated by propofol. This decreasing effect on [Ca²⁺](i) in neutrophils may represent one of the mechanisms responsible for the inhibition of neutrophil functions by propofol. Implications: Neutrophils play a pivotal role in the antibacterial host defense system and tissue injury. We found that at clinically relevant concentrations, propofol impaired neutrophil functions. Further studies may determine whether this impairment, observed in vitro, leads to clinical immunological suppression.