Effect of anti-oxidants, free radical quenchers and cyclo-oxygenase inhibitor on benzo(a)pyrene-induced suppression of human lymphocyte mitogenesis in vitro.
BACKGROUND
Benzo(a)pyrene (BP) is a known carcinogen and immunosuppressor. Activation of BP to its reactive intermediates is cyclo-oxygenase (COX) dependent and occurs via a free radical dependent mechanism. The aim of this study was to know whether anti-oxidants, free radical quenchers and (COX) inhibitor, indomethacin, influence the suppression of human T cells induced by BP in vitro.


METHODS
Human lymphocytes, obtained from healthy human volunteers, were stimulated to proliferate using phytohaemagglutinin (PHA). The effect of vitamin E, SOD, catalase, mannitol, and COX-inhibitor, indomethacin, on BP-induced suppression of human T cell proliferation was evaluated.


RESULTS
Except for catalase, a hydrogen peroxide (H2O2) radical quencher, none of the agents tested could inhibit BP-induced suppression of human T cell proliferation in vitro.


CONCLUSIONS
BP-induced suppression of human T cell proliferation is probably, induced by increased production of H2O2. Prostaglandins and superoxide anion and hydroxyl radical do not seem to participate in BP-induced human T cell growth suppression.
Das
Undurti N
UN
EFA Sciences LLC, Norwood, MA 02062, USA.
D000975:Antioxidants / Q000494:pharmacology*; D001564:Benzo(a)pyrene / Q000494:pharmacology*; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology*; D016166:Free Radical Scavengers / Q000494:pharmacology*; D006801:Humans; D008214:Lymphocytes / Q000166:cytology / Q000187:drug effects*
D000975:Antioxidants; D016861:Cyclooxygenase Inhibitors; D016166:Free Radical Scavengers; D001564:Benzo(a)pyrene