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Updated: May 8, 2026
Magnetic Isolation of Microglial Cells from Neonate Mouse for Primary Cell Cultures
Published on: July 25, 2022
Phytoestrogens mediated anti-inflammatory effect through suppression of IRF-1 and pSTAT1 expressions in
Nattinee Jantaratnotai1, Pongsak Utaisincharoen, Pimtip Sanvarinda
1Department of Pharmacology, Mahidol University, Phayathai, Bangkok, Thailand.
Abstract:
Microglial activation has been implicated in various neurological disorders, including Alzheimer's disease, Parkinson's disease, multiple sclerosis, and HIV encephalopathy. Phytoestrogens have been shown to be neuroprotective in neurotoxicity models; however, their effect on microglia has not been well established. In the current study, we report that the soy phytoestrogens, genistein, daidzein, and coumestrol, decreased nitric oxide (NO) production induced by lipopolysaccharide (LPS) in the rat microglial cell line (HAPI). The levels of inducible NO synthase (iNOS) mRNA and protein expression were also reduced. Transcription factors known to govern iNOS expression including interferon regulatory factor-1 (IRF-1) and phosphorylated STAT1 were down regulated. These observations explain, at least in part, the inhibitory effect of phytoestrogens on NO production. The levels of monocyte chemoattractant protein-1 and interleukin-6 mRNA, proinflammatory chemokine and cytokine associated with various neurological disorders, were also reduced following LPS stimulation when HAPI cells were pretreated with phytoestrogens. Hence, genistein, daidzein, and coumestrol could serve as anti-inflammatory agents and may have beneficial effects in the treatment of neurodegenerative diseases.
Insights
Soy phytoestrogens like genistein significantly reduce inflammation in microglial cells. These compounds decrease nitric oxide and key inflammatory markers, suggesting potential benefits for neurodegenerative diseases.
Area of Science:
- Neuroscience
- Immunology
- Pharmacology
Background:
- Microglial activation is central to neurological disorders like Alzheimer's and Parkinson's.
- Phytoestrogens show neuroprotection, but their microglial effects are unclear.
Purpose of the Study:
- To investigate the impact of soy phytoestrogens on microglial inflammatory responses.
- To determine if genistein, daidzein, and coumestrol modulate nitric oxide production in microglia.
Main Methods:
- Utilized the rat microglial cell line (HAPI) stimulated with lipopolysaccharide (LPS).
- Assessed nitric oxide (NO) production, inducible NO synthase (iNOS) mRNA and protein levels.
- Measured transcription factors (IRF-1, STAT1) and inflammatory cytokines (MCP-1, IL-6) mRNA expression.
Main Results:
- Genistein, daidzein, and coumestrol significantly reduced LPS-induced NO production in HAPI cells.
- Phytoestrogen treatment decreased iNOS mRNA and protein expression.
- Downregulation of IRF-1 and phosphorylated STAT1 observed, explaining NO inhibition.
- Reduced levels of pro-inflammatory monocyte chemoattractant protein-1 and interleukin-6 mRNA.
Conclusions:
- Soy phytoestrogens effectively inhibit microglial inflammatory pathways.
- Genistein, daidzein, and coumestrol exhibit anti-inflammatory properties in microglia.
- These phytoestrogens may offer therapeutic potential for neurodegenerative diseases.