The antinociceptive activity of Lac-FR in the writhing test. Abdominal constrictions induced by acetic acid (0.8% in saline) i.p. in mice previously treated (30 min) with control vehicle (10 ml/kg i.p.), indomethacin-positive control (10 mg/kg i.p.) or Lac-FR (100 and 300 mg/kg) (i.p. and p.o.). Results expressed as mean ± S.E.M. of 6 animals per experimental groups (ANOVA and Tukey’s test. ***p < 0.001).