Antinociceptive effect of crude extract, fractions and three alkaloids obtained from fruits of Piper tuberculatum.

This study investigated the possible antinociceptive effect of the crude extract, fractions and pure compounds (three alkaloids) obtained from fruits of Piper tuberculatum JACQ. (Piperaceae) in acetic acid-induced visceral pain in mice. Oral administration of crude extract and fractions (CH(2)Cl(2), EtOAc, methanol and hexane) (3-300 mg kg(-1)) caused a dose-related and significant inhibition of the acetic acid-induced visceral nociceptive response.

Spinal antinociception evoked by the triterpene 3beta, 6beta, 16beta-trihydroxylup-20(29)-ene in mice: evidence for the involvement of the glutamatergic system via NMDA and metabotropic glutamate receptors.

The present study investigated the possible involvement of the glutamatergic and neurokinin systems in the antinociception caused by triterpene 3beta, 6beta, 16beta-trihydroxylup-20(29)-ene (TTHL) in mice. TTHL given by intraperitoneal (i.p.