Figure 1

The antinociceptive effect of i.p l-THP on formalin induced pain behavior.
(A) l-THP administration had no effect on the paw licking/biting behavior in the first phase of the formalin test. (B) However, the formalin induced pain behavior was significantly and dose dependently reduced by l-THP in the second phase of the formalin test as compared with control mice receiving i.p vehicle injection. (n = 8–12 per group) *P < 0.05 and **P < 0.01 as compared with that of the vehicle group.