Methanol Extract of <i>Myelophycus caespitosus</i> Inhibits the Inflammatory Response in Lipopolysaccharidestimulated BV2 Microglial Cells by Downregulating NF-kB via Inhibition of the Akt Signaling Pathway

Abstract

Purpose: To determine whether the methanol extract of Myelophycus caespitosus (MEMC) downregulates the expression of pro-inflammatory mediators in lipopolysaccharide (LPS)-stimulated BV2 microglial cells. Methods: Reverse transcription-polymerase chain reaction (RT-PCR) together with Western blot analysis was used to evaluate the expression of pro-inflammatory mediators such as nitric oxide (NO) and prostaglandin E2 (PGE2) as well as their regulatory genes such as inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2), in LPS-stimulated BV2 microglial cells. The level of NO production was analyzed using Griess reaction. The release of PGE2 was determined using sandwich enzyme-linked immunosorbent assay. The DNA-binding activity of nuclear factor-κB (NF-κB) was measured by electrophoretic mobility shift assay. Results: MEMC inhibited LPS-induced pro-inflammatory mediators, NO and PGE2, as well as their respective genes, iNOS and COX-2, at both protein and mRNA levels, without any significant cytotoxicity. Treatment with MEMC also substantially reduced the LPS-induced DNA-binding activity of NF-κB and nuclear translocation of NF-κB subunits p65 and p50 via the inhibition of IκBα phosphorylation and degradation. MEMC promoted dephosphorylation of Akt that subsequently suppressed the DNA-binding activity of NF-κB in LPS-stimulated BV2 microglial cells. Conclusion: Collectively, these data suggest that MEMC attenuates expression of pro-inflammatory mediators such as NO and PGE2 by suppression of their regulatory genes through the inhibition of Aktmediated NF-κB activity.

Review: Prospects for the Use of Extracts and Polysaccharides from Marine Algae to Prevent and Treat the Diseases Caused by Helicobacter pylori

“…Fucoidan from the alga Polyopes affinis suppressed the formation of PGE2 and NO through inhibition of the expression of corresponding genes in microglial BV2 cells, stimulated by LPS , and also inhibited IFNα in glial cells .…”

Methanol extract of Myelophycus caespitosus ameliorates oxidative stress-induced cytotoxicity in C2C12 murine myoblasts via activation of heme oxygenase-1

“…Although we have reported that a methanol extract of M. caespitosus (MEMC) has potent anti-inflammatory effects in BV2 microglial cells (Jayasooriya et al, 2012), scientific evidence for the pharmacological efficacy of M. caespitosus, including its antioxidant properties, is very limited. Therefore, the objective of the present study was to investigate the antioxidant capacity of MEMC against oxidative stress-mediated cytotoxicity in muscle cells.…”