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

Figure 2

Effects of FA and FNA 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. FA (5.5 mg/kg) and FNA (24.5 mg/kg) were 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.

(a)

(b)