Résumé
Using calmodulin dependent cyclic neucleotide phosphodiesterase and dansyl-labeled calmodulin,honokiol's action on calmodulin is studied. It is found that honokiol inhibits the activity of cyclic neucleotide phosphodiesterase induced by stimulus of calmodulin. With the increasing of calmodulin concentration, the IC50 value was increased. In the presence of Ca2+, honokiol reduces the fluorescence intensity of dansyl-calmodulin, and makes the spectrumpeaked red. The results indicate that honokiol can combine with calmodulin in the presence of Ca2+ and antagonise the effect caused by calmodulin's stimulation upon the phosphodiesterase. In addition , honokiol may exert its effect on the basal activity of calmodulin dependent cyclic neucleotide phosphodiesterase.