Neuroinflammation is an integral part of neurodegenerative diseases. Lipo-polysacharide (LPS) induces reactive astrogliosis, the cellular manifestation of neuroinflammation, in various models of neurological diseases, but its mechanism of action is still not properly known. The effect of guggulipid and nimesulide on LPS-induced neuroinflammatory changes is also not properly understood. This work demonstrated the mechanism of actions of guggulipid and nimesulide on inflammatory genes expressions in LPS-stimulated rat astrocytoma cells, C6. We observed that LPS (10 μg/ml) treatment of rat astrocytoma cells, C6, for 24 h significantly increased intracellular Ca(2+) ion and expression of inducible nitric oxide synthase (iNOS), nuclear factor kappa-B (NF-kB), C/EBP homologous protein 10 (CHOP), c-fos, and c-jun proteins. At transcriptional stage, LPS upregulated mRNA levels of cyclooxygenase-2 and IL-6 with downregulation in IL-1α, IL-1β, and microsomal prostaglandin E synthase-1 (mPGES-1) through activating NF-kB translocation. Treatment with guggulipid reversed these LPS-induced changes in rat astrocytoma cells. Treatment with nimesulide also attenuated LPS-induced Ca(2+) ion, iNOS, NF-kB, and c-fos expressions, but does not significantly influence CHOP, c-jun protein expressions, and mRNA levels of IL-6, IL-1α, IL-1β, and mPGES-1 genes. In conclusion, our findings elucidated the molecular mechanism of neuroinflammation in response to LPS and its modulation by guggulipid and nimesulide in rat astrocytoma cells (C6), which suggest the use of these drugs in the treatment of neuroinflammation-associated disorders.