Preliminary Evaluation of the Antinociceptive Activity of the Ethanolic Leaf Extract of Datura metel L. Collected in Misurata, Libya, Using the Hot Plate Test in Mice

Background: Datura metel L. (Solanaceae) is used in traditional medicine for pain relief, yet experimental data on plants growing in Libya are lacking. Objective: To make a preliminary assessment of the antinociceptive activity of the 75% ethanolic leaf extract of D. metel collected in Misurata, Libya, in mice. Methods: Dried leaf powder (35 g) was macerated in 175 mL of 75% ethanol for 72 h with continuous stirring, filtered and dried at 40 °C. Ten Swiss albino mice (n = 2 per group) were allocated to five groups: untreated control, normal saline, paracetamol (standard), and extract solutions of 10% and 20% (w/v), all given orally at 10 mL/kg. Reaction latency (paw licking, paw lifting or jumping) was recorded on a hot plate at 0, 60 and 90 min. One-way ANOVA with Tukey's post hoc test was used. Results: At 60 min, latency differed significantly among groups (p = 0.016). The 10% extract produced the longest latency (10.22 ± 0.005 s) compared with control (4.03 ± 0.65 s) and saline (4.88 ± 0.08 s) (both p < 0.05), but not compared with paracetamol (6.83 ± 1.53 s). The 20% extract (6.06 ± 0.59 s) was not different from the vehicle. No significant differences were found at 0 min (p = 0.111; plate at 30 °C) or at 90 min (p = 0.540), where the saline group also showed prolonged latencies. Conclusion: The 10% extract showed a short-lived, non-dose-dependent increase in hot plate latency at 60 min. Given the very small sample, the absence of motor and toxicity assessment and the high nominal dose, these findings are preliminary and hypothesis-generating only.