Characterization of a method for the detection of drugs with free radical scavenging activity using porcine leukocytes.
The effects of a range of free-radical scavenging drugs on luminol-enhanced chemiluminescence (CL) generated by porcine leukocytes, following activation by two nonreceptor-mediated stimulants, phorbol myristate acetate (PMA; a protein kinase activator) and ionomycin (a cation ionophore), and by xanthine plus xanthine oxidase (X-XO), have been examined. Superoxide dismutase (0.1 units/mL) and catalase (50 units/mL) inhibited X-XO, but they were ineffective in leukocyte suspensions except at concentrations 500 times and 20 times higher. Sodium azide (10(-5) to 10(-3) M) caused a marked inhibition in CL production in activated leukocytes, but not of X-XO CL. The antioxidants, glutathione (10(-3) M) and L-ascorbic acid (10(-3) M) were ineffective in activated leukocytes, but caused total inhibition of X-XO-induced CL. Mannitol (100 mM) had no effect on chemiluminescence in either system. Captopril (10(-3) M) produced an inhibition of CL in both systems and this inhibition was significantly modified by pH. Thus, the present study has established a standard screening procedure for the assessment of free-radical scavenging activity using activated porcine leukocytes and xanthine-xanthine oxidase.
Department of Physiology and Pharmacology, Strathclyde Institute for Drug Research, University of Strathclyde, Glasgow, Scotland, United Kingdom.
A T
AT
Demiryürek
C L
CL
Wainwright
R M
RM
Wadsworth
K A
KA
Kane
D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D001386:Azides / Q000494:pharmacology; D002216:Captopril / Q000494:pharmacology; D002374:Catalase / Q000494:pharmacology; D004353:Drug Evaluation, Preclinical / Q000379:methods*; D016166:Free Radical Scavengers / Q000032:analysis* / Q000494:pharmacology*; D015759:Ionomycin / Q000494:pharmacology; D007962:Leukocytes / Q000187:drug effects* / Q000378:metabolism; D008163:Luminescent Measurements; D008353:Mannitol / Q000494:pharmacology; D019810:Sodium Azide; D013482:Superoxide Dismutase / Q000494:pharmacology; D013552:Swine; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D019820:Xanthine; D014969:Xanthine Oxidase / Q000494:pharmacology; D014970:Xanthines / Q000494:pharmacology
D000975:Antioxidants; D001386:Azides; D016166:Free Radical Scavengers; D014970:Xanthines; D019820:Xanthine; D008353:Mannitol; D015759:Ionomycin; D019810:Sodium Azide; D002216:Captopril; D002374:Catalase; D013482:Superoxide Dismutase; D014969:Xanthine Oxidase; D013755:Tetradecanoylphorbol Acetate