anti-inflammatory effects of oxymatrine through inhibition of nuclear factor–kappa b and mitogen-activated protein kinase activation in lipopolysaccharide-induced bv2 microglia cells

oxymatrine, a potent monosomic alkaloid extracted from chinese herb sophora japonica (sophora flavescens ait.). possesses anti-inflammatory activittyes.  this study was designed to investigate the effects of oxymatrine on nuclear factor–kappa b (nf-κb) and mitogen-activated protein kinase (mapk)-dependent inflammatory responses in lipopolysaccharide (lps)-activated microglia. in this paper, bv2 microglia were pretreated with different concentrations of oxymatrine (1, 10 and 20 μg/ml) for 30 min as followed by stimulation with lps (1 µg/ml) for different times (30 min, 1 h, 3 h, and 6 h). concentrations of nitric oxide (no), prostaglandin e2 (pge2), tumor necrosis factor-alpha (tnf-α), interleukin-1beta (il-1β) and interleukin-6 (il-6) in supernatant, mrna levels of inducible nitric oxide synthase (inos) and cyclooxygenase-2 (cox-2), cytosolic inhibitor of kappa b-alpha (i-κbα) and phospho-i-κbα and nuclear p65 protein levels, and the phosphorylations of mapk molecules such as extracellular-signal-regulated kinase (erk) 1/2, p38 mapk and c-jun n-terminal kinase (jnk) were determined. it was shown that oxymatrine inhibited the productions of no, pge2, tnf-α, il-1β and il-6, attenuated the mrna levels of inos and cox-2, suppressed the phosphorylation of i-κbα in cytosol, decreased the nuclear levels of p65, and also blocked erk, p38 and jnk pathway in lps-stimulated bv2 microglial cells in a dose-dependent manner. according to the results; it is suggested that oxymatrine may attenuate inflammatory responses of microglia and could be potentially useful in modulation of inflammatory status in the brain disorders.