The present findings corroborate similar findings by Hosseinzadeh (2011) who shown the apoptotic effect of the curcumin. We also reported that following generation of ROS, the mitochondrial membrane potential (MMP) decreased while the proapoptotic Bax manifestation increased. improved with the combination treatments in colon cancer cells. Finally, the combination of these flavonoids with doxorubicin improved the Bax/Bcl-2 percentage, caspase-3 manifestation and PARP cleavage. Summary: Combination of flavonoids with doxorubicin induces apoptosis and enhances effect on malignancy cells which might allow amelioration of side effects by dose lowering. Keywords: Doxorubicin, eupatorin, HT-29, salvigenin, SW948 Intro Study on biochemical activities of cellular pathways associated with colon cancer tumorigenic cells, the second leading cause of cancer-related deaths, may help to propose novel diagnostic and restorative methods (Pierini et al., 2008). Doxorubicin (DOXO) is an anthracycline antibiotic member of quinones class with many clinical indications in oncology. Despite holding a very potent characteristic, it is known to be accompanied by potential and fatal side effects actually at submicromolar concentration such as bone marrow toxicity, cumulative cardiotoxicity and stomatitis along with and presence of multidrug resistance (Wolf and Baynes, 2006). This, in turn, have the potential IU1-47 to offset its restorative benefits and limit its medical applications by superseded treatment or decrease the dose of DOXO (Wolf and Baynes, 2006). Over the past decades, converging avenues of study and quick dissemination of significant findings from diverse medical disciplines have greatly advanced treatments by natural products which show an extensive spectrum of biological activities (Miyata, 2007). Toxicity and resistance formation is a key challenge facing chemotherapy treatment which is definitely strongly suggested to be mitigated by natural product derived medicines (Ren et al., 2003). In particular, flavonoids are flower secondary metabolites that are ubiquitous in fruits, vegetables, nuts, seeds, and vegetation with a protecting effect against colon cancer progress (Ren et al., 2003; Arajo et al., 2011). Flavonoids which was analyzed here, is definitely eupatorin, one of the constituents of Salvia mirzayanii and salvigenin, one of the constituents of Salvia lachnocalyx and Salvia hydrangea (Moridi Farimani and Mazarei, 2014; Moghaddam et al., 1998). Apoptosis is one of the most important forms of cell death which is typically dysregulated in malignancy cell lines. Dysfunctional IU1-47 apoptosis prospects to malignancy treatment resistance making it an important pathway in malignancy restorative strategies (Bai and Wang, 2014). Apoptosis suppression alters the epithelium of the colorectal to carcinoma. Subsequently, tumor growth and cells become resistant to anticancer (Bai and Wang, 2014). Flavonoids which are able to induce apoptosis and have less side effects on normal cells can be considered as malignancy chemotherapeutic providers or can potentiate chemotherapy drug (Arajo et al., 2011). The principal objective of this study was to determine whether eupatorin and salvigenin, as natural non-toxic flavonoid products, inhibit the growth of colon cancer cells, and to see if these flavonoids can potentiate the non-effective dose of doxorubicin chemotherapy medicines. Materials and Methods Doxorubicin was purchased from Pfizer (perth) pty limited (Australia), and 3-(4, 5-dimethylthiazol-2yl)-2, 5-diphenyltetrazoliumbromide (MTT) and DAPI stain were from sigma Aldrich (Missouri, United States). Antibodies directed against, Bax, Bcl-2, Caspase-3, PARP and -actin were from Cell Signaling Technology (Danvers, Massachusetts, USA). Electrochemiluminescence (ECL) reagents were purchased from Amersham Bioscience (United LHCGR Kingdom) and Polyvinylidene fluoride (PVDF) from Millipore Corporation, Billerica, MA, USA. Tradition medium, penicillinCstreptomycin, and fetal bovine serum (FBS) were purchased from Gibco (Gibco, Grand Island, NY, USA). Flower material The aerial parts (leaves and blossoms) of Salvia mirzayanii, Salvia lachnocalyx and Salvia hydrangea were collected from different areas of Iran and recognized (Moridi Farimani and Mazarei, 2014; Moghaddam et al, 2010). Cell tradition condition HT-29, SW948 and HFFF-2 cells were purchased from National IU1-47 Cell standard bank of Iran, Tehran, Iran. These cells were cultivated in RPMI medium with 10% warmth inactivated Fetal Bovine Serum (FBS) and penicillin/streptomycin at 37C in 5 % CO2 humified incubator. The medium was changed every 2C3 days and subcultured again when cell human population denseness reached 70C80% confluence. Cells were seeded at an appropriate density relating to each experimental design. MTT assays of cell growth/viability Stock solutions of eupatorin and salvigenin were prepared in dimethyl sulfoxide (DMSO). The final concentration of the vehicle in the medium was always.