**3.2 Acetic acid-induced writhing in mice**

The aqueous extract of *V. amygdalina* (50, 100, 200mg/kg i.p) exhibited a significant (P<0.05) antinocicetive activity against acetic acid-induced writhing in mice. 50 and 100 mg/kg oral doses exhibited a dose-dependent anti-nociception that progressively reduced over a period of 90 min post-treatment. However, at 120min the reduced anti-nociceptive activity increases again at these doses. The dose of 200 mg/kg on the other hand caused a total antinociception up to 120min. These results compared favorably with those of aspirin (100mg/kg i.p; Fig 1).

Fig. 1. Effect of aqueous extract of *V.amygdalina* leaves on acetic acid-induced writhing in mice for 5 min (NS, normal saline; Va, *V. Amygdalina*; ASA acetysalicylic acid). All data are presented as means ± S.E.M., n=5. The asterisk (\*) denotes, significance (p<0.05) between treated group and NS control
