Electroacupuncture Stimulation Alleviates Inflammatory Pain in Male Rats by Suppressing Oxidative Stress

Area of Science:

• Neuroscience
• Pain Management
• Biochemistry

Background:

• Chronic inflammatory pain is a significant health issue.
• Oxidative stress plays a role in pain sensitization.
• Electroacupuncture (EA) is a potential therapeutic modality for pain.

Purpose of the Study:

• To investigate the role of oxidative stress in the analgesic effects of EA.
• To determine the molecular mechanisms underlying EA's pain relief.
• To assess EA's impact on inflammation and oxidative stress markers in a rat model of chronic pain.

Main Methods:

• A chronic inflammatory pain model was induced in male rats using complete Freund's adjuvant (CFA).
• Animals were treated with EA stimulation at the 'zusanli' acupoint.
• Pain levels were assessed via paw withdrawal threshold (PWT).
• Spinal cord levels of inflammatory and oxidative stress markers were quantified using Western blotting and ELISA.
• In vitro studies used C6 cells to examine the effects of reactive oxygen species (ROS).

Main Results:

• EA treatment and antioxidants increased PWT in CFA-induced pain rats.
• ROS donors exacerbated pain and diminished EA's analgesic effect.
• EA inhibited inflammation (reduced TNF-α, IL-1β, IL-6, MDA) and oxidative stress (increased SOD, catalase activity).
• EA downregulated p-p38, p-ERK, p-p65, TRPV1, and TRPV4 expression.
• In vitro, ROS increased inflammatory markers and TRPV expression, which was blocked by an antioxidant.

Conclusions:

• Inhibition of oxidative stress and reactive oxygen species generation are crucial for EA's analgesic effect in chronic inflammatory pain.
• EA exerts its pain-relieving effects by modulating inflammatory pathways and ion channels involved in pain signaling.
• These findings support EA as a therapeutic strategy for managing chronic inflammatory pain through its antioxidant and anti-inflammatory actions.