Benzoquinones inhibited the production of NO induced by LPS and gamma-IFN in C6 glia cells, The mechanistic studies showed that benzoquinones inhibited the expression of iNOS mRNA through inactivation of NF kappa B. Benzoquinones may be a useful candidate for the development of a drug to treat disease due to iNOS gene over-expression. (C) 1997 Academic Press.