Oxymatrine Alleviates Central Post-Stroke Pain in Rats by Reducing the Inflammatory Response

Area of Science:

• Neuroscience
• Pharmacology
• Immunology

Background:

• Central post-stroke pain (CPSP) is a chronic neuropathic pain condition resulting from cerebrovascular damage.
• CPSP is characterized by poor response to conventional pain medications.
• Oxymatrine (OMT), a natural compound from Sophora flavescens Ait., possesses anti-inflammatory and analgesic properties.

Purpose of the Study:

• To investigate the therapeutic potential of Oxymatrine (OMT) in a rat model of central post-stroke pain (CPSP).
• To evaluate the effects of OMT on pain thresholds, inflammatory markers, and glial cell activation in CPSP.

Main Methods:

• A rat model of CPSP was established via focal hemorrhage in the ventral posterolateral nucleus.
• Rats received daily intraperitoneal injections of varying doses of OMT or saline.
• Pain sensitivity (paw withdrawal mechanical thresholds), inflammatory cytokines (IL-1β, IL-6, TNF-α), and glial cell activation were assessed.

Main Results:

• CPSP rats exhibited elevated inflammatory markers and activated microglia and astrocytes around the thalamic lesion.
• OMT treatment significantly reduced mechanical allodynia in CPSP rats.
• OMT administration dose-dependently decreased pro-inflammatory cytokine levels and inhibited microglial and astrocytic activation.

Conclusions:

• Oxymatrine (OMT) demonstrates significant therapeutic effects in mitigating central post-stroke pain (CPSP) in a preclinical rat model.
• OMT exerts its analgesic effects by attenuating neuroinflammation at the thalamic lesion site.
• OMT shows promise as a potential therapeutic agent for managing central post-stroke pain.