Ml. Cornelio et al., Tracheal relaxant activity of cissaglaberrimine and trilobinine, two aporphinic alkaloids from Cissampelos glaberrima, PLANTA MED, 65(5), 1999, pp. 462-464
In the present work we studied the relaxant effect of two aporphinic alkalo
ids isolated from the roots barks of Cissampelos globerrima St. Hil. (Menis
permaceae), (+)-cissaglaberrimine (CGE; a tertiary alkaloid) and (+)-trilob
inine (TBE; a quaternary alkaloid). In guinea-pig tracheal preparations, CG
E and TBE reduced the spontaneous tone and inhibited the contractions induc
ed by carbachol and histamine. TBE was 6 times more potent than CGE in redu
cing the spontaneous tone and it was also 1.5 times more potent in antagoni
sing the effects of carbachol and histamine. The inhibitory effect of CGE i
n contractions induced by histamine was not attenuated in the presence of t
imolol (10 mu M). However, in the same experimental conditions, timolol alm
ost completely abolished the inhibitory effect of TBE. These results showed
that the relaxations induced by TBE were dependent on the activation of be
ta(2)-adrenoceptors, while the mechanism involved in relaxations induced by
CGE remains to be determined.