Asarum sieboldii, as a medicinal and food plant, has been used to treat pain and inflammation in
traditional Korean medicine. In the present study, it was analyzed the effects of water extracts of A.
sieboldii (WEAS) on the growth and apoptosis of human lung carcinoma (A549 and NCI-H460) and
colon cancer (HT29) cell lines. Treatment with WEAS in A549 cells inhibited the cell growth and
induced apoptosis in a dose-dependent manner as measured by MTT assay, however NCI-H460 and HT29
cells exhibited relatively weak anti- proliferative activities to WEAS. RT-PCR and Western blot data
revealed that the anti-proliferative effect of WEAS in A549 cells was associated with a dose-dependent
up-regulation of cyclin-dependent kinase inhibitor p21 (WAF1/CIP1) protein in a tumor suppressor
p53-independent fashion. However the levels of proliferating cell nuclear antigen (PCNA) mRNA and
protein expression were markedly down-regulated by WEAS treatment. It was also found WEAS
treatment decreased the levels of cyclooxygenase (COX)-2 and inducible nitric oxide synthease (iNOS)
expression without significant changes in the expression of COX-1. Though further studies will be needed
to identify the active compounds that confer the anti-cancer activity of WEAS, the present findings
provide important new insights into the possible molecular mechanisms of the anti-cancer activity of
A. sieboldii.

Keywords: Asarum sieboldii, p21, PCNA, COX-2, iNOS