Phytochemical Modulation of Astrocyte A1/A2 Polarization and Hepcidin-Associated Iron Dysregulation in LPS-Driven Neuroinflammation
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Background/Objectives
Neuroinflammation-driven iron dysregulation and neurotoxic astrocyte polarization are increasingly recognized as interconnected pathological mechanisms in neurodegenerative diseases. Systemic inflammation triggered by strenuous exercise or infection can engage the central nervous system and astrocytic inflammatory responses and perturb iron homeostasis; however, targeted nutritional strategies to counteract these processes remain limited. Inflamate® is a multi-component botanical supplement comprising boswellic acids, astilbin, xanthohumol, and cinnamaldehyde, each with documented anti-inflammatory properties. However, whether this combined formulation can modulate the inflammatory–iron metabolic axis and astrocyte phenotypic polarization remains unexplored. This study aimed to investigate the effects of Inflamate® on LPS-induced pro-inflammatory gene expression, iron metabolism-related gene regulation, and A1/A2 astrocyte phenotypic polarization in mouse astrocytes.
Methods
Mouse astrocytes (AWT) were pre-treated with Inflamate® (0.0375 μg/mL) or DMSO vehicle for 24 h, followed by lipopolysaccharide (LPS; 1 μg/mL) stimulation for an additional 24 h. The non-cytotoxic working concentration was determined by morphological assessment, CCK-8 cell viability, and LDH cytotoxicity assays. Expression of 14 target genes spanning pro-inflammatory mediators ( NOS2, IL6, C3, COX2, PLA2g15, SOCS3 ), iron metabolism regulators ( FTH1, Hepcidin, TFRC, SLC40A1, RGMa, RGMb ), and astrocyte polarization markers ( S100A10, GFAP ) was quantified by qRT-PCR.
Results
Under normal culture conditions, Inflamate® did not significantly alter the expression of any target gene except S100A10, confirming the absence of baseline cytotoxicity or transcriptional homeostatic perturbation. Upon LPS stimulation, Inflamate® selectively suppressed NOS2 (approximately 64% reduction, p < 0.0001), IL6 (approximately 37% reduction, p < 0.0001), and C3 (approximately 47% reduction, p < 0.0001), while COX2, PLA2g15, and SOCS3 remained unaffected. Concurrently, Inflamate® significantly reduced LPS-induced Hepcidin expression to approximately 17% of the control level (p < 0.05) and attenuated FTH1 upregulation (p < 0.01), without altering the expression of iron transporters (TFRC, SLC40A1) or BMP-SMAD pathway components (RGMa, RGMb). Furthermore, Inflamate® upregulated the neuroprotective A2 marker S100A10 under both basal (p < 0.05) and LPS-stimulated conditions (p < 0.01), while the general reactivity marker GFAP remained unchanged.
Conclusions
Inflamate® exerts a selective, multi-target modulatory effect at the transcriptional level in LPS-stimulated astrocytes, encompassing suppression of the iNOS–NO and IL-6 signaling axes, attenuation of inflammation-driven hepcidin–ferritin iron dysregulation via the IL-6–STAT3 pathway, and promotion of a phenotypic shift from neurotoxic A1 toward neuroprotective A2 astrocyte polarization. Given that the IL-6–JAK-STAT3–hepcidin axis is also activated during exercise-induced systemic inflammation, these findings suggest that Inflamate® may represent a targeted nutritional strategy for preserving CNS iron homeostasis and supporting neuroprotective astrocyte function in both neurodegenerative and exercise-related neuroinflammatory contexts. Further validation in in vivo neurodegenerative and exercise models, including protein-level analyses, is warranted to confirm these transcriptional findings.
