Avaliação das atividades antinociceptiva e antidepressiva do óleo essencial dos frutos de Schinus terebinthifolius e dos compostos (R)-(+)-limoneno e α-felandreno em roedores

Abstract

The objective of the present study was to evaluate the compounds (R)-(+)-limonene and α-phellandrene in models of sciatic nerve injury and intrathecal cytokine injection or gp120 in rodents. In the first article of our study, we have evaluated the antihyperalgesic and antidepressive activities of the 15-day oral treatment with S. terebinthifolius (100 mg/kg), limonene and phellandrene (10mg/kg) in sciatic nerve injury model in rats. Administration of the essential oil and compounds did not interfere with the locomotor activity of the animals and still significantly inhibited mechanical hyperalgesia and immobility, but only phellandrene was able to prevent increased sensitivity to cold. Based on the data, we can conclude that both the essential oil and the compounds exhibited antihyperalgesic and antidepressant activity. We also have investigated the antihyperalgesic potential of limonene in mice following intrathecal injection of gp120 or IL-1β or TNF-α. Animals were orally treated with limonene (10mg/kg) and after one hour received an injection of gp120 between the L5 and L6 vertebrae (50 and 300pg) or IL-1β (1000pg) or TNF-α (500ng). The results have demonstrated that limonene significantly reversed gp120-induced hyperalgesia after 3 hours of injection and also increased levels of IL-1β and IL-10 in the blood of the animals. Limonene was also able to significantly inhibit TNF-α and IL1β-induced mechanical hyperalgesia and modulate SOD and HSP90 expression in the spinal cord cells. Phellandrene (10mg/kg) compound was also tested, and results have demonstrated that intrathecal administration of gp120 or IL-1β significantly increased mechanical sensitivity and cold sensitivity in mice and that phellandrene was capable to reverse these effects after 2 and 3 hours. We have concluded limonene and phellandrene have antihyperalgesic activity through cytokine production modulation.