Isoalantolactone inhibits radiation-induced Mek and Erk1/2 protein phosphorylation in UMSCC-10A cells.

<p>(A) Whole-cell protein extracts were prepared from UMSCC-10A cells that were treated with radiation and isoalantolactone alone or in combination. Isoalantolactone at a dose of 5 μM was added to the cultured cells 16 hours prior to radiation 4 Gy exposure. The blot was probed with antibodies against Mek, Erk1/2, p-Mek, p-Erk1/2 and β-actin. (B) Mek and Erk1/2 protein expression relative to that of β-actin were assessed by densitometric analysis. p-Mek and p-Erk1/2 were expressed as the radio of p-Mek/total Mek and p-Erk1/2/total Erk1/2. ** <i>P</i><0.01, compared with the control or radiation alone.