Effects of vario us receptor antagonists on the aqueous extract of bauhinia purpurea peripheral antinociceptive activity in mice / Khairiyah Anuar

The effects of various receptor antagonists on the antinociceptive activity of the Bauhinia purpurea leaves' aqueous extract (BPAE) were examined using the mouse abdominal constriction test. Crude dried BPAE was prepared in the doses of 300, 500 and 1000 mg/kg and administered subcutaneously 30 min prior to the test. From the antinociceptive profile obtained, all doses of BPAE exhibited significant (p< 0.05) antinociceptive activity with the 300 mg/kg BPAE producing an activity that is equivalent in strength when compared to the 150 mg/kg ASA. Based on the profile, the 500 mg/kg BP AE was chosen for the next study involving the various receptor antagonists. The mice were pretreated subcutaneously with different types of antagonists for 10 min followed by the 500 mg/kg BPAE administration and 30 min later subjected to the test. Based on the results obtained, naloxone (3 and 10 mg/kg), haloperidol ( 1 mg/kg), yohimbine (5 mg/kg) and reserpine (2 mg/kg) significantly reversed the 500 mg/kg BPAE antinociceptive activity. In conclusion, the BPAE antinociceptive activity is suggested to be involved in modulation of opiod, dopaminergic, a-adrenergic and monoaminergic receptor systems.