The increasing prevalence of neurodegenerative diseases has prompted investigation into innovative therapeutics over the last two decades. Non-steroidal anti-inflammatory drugs (NSAIDs) are among the therapeutic choices to control and suppress the symptoms of neurodegenerative diseases. However, NSAIDs-associated gastropathy has hampered their long term usage despite their clinical advancement. On the natural end of the treatment spectrum, our group has shown that cardamonin (2',4'-dihydroxy-6'-methoxychalcone) isolated from Alpinia rafflesiana exerts potential anti-inflammatory activity in activated macrophages. Therefore, we further explored the anti-inflammatory property of cardamonin as well as its underlying mechanism of action in IFN-γ/LPS-stimulated microglial cells. In this investigation, cardamonin shows promising anti-inflammatory activity in microglial cell line BV2 by inhibiting the secretion of pro-inflammatory mediators including nitric oxide (NO), prostaglandin E(2) (PGE(2)), tumour necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6). The inhibition of NO and PGE(2) by cardamonin are resulted from the reduced expression of inducible nitric oxide synthase (iNOS) and cycloxygenase-2 (COX-2), respectively. Meanwhile the suppressive effects of cardamonin on TNF-α, IL-1β and IL-6 were demonstrated at both protein and mRNA levels, thus indicating the interference of upstream signal transduction pathway. Our results also validate that cardamonin interrupts nuclear factor-kappa B (NF-κB) signalling pathway via attenuation of NF-κB DNA binding activity. Interestingly, cardamonin also showed a consistent suppressive effect on the cell surface expression of CD14. Taken together, our experimental data provide mechanistic insights for the anti-inflammatory actions of cardamonin in BV2 and thus suggest a possible therapeutic application of cardamonin for targeting neuroinflammatory disorders.
Matched MeSH terms: Nitric Oxide Synthase Type II/immunology
Nitric oxide (NO) may play a crucial role in the pathogenesis of periodontal disease and, hence, the aim of the present study was to test the hypothesis that Aggregatibacter actinomycetemcomitans surface-associated material (SAM) stimulates inducible nitric oxide synthase (iNOS) activity and NO production by the murine macrophage cell line RAW264.7. Cells were stimulated with untreated or heat-treated A. actinomycetemcomitans SAM and with or without pre-treatment with L-N(6)-(1-Iminoethyl)-lysine (L-NIL) (an iNOS inhibitor), polymyxin B, interferon-gamma (IFN-γ) and Interleukin-4 (IL-4), IL-10, genistein [a protein tyrosine kinase (PTK) inhibitor], bisindolylmaleimide [a protein kinase C (PKC) inhibitor], bromophenacyl bromide (BPB) [a phospholipase A(2) (PLA2) inhibitor] or wortmannin [phosphatidylinositol 3-kinase (PI-3K) inhibitor]. The iNOS activity and nitrite production in the cell cultures were determined. Untreated but not heat-treated A. actinomycetemcomitans SAM-stimulated both iNOS activity and nitrite production in RAW264.7 cells. L-NIL, IL-4, IL-10, genistein, bisindolylmaleimide, or BPB, suppressed but IFN-γ enhanced both iNOS activity and nitrite production by A. actinomycetemcomitans SAM-stimulated cells. Wortmannin and polymyxin B failed to alter both iNOS activity or nitrite production by A. actinomycetemcomitans SAM treated cells. Therefore, the present study suggests that a heat-sensitive protein constituent(s) of A. actinomycetemcomitans SAM stimulates both iNOS activity and nitrite production by RAW264.7 cells in a cytokine, PTK, PKC, and PLA(2) but not PI-3K-dependent fashion.
Matched MeSH terms: Nitric Oxide Synthase Type II/immunology