Antihyperalgesia induced by Heliopsis longipes extract.

Heliopsis longipes is an herbaceous plant found in Mexico. Heliopsis longipes is traditionally used for its analgesic and anesthetic properties. Plant extracts may represent a therapeutic advantage for the clinical treatment of pain. Therefore, the main objective of this study was to determine the possible antihyperalgesic effect produced by the Heliopsis longipes ethanolic extract (HLEE) in the Hargreaves model of thermal hyperalgesia in the mouse. HLEE was administrated systemically to mice and the antihyperalgesic effect was evaluated using the thermal hyperalgesia test. Oral Administration of HLEE produced a dose-dependent antihyperalgesic effect. Previously, it was reported that Heliopsis longipes extract was able to release GABA in mice temporal cortex slices. Therefore, it is likely that the antihyperalgesic effect observed in our study could result from GABA liberation and its inhibition of excessive excitation of nociceptive circuits in the thalamus and cortex evoked by tissue injury. Our results suggest that HLEE may represent a therapeutic advantage for the clinical treatment of inflammatory pain.