Effects of tetrandrine on COX-2/PGE_2,iNOS/NO expression in LPS-stimulated RAW264.7 cells

The effects of tetrandrine(Tet) on the expression of cyclooxygenase-2(COX-2),prostaglandin E2(PGE2),inducible isoforms of nitric oxide synthetase(iNOS) and nitric oxide(NO) in LPS-stimulated RAW264.7 cells were investigated.RAW 264.7 cells were pretreated with LPS 1 μg/mL to set up the cell inflammatory model;various concentrations(1×10-8,1×10-7,1×10-6 mol/L) of Tet were administered to explore its effect on the expression of COX-2/PGE2,iNOS/NO in these LPS-stimulated cells.Western blotting was applied to detect the expression of intracellular COX-2 and iNOS;special NO kit was used to detect the level of NO,and enzyme immunoassay(EIA) kit to that of PGE2.The results showed that Tet significantly decreased the expression of PGE2 and NO as well as COX-2 and iNOS synthetase in LPS-stimulated RAW264.7 cells in a dose-dependent manner.So it suggests that Tet can inhibit the inflammation response in LPS-stimulated RAW264.7 cell,which might be mediated by down-regulating the expression of PGE2 and NO through the inhibition of COX-2 and iNOS synthetase.