Effects of quercetin and verapamil on membrane potential in the liverwort Conocephalum conicum

Quercetin is a very common flavonoid widely distributed in many plants. The flavonoid intake has been linked to the prevention of human diseases inclu ding cancer. Flavonoids pos seas also a broad spectrum of effects on plants . Quercetin is involved in Ca2+ transport and metabolism. The present study was designed to check the effects of quercetin alone and in combination wi th verapamil on the resting and action potentials in the liverwort Conoceph alum conicum. The application of 59 . 10(-6) mol . dm(-3) quercetin caused an increase of action potential amplitudes. During the 3rd and 4th hour of treatment an increase by 20-22 % with respect to the control was observed. No changes were found in the resting potential in quercetin treated plants. Verapamil, a calcium channel inhibitor, caused gradual decrease of action potential amplitudes. Quercetin, when added together with verapamil, preven ted its inhibitory effect. Interactions between quercetin and Ca2+ transpor t are discussed.