Phytochemical analysis and antinociceptive activity of bitter ginger (Zingiber zerumbet) cultivated in Manaus/Amazonas

Abstract

The present work concerns the analgesic effects of zerumbona, obtained from Zingiber zerumbet L. Smith cultivated in Manaus/Amazonas. The compound has been studied for decades because it has potent cytotoxic activity against liver and prostate tumor cells, colon, and breast. The plant is rich in sesquiterpenes, glycosylated flavonoids that present important pharmacological activities; standing out cytotoxic activity against neoplastic cells of cancers. The objective of this study was to test the antinociceptive activity of zerumbone (ZER) using chemical and thermal nociception models, that is, writhing test induced by acetic acid and hot plate test. ZER administered orally and intraperitoneally produced significant and dose-dependent analgesic activity against the pain, acetic acid, formalin, and capsaicin models. In addition, ZER significantly increased the dormancy of the animals in the hotplate test pain model (49-540C). It was demonstrated that intraperitoneal (i.p.) and oral (p.o.) administration of ZER sesquiterpene in doses of 150 to 500 mg/kg i.p. and 250 to 1500 mg/kg p.o. produced significant dose-dependent inhibition of acetic acid-induced abdominal writhing, as compared to fentanest (20 µg/kg). At the same intraperitoneally and orally doses, the ZER produced significant dose-dependent latency-time increases in the hot-plate test relative to control. It was concluded that ZER exhibits both central and peripheral antinociceptive activity, indicating it to hold therapeutic potential for the discovery of new antinociceptive drugs as an alternative for the discovery of new drugs in the control of neurogenesi. The ZER exhibited similar efficacy and strength via both oral and intraperitoneally routes. ZER is the major essential oil component, a new sesquiterpene responsible for its nociceptive effect, when compared with other antinociceptive sesquiterpenes described in literature.