No abstract

Inflammation is major symptom of the innate immune response by infection of microbes. Macrophages, one of immune response related cells, play a role in inflammatory response. Recent studies reported that various natural products can regulate the activation of immune cells such as macrophage. Sargassum horneri (Turner) C. Agardh is one of brown algae. Recently, various seaweeds including brown algae have antioxidant and anti-inflammatory effects. However, anti-inflammatory effects of Sargassum horneri (Turner) C. Agardh are still unknown. In this study, we investigated anti-inflammatory effects of ethanolic extract of Sargassum horneri (Turner) C. Agardh (ESH) on RAW 264.7 murine macrophage cell line. The ESH was extracted from dried Sargassum horneri (Turner) C. Agardh with 70% ethanol and then lyophilized at -40 °C. ESH was not cytotoxic to RAW 264.7, and nitric oxide (NO) production induced by LPS-stimulated macrophage activation was significantly decreased by the addition of 200 μg/mL of ESH. Moreover, ESH treatment reduced mRNA level of cytokines, including IL-1β, and pro-inflammatory genes such as iNOS and COX-2 in LPS-stimulated macrophage activation in a dose-dependent manner. ESH was found to elicit anti-inflammatory effects by inhibiting ERK, p-p38 and NF-κB phosphorylation. In addition, ESH inhibited the release of IL-1β in LPS-stimulated macrophages. These results suggest that ESH elicits anti-inflammatory effects on LPS-stimulated macrophage activation via the inhibition of ERK, p-p38, NF-κB, and pro-inflammatory gene expression.

Neuroinflammation resulting from microglial activation is involved in the pathogenesis of neurodegenerative diseases, including Parkinson's diseases. Microglial activation plays an important role in neuroinflammation and contributes to several neurological disorders. Hence, inhibition of both microglial activation and the generation of pro-inflammatory cytokines may lead to an effective treatment for neurodegenerative diseases. In the present study, the anti-neuroinflammatory effects of galangin were investigated in lipopolysaccharide (LPS)-stimulated BV-2 microglial cells. Galangin significantly decreased the generation of nitric oxide, interleukin-1β, and inducible nitric oxide synthase in LPS-stimulated BV-2 microglial cells. In addition, galangin inhibited the phosphorylation of p38 mitogen-activated protein kinase (MAPK) and c-Jun N-terminal kinase 1/2. Furthermore, it was observed that activation of both IκB-α and nuclear factor kappa B (NF-κB) was significantly increased following LPS stimulation, and this effect was suppressed by galangin treatment. In conclusion, galangin displayed an anti-neuroinflammatory activity in LPS-stimulated BV-2 microglial cells. Galangin inhibited LPS-induced neuroinflammation via the MAPK and NF-κB signaling pathways and might act as a natural therapeutic agent for the treatment of various neuroinflammatory conditions.

Our results indicate that myricetin is a potent inducer of HATC cell death and may thus prove useful in the development of therapeutic agents for HATC.

We previously isolated pseudane-VII from the secondary metabolites of Pseudoalteromonas sp. M2 in marine water, and demonstrated its anti-inflammatory efficacy on macrophages. However, the molecular mechanism by which pseudane-VII suppresses neuroinflammation has not yet been elucidated in brain microglia. Microglia is activated by immunological stimulation or brain injury. Activated microglia secrete proinflammatory mediators which damage neurons. Neuroinflammation appears to be associated with certain neurological diseases, including Parkinson’s disease and Alzheimer’s disease. Natural compounds that suppress microglial inflammatory responses could potentially be used to prevent neurodegenerative diseases or slow their progression. In the present study, we found that pseudane-VII suppresses neuroinflammation in lipopolysaccaride (LPS)-stimulated BV-2 microglial cells and brain. Pseudane-VII was shown to inhibit the LPS-stimulated NO, ROS production and the expression of iNOS and COX-2. To identify the signaling pathway targeted by pseudane-VII, we used western blot analysis to assess the LPS-induced phosphorylation state of p38, ERK1/2, JNK1/2, and nuclear factor-kappaB (NF-κB). We found that pseudane-VII attenuated LPS-induced phosphorylation of MAPK and NF-κB. Moreover, administration of pseudane-VII in mice significantly reduced LPS-induced iNOS expression and microglia activation in brain. Taken together, our findings suggest that pseudane-VII may represent a potential novel target for treatment for neurodegenerative diseases.