Antinociceptive activity of Ligusticum porteri preparations and compounds.

Context: The roots and rhizomes of Ligusticum porteri Coulter & Rose (Apiaceae) are widely used in Mexican folk medicine for several purposes, including painful complaints.

Objective: The main goal of this work was to demonstrate the analgesic action in mice of some preparations and major compounds from L. porteri.

Materials And Methods: The extracts, aqueous (AE) and organic (OE), the essential oil (EO) and major compounds (10-316 mg/kg) from L. porteri were evaluated as potential antinociceptive agents using the acetic acid-induced writhing and hot plate tests in ICR mice.

Results: All preparations tested exhibited significant antinociceptive effect in the two animal pain models selected. AE and EO were more effective in the writhing test while OE had a better effect in the hot-plate model. On the other hand, Z-ligustilide (1) provoked an increment in the latency period to the thermal stimuli in the hot-plate test at a dose of 31.6 mg/kg, and a decrease in the number of abdominal writhes at 10 mg/kg. Z-3-butylidenephthalide (2) induced a dose-dependent antinociceptive action in the hot-plate assay; this compound was also effective for controlling the pain provoked by chemical irritation at the doses of 10 and 31.6 mg/kg. Finally, diligustilide (3) inhibited the number of writhing responses at all doses tested but was inactive in the hot-plate model.

Conclusion: The present investigation provides in vivo evidence supporting the use of L. porteri to treat painful conditions in folk medicine.