Involvement of K+ channels in the quercetin-induced inhibition of neuroblastoma cell growth

Abstract
The effects of the flavonoid quercetin on cell proliferation and voltage-dependent K+ current were studied on mouse neuroblastoma×glioma hybrid cells. In the presence of 1 % fetal calf serum, quercetin inhibited both cell proliferation and K+ current with effective doses inducing half-maximum effects of 10 μM and 70 μM respectively. Valinomycin (1 nM) antagonized 80 % of the growth-inhibitory effects of 10 μM quercetin. The results suggest that at least a part of the antiproliferative effect of quercetin is mediated by a K+ channel blockade. They further confirm a role for K+ channels in mitogenesis and cell proliferation.