Role of prostaglandin H synthase in activation of acrylonitrile to cyanide

ABSTRACT

The present study aimed at investigating the in-vitro oxidation of acrylonitrile [ACN] to cyanide [CN] by prostaglandin H synthase [PHS]. Detection of CN is considered a marker for free radical intermediates involved in ACN-induced toxicity. First, most favorable circumstances for ACN oxidation were characterized pH [4.5], temperature [37 degree C] and time of incubation [60 min.]. In addition, the concentrations of ACN, PHS and H2O2 in incubation mixtures were assessed for further reaction characterization. The reaction maximum velocity [Vmax] was calculated to be 582.75 pmol CN/mL/min and the Michaelis-Menten constant [Km] was 149.25 µmol ACN. Adding PHS inhibitors; resveratrol, quercetin, indomethacin or troloc-C to the reaction mixtures significantly reduced the rate of ACN oxidation. In conclusion, the present study demonstrates the ability of PHS to oxidize ACN to CN and provides a clue for the explanation of ACN target toxicity