Anti-inflammatory and antinociceptive activities of non-alkaloids fractions from Aconitum flavum in vivo

Aconitum flavum Hand.-Mazz., Ranunculaceae, has been used for the treatment of rheumatism, trau-matic injury in folk and clinical medicine, but the alkaloids has high toxicity. This study was designed to investigate the acute toxicity, anti-inflammatory and antinociceptive activities of non-alkaloids fractions from A. flavum in rodents. The anti-inflammatory activity was evaluated by inflammatory models of dimethylbenzene-induced ear vasodilatation and acetic acid-induced capillary permeability enhance-ment test in mice and carrageenan-induced paw edema in rats whereas the antinociceptive activity was evaluated using acetic acid-induced writhes, hot plate test and formalin test in mice. The result showed that the LD50 value of BtOH and EtOAc fractions could not be determined as no lethality was observed up to 40 g/kg (p.o.) in mice. BtOH fraction significantly decreased the dimethylbenzene-induced ear vasodilatation, carrageenan-induced paw edema and acetic acid-induced capillary permeability. EtOAc fraction only significantly attenuated paw edema and capillary permeability at the dose of 500 mg/kg. In antinociceptive test, BtOH and EtOAc fractions significantly reduced the writhing number evoked by acetic acid injection and the licking time in both phases of the formalin test. Meanwhile BtOH and EtOAc fractions had significant effect on hot plate test after 90 min. Our data indicate that the BtOH and EtOAc fractions of NAF are no toxicity. BtOH and EtOAc fractions not only inhibit inflammatory and peripheral inflammatory pain but also have central antinociceptive effect.