Figure 4; Dose response curves for the effect of morphine (1-10 mg kg-1 i.p.), diclofenac (10-100 mg kg-1 i.p.) and NLE (10-300 mg kg-1 p.o.) on the total nociceptive score for the first phase (a) and the second phase (b) of the rat formalin test. Each point represents mean ± S.E.M (n = 5).