en Cancer Biology Cancer Biology مقاله کامل Full Length/Original Article <strong>Background:</strong> This study aimed to investigate Levisticum officinale hydroalcoholic extract (<em>LOHE</em>) effect on both cGMP signaling pathway and phosphodiesterase 5 (<em>PDE5</em>) gene expression pattern and to examine the role of LOHE in apoptosis induction of MCF-7 and MDA-MB-468 cell lines. <strong>Methods</strong>: The half maximal inhibitory concentration (IC50) of <em>LOHE</em> was examined in both cell lines using the MTT assay. Using IC50 values of <em>LOHE</em> on both cells, the type of cell death was detected by flowcytometric analysis.&nbsp; The values of <em>PDE5</em> and cGMP were evaluated by real-time PCR and ELISA methods, respectively. <strong>Results</strong>: The IC50 values were measured as 150 &mu;g/ml for MDA-MB-468 and 200 &mu;g/ml for MCF-7. At 12 hour of treatment, a significant decrease in the <em>PDE5</em> expression and maximum increase in the amount of intracellular cGMP were observed (<em>p</em> < 0.05). However, these effects were more noticeable in MDA-MB-468 triple-negative cells. <strong>Conclusion:</strong> Our data suggest that <em>LOHE</em> extract could be a potential source for new strategies towards targeting both <em>PDE5</em> and cGMP signaling pathways. Apoptosis, Breast cancer, Levisticum, PDE5 280 286 http://ibj.pasteur.ac.ir/browse.php?a_code=A-10-1-757&slc_lang=en&sid=1 Marzieh Lotfian Sargazi 0000-0001-9825-249X No Cellular and Molecular Research Center Zahedan University of Medical Sciences, Zahedan, Iran Ramin Saravani 0000-0003-1941-3617 Yes Cellular and Molecular Research Center Zahedan University of Medical Sciences, Zahedan, Iran Ali Shahraki 0000-0002-9455-0243 No Department of Biology, Faculty of Science, University of Sistan and Baluchestan, Zahedan, Iran