Common trace elements alleviate pain in an experimental mouse model

Area of Science:

• Biochemistry
• Pharmacology
• Neuroscience

Background:

• Trace elements are vital for life, present in minute quantities.
• Analgesic adjuvants can potentiate pain relief or act as standalone analgesics.
• Previous research on trace elements' effects on nociception and their adjuvant potential yielded conflicting results.

Purpose of the Study:

• To test the hypothesis that zinc (Zn²⁺), magnesium (Mg²⁺), and copper (Cu²⁺) possess direct antinociceptive effects.
• To evaluate the efficacy of these trace elements as potential analgesic adjuvants.

Main Methods:

• Swiss mice were administered varying intraperitoneal doses of Zn²⁺, Mg²⁺, and Cu²⁺ salts or saline (control).
• Antinociceptive effects were assessed using hot plate (HP) and tail flick (TF) tests for central pain.
• Visceral pain was evaluated via the writhing test (WT), and spontaneous behavior was monitored in an activity cage (AC).

Main Results:

• Zinc (Zn²⁺) induced significant pain inhibition in HP/TF (up to 17%) and WT (up to 25%) tests.
• Magnesium (Mg²⁺) salts demonstrated potent pain inhibition across all tests, notably up to 85% in the WT.
• Copper (Cu²⁺) salts exhibited antinociceptive effects in HP/TF (up to 28.6%) and WT (57.28%), with Mg²⁺ and Cu²⁺ showing anxiolytic/depressant effects in the AC test.

Conclusions:

• All tested trace elements (Zn²⁺, Mg²⁺, Cu²⁺) effectively induced antinociceptive effects in both central and visceral pain models.
• The findings highlight the potential of these readily available and inexpensive trace elements as valuable adjunctive therapies for pain management.