Purpose: To investigate the antinociceptive activity and acute toxicity of the ethanol extract of
Bromelia laciniosa
leaf.
Methods: A high performance liquid chromatography HPLC fingerprint of phenolic compounds was
developed. The antinociceptive effect of ethanol extract (Bl-EtOH) in mice was carried out using
chemical (writhing and formalin) and thermal (hot plate) models of nociception. The acute toxicity of the
extract was performed in mice using doses of 2.0 g/kg intraperitoneally and 5.0 g/kg orally. Blood was
removed for laboratory analysis of hematological and biochemical parameters.
Results: Bl-EtOH (100, 200 and 400 mg/kg, i.p.) reduced the number of writhing (91.80, 93.44 and
78.68 %, respectively) and the number of paw licks during the first (60.86, 62.84 and 66.79 %) and
second phase (91.93, 82.18 and 88.73 %) of the formalin test. Naloxone (1.5 mg/kg, i.p.) antagonized
the antinociceptive action of Bl-EtOH (100 mg/kg), and this finding suggests involvement of opioid
mechanism. The effect of Bl-EtOH on hot plate response provides a confirmation of its central effect.
Conclusion: B. laciniosa leaf extract has antinociceptive properties. Peripheral, and at least in part,
central mechanisms, may be involved in this antinociceptive effect. The ethanol leaf extract apparently
presents no significant toxicity.
