Antinociceptive activity of the essential oil from Artemisia ludoviciana

Artemisia ludoviciana Nutt. is widely used in Mexico for treating gastrointestinal disorders and painful complaints. The antinociceptive action of the essential oil (EO) and its volatile composition were investigated. EO decreased both the first and second phases of formalin-induced nociception. The calculated median-effective dose (ED₅₀) was 269 mg/kg. The effectiveness of EO (ED₅₀= 25.9 mg/kg) for attenuating neurogenic pain was corroborated using the hot plate test. The antinociceptive action of EO was partially blocked by naloxone suggesting that its mode of action involved an opioid mechanism. On the other hand, volatile constituents extracted by hydrodistillation and those obtained by HS-SPME were established by GC-MS; the oil showed high amounts of (±)-camphor, γ-terpineol and borneol, and the major light volatile compounds identified by HS-SPME were 1,8-cineole and (±)-camphor. Altogether, these results support the long-term use of A. ludoviciana for treating painful complaints.