Fig 3. Effects of naltrexone interacted with morphine or BHE thermal-induced antinociception within 2 h in the hot plate test.

Naltrexone (5 mg/kg, s.c.) was injected, 15 min prior to the administration of test samples. Control (10 ml/kg) or the BHE (200 mg/kg) was administered orally and morphine (10 mg/kg) subcutaneously. The time in seconds taken to lick the hind paw or jump was recorded. Cut-off time was 60 s. Values are expressed as mean ± SEM (n = 10). ***p < 0.001 vs. control (ANOVA followed by Dunnett's test). The independent t-test was used for comparison between two groups.