Antinociceptive and antiulcer activities of Pycnanthus angolensis

AbstractPycnanthus angolensis (Welw) Warb., Myristicaceae, is used in Nigeria folk medicine to treat complaints such as toothache, headache, sore throat, ulcers and wounds. The aim of the study was to investigate the antinociceptive and antiulcer activities of the stem bark extract of Pycnanthus angolensis. Acute toxicity was conducted with a single oral dose of 5 g/kg. Antinociceptive activity was evaluated in acetic acid-induced writhing, formalin and tail immersion tests in mice while antiulcer activity was evaluated in ethanol and indomethacin-induced models in rats. In acetic acid-induced writhing test, the extract (50, 100 and 150 mg/kg, p.o.), significantly reduced the number of writhes (46.75%, 57.28% and 75.69%) respectively, compared to control. The extract significantly (p < 0.001) reduced the time spent in licking the hind paw at both phases, in formalin test. In tail immersion test, significant antinociceptive effect was only observed with the dose of 150 mg/kg, with peak effect at 90 min (43.38%). There is no significant change in the spontaneous locomotor activity of animals in the open field. The extract prevented the gastric ulceration caused by ethanol and indomethacin treatments compared to control. The results showed that P. angolensis extract possesses antinociceptive and antiulcer activities supporting the traditional use for relieving pain and ulcers.

aqueous root extract of Aristolochia ringens [Vahl.] Aristolochiaceae inhibits chemically-induced inflammation in rodents

The potential of the aqueous root extract of Aristolochia ringens [AR] [10-100 mg/kg p.o] to inhibit inflammation induced by phlogistics was evaluated using the carrageenan and egg albumin induced rat paw oedema, formaldehyde induced arthritic inflammation and xylene induced mouse ear oedema models. AR [10-50 mg/kg] dose-dependently decreased rat paw oedema in the carrageenan and egg albumin induced inflammation, producing comparable inhibition of 57.1% and 65.6% to the 57.9% and 63.9% of indomethacin and diclofenac [10 mg/kg p.o] respectively at 50 mg/kg. AR [10-50 mg/kg] also dose dependently inhibited formaldehyde-induced arthritic paw oedema over the 10 day observation period, with a greater inhibition of 50% at 50 mg/kg than the 40.8% inhibition by diclofenac [10 mg/kg i.p]. AR [50 mg/kg] also produced greater inhibition of 84.78% than the 65.21% by dexamethasone [1 mg/kg] in xylene-induced ear oedema. Results show that the aqueous root extract of Aristolochia ringens possesses antiinflammatory activity