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 hotplate 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-a), interleukin1b (IL-1b) and prostaglandin E 2 (PGE 2 ) 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.Gesneriaceae is a pantropical family of ornamental plants, with 135 genera, among these Sinningia. Sinningia genus comprises 68 species, distributed in South America, mainly in Brazil [1]. Sinningia allagophylla (Martius) Wiehler is a shrub species with the popular names of clove field, field-potato or potato-of-Partridge and is considered medicinal in Brazil. The tubers are used as an emollient and tonic, while the flowers and leaves are used as febrifuge, diuretic and cleanser [2].Studies on chemical composition of Sinningia species showed the presence of flavonoids on Sinningia cardinalis [3], ethylcyclohexane derivatives and anthraquinones in Sinningia speciosa [4] and anthraquinones and aromatic compounds with a new skeleton named aggregatins A-D in Sinningia aggregata [5]. In Sinningia allagophylla, lapachenol, 8ML, anthraquinones and naphthoquinones were found [6]. Naphthoquinones and anthraquinones are classes of natural compounds commonly associated with anti-inflammatory and antinociceptive properties. For example, vitamin K3 derivatives, plumbagin and emodin among others, are known naphthoquinones and anthraquinones, which share these properties [7][8][9].Traditionally, non-steroidal anti-inflammatory drugs are the class of compounds most widely used to t...

This study investigated the antinociceptive effects of the ethanolic extract (EEMO) obtained from Magnolia ovata (A.St.-Hil.) Spreng and N-acetylxylopine (AXyl), a stable derivative of xylopine in different models of nociception. The EEMO and AXyl inhibited the nociception induced by acetic acid in mice, in a dose-dependent manner with a maximal inhibition of 91 ± 9% and 50 ± 11%, respectively. Oral administration of EEMO or AXyl also significantly inhibited the inflammatory phase of formalin-induced nociception with maximal reduction of 87 ± 3.9% and 71 ± 10%, respectively. Confirming the effectiveness of the extract and the isolated compound in inflammatory responses, EEMO or AXyl inhibited carrageenan-induced mechanical allodynia with percentage of inhibition of 40 ± 6% for EEMO and 82 ± 8% for AXyl. Intraplantar injection of AXyl in the ipsilateral paw, but not in the contralateral paw, also reduced carrageenan-induced mechanical allodynia in mice. The response of the animals for maximal doses tested of EEMO and AXyl in the hot-plate or rota-rod models were not altered. These results show that the extract from M. ovata and the stable derivative AXyl possess analgesic properties towards inflammatory pain acting on peripheral sites.