Effects of Brugmansia arborea Extract and Its Secondary Metabolites on Morphine Tolerance and Dependence in Mice

Figure 1

Effects of different doses of Brugmansia arborea L. on the expression (a) and the acquisition (b) of tolerance to morphine-induced analgesia. Mice were treated twice daily for 5 days with either saline or 10 mg/kg morphine. BRU (0, 7.5, 15 and 30 mg/kg) was administered 30 min before each morphine injection (acquisition) or prior to the last morphine treatment (expression). Morphine antinociceptive effect (%MPE) was assessed on day 1 and day 5, as indicated. Significant differences: **𝑃<0.01, compared to control group; ⁺⁺𝑃<0.01, compared to related-morphine group on day 1; °°𝑃<0.01, compared to morphine group on day 5.

(a)

(b)