Antioxidant activity of humic substances via bioluminescent monitoring in vitro

摘要

This work considers antioxidant properties of natural detoxifying agents-humic substances (HS) in solutions of model inorganic and organic compounds of oxidative nature-complex salt K-3[Fe(CN)(6)] and 1,4-benzoquinone. Bioluminescent system of coupled enzymatic reactions catalyzed by NAD(P) H:FMN-oxidoreductase and bacterial luciferase was used as a bioassay in vitro to monitor toxicity of the oxidizer solutions. Toxicities of general and oxidative types were evaluated using bioluminescent kinetic parameters-bioluminescence intensity and induction period, respectively. Antioxidant activity of HS was attributed to their ability to decrease both general and oxidative toxicities; the HS antioxidant efficiency was characterized with detoxification coefficients D-GT and D-OxT, respectively. Dependencies of D-GT and D-OxT on HS concentration and time of preliminary incubation of the oxidizers with HS were demonstrated. The optimal conditions for detoxification of the oxidizers were >20-min incubation time and 0.5x10(-4) to 2x10(-4) M of HS concentration. The present study promotes application of the enzymatic luminescent bioassay to monitor toxicity of pollutants of oxidative nature in environmental and waste waters in remediation procedures.