Kaempferol exerts a neuroprotective effect to reduce neuropathic pain through TLR4/NF-ĸB signaling pathway

Area of Science:

• Neuroscience
• Immunology
• Pharmacology

Background:

• Neuropathic pain (NP) involves microglial activation, often polarized towards the M1 phenotype, contributing to chronic inflammation.
• Toll-like receptor 4 (TLR4) activation by lipopolysaccharide (LPS) drives neuroinflammation.
• Kaempferol, a dietary flavonoid, exhibits anti-inflammatory properties.

Purpose of the Study:

• To investigate the analgesic and anti-inflammatory effects of kaempferol in neuropathic pain.
• To elucidate the underlying mechanisms of kaempferol's action, focusing on microglial polarization and TLR4/NF-κB signaling.

Main Methods:

• Neuropathic pain model in vivo (chronic constriction injury) and LPS-induced microglial activation in vitro (BV2 cells).
• Assessment of pro-inflammatory cytokines, histological analysis (H&E, immunohistochemistry), Western blotting, immunofluorescence, quantitative real-time PCR, and flow cytometry.
• Evaluation of TLR4/NF-κB pathway activation and microglial M1/M2 polarization.

Main Results:

• Kaempferol significantly reduced neuropathic pain and pro-inflammatory cytokine production.
• Kaempferol attenuated the activation of the TLR4/NF-κB signaling pathway in LPS-stimulated BV2 cells.
• Kaempferol promoted the M2 microglial phenotype and inhibited M1 polarization.

Conclusions:

• Kaempferol demonstrates significant analgesic and anti-inflammatory effects in neuropathic pain.
• The mechanism involves the inhibition of the TLR4/NF-κB pathway and modulation of microglial polarization from M1 to M2.
• Kaempferol represents a potential therapeutic agent for neuropathic pain management.