A spider derived peptide, PnPP-19, induces central antinociception mediated by opioid and cannabinoid systems

• Published in: The journal of venomous animals and toxins including tropical diseases 2016-12, Vol.22 (1), p.34-34, Article 34
• Main Authors: da Fonseca Pacheco, Daniela, Freitas, Ana Cristina Nogueira, Pimenta, Adriano Monteiro C, Duarte, Igor Dimitri Gama, de Lima, Maria Elena
• Format: Article
• Language: English
• Subjects: Animals; CB1 receptor; CB2 receptor; Central antinociception; Dosage and administration; Drug dosages; Drug withdrawal; Experiments; Narcotics; Nervous system; Opioids; Peptide PnPP-19; Peptides; Phoneutria nigriventer; Spiders; TOXICOLOGY; Toxins; TROPICAL MEDICINE; Venom; δ-opioid receptor; μ-opioid receptor
• ISSN: 1678-9199; 1678-9199
• DOI: 10.1186/s40409-016-0091-6

Some peptides purified from the venom of the spider have been identified as potential sources of drugs for pain treatment. In this study, we characterized the antinociceptive effect of the peptide PnPP-19 on the central nervous system and investigated the possible involvement of opioid and cannabinoid systems in its action mechanism. Nociceptive threshold to thermal stimulation was measured according to the tail-flick test in Swiss mice. All drugs were administered by the intracerebroventricular route. PnPP-19 induced central antinociception in mice in the doses of 0.5 and 1 μg. The non-selective opioid receptor antagonist naloxone (2.5 and 5 μg), μ-opioid receptor antagonist clocinnamox (2 and 4 μg), δ-opioid receptor antagonist naltrindole (6 and 12 μg) and CB receptor antagonist AM251 (2 and 4 μg) partially inhibited the antinociceptive effect of PnPP-19 (1 μg). Additionally, the anandamide amidase inhibitor MAFP (0.2 μg), the anandamide uptake inhibitor VDM11 (4 μg) and the aminopeptidase inhibitor bestatin (20 μg) significantly enhanced the antinociception induced by a low dose of PnPP-19 (0.5 μg). In contrast, the κ-opioid receptor antagonist nor-binaltorphimine (10 μg and 20 μg) and the CB receptor antagonist AM630 (2 and 4 μg) do not appear to be involved in this effect. PnPP-19-induced central antinociception involves the activation of CB cannabinoid, μ- and δ-opioid receptors. Mobilization of endogenous opioids and cannabinoids might be required for the activation of those receptors, since inhibitors of endogenous substances potentiate the effect of PnPP-19. Our results contribute to elucidating the action of the peptide PnPP-19 in the antinociceptive pathway.