Arctium minus crude extract presents antinociceptive effect in a mice acute gout attack model.

Gout is a disorder that triggers a severe inflammatory reaction which generates episodes of intense pain and discomfort to the patient. Arctium minus (Hill) Bernh. (Asteraceae) is known as "burdock" and displays anti-inflammatory, antinociceptive, against rheumatic pain and radical-scavenging activities. Species of the genus Arctium have been used in assistant therapy of gout and other inflammatory processes. We investigated the antinociceptive and anti-edematogenic effects of the crude extract of A. minus seeds in an acute gout attack model induced by intra-articular injection of monosodium urate (MSU) crystals in adult male Swiss mice (25-30 g). The crude extract of A. minus (100 mg/kg, p.o.) reduced the mechanical allodynia induced by the injection of MSU (1.25 mg/site, i.a.) from 4 until 8 h after its administration. A. minus seeds crude extract prevented mechanical allodynia at doses of 30 and 100 mg/kg, but not 10 mg/kg. Allopurinol (10 µg/mL) and A. minus crude extract (10-300 µg/mL) inhibited the xanthine oxidase activity in vitro. The A. minus seeds crude extract did not cause adverse effects since did not change the toxicological parameters evaluated. A. minus crude extract can be used as an assistant therapy of gout pain, supporting its traditional use, without causing adverse effects.