Phy-Blica-O polyherbal formulation inhibits LPS-induced neuroinflammation by suppressing microglial NF-κB pathway

Neuroinflammation is a critical driver in the pathogenesis of neurodegenerative diseases, yet effective, safe interventions remain elusive. Current treatments often have limited efficacy or significant side effects, failing to adequately address the complex inflammatory cascades. The NF-κB signaling pathway is a central regulator of inflammatory responses in the brain, particularly in microglia, making it a key therapeutic target. This study investigates a traditional Thai polyherbal formulation, Phy-Blica-O (PBO), for its potential to modulate this pathway and offer neuroprotection.

Researchers evaluated the anti-neuroinflammatory effects of Phy-Blica-O in BV-2 microglial cells and male C57BL/6J mice challenged with lipopolysaccharide (LPS). In vitro, cells were pretreated with Phy-Blica-O 250 µg/mL before LPS exposure. In vivo, mice received oral Phy-Blica-O 100 mg/kg daily × 7 days prior to LPS. Primary endpoints included quantification of nitric oxide (NO), pro-inflammatory cytokines (TNF-α, IL-1β, IL-6), and inflammatory mediators (iNOS, COX-2) at mRNA and protein levels. NF-κB and MAPK signaling pathway activities were also assessed.

Phy-Blica-O (PBO) pretreatment significantly attenuated LPS-induced neuroinflammation. In vitro, PBO reduced NO overproduction from 15.69 ± 1.63 µM to 8.74 ± 0.25 µM at 250 µg/mL (p < 0.001). Pro-inflammatory cytokine mRNA expression was also significantly lowered: TNF-α by 25%, IL-1β by 31%, and IL-6 by 19% (p < 0.05). Inflammatory mediators iNOS and COX-2 protein expression decreased by 41% and 29%, respectively (p < 0.05). Mechanistic analysis confirmed PBO's action through the NF-κB pathway. > PBO reduced phosphorylated IκBα levels by 23% (p = 0.018) and phosphorylated p65 levels by 34% (p = 0.039) at 250 µg/mL in vitro, with no significant effect on MAPK signaling. These in vitro findings were corroborated by in vivo results, where oral PBO administration (100 mg/kg for 7 days) significantly lowered iNOS and COX-2 mRNA levels in mouse brain tissue.