Letter from the Editor

This study investigated the antinociceptive and anti‐inflammatory activities of the ethanolic extract (EESAl), fractions and the compound 8‐methoxylapachenol (8ML) obtained from the tubers of Sinningia allagophylla. Male Swiss mice were treated with EESAl (3–300 mg/kg) or vehicle by oral route (p.o.) 1 hr before the injection of formalin 2.5% or carrageenan (Cg) into the hind paw. EESAl (3–30 mg/kg) reduced the inflammatory phase of the nociceptive behaviour induced by formalin (around 65% for all doses). EESAl (3–300 mg/kg, p.o.) also reduced Cg‐induced mechanical hyperalgesia and oedema in a dose‐dependent fashion but did not change the hot‐plate latency or the motor performance of the animals. Oral administration of petroleum ether fraction (PE, 3 mg/kg), but not in the methanolic fraction (30 mg/kg), reduced both Cg‐induced oedema and hyperalgesia. Compound 8ML isolated from PE (1.8 mg/kg, p.o.) abolished Cg‐induced hyperalgesia but also did not change hot‐plate latency or motor performance of the animals. 8ML administration into the paw (0.75–750 pg) dose‐dependently reduced Cg‐induced hyperalgesia. 8ML (750 pg) also blocked the hyperalgesia induced by tumour necrosis factor (TNF‐α), interleukin‐1β (IL‐1β) and prostaglandin E₂ (PGE₂) but failed to change the hyperalgesia induced by cytokine‐induced neutrophil chemoattractant‐1 (CINC‐1) and dopamine (Dopa). These results suggest that EESAl has an important antinociceptive and anti‐inflammatory activity, the former one related, at least in part, to the reduction in the hyperalgesia. Similarly, 8ML reduced Cg‐induced oedema and mechanical hyperalgesia and seems to act in peripheral sites and on the prostaglandin rather than on the sympathetic component of the Cg‐inflammatory hyperalgesia.