Kwon et al. BMC Cancer 2010, 10:392 http://www.biomedcentral.com/1471-2407/10/392 R E S E A R C H A R T I C L E Open Access Cinnamon extract induces tumor cell death through inhibition of NF B and AP1 Ho-Keun Kwon1, Ji-Sun Hwang1, Jae-Seon So1, Choong-Gu Lee1, Anupama Sahoo1, Jae-Ha Ryu1, Won Kyung Jeon2, Byoung Seob Ko2, Chang-Rok Im3, Sung Haeng Lee4, Zee Yong Park1, Sin-Hyeog Im1* Abstract Background: Cinnamomum cassia bark is the outer skin of an evergreen tall tree belonging to the family Lauraceae containing several active components such as essential oils (cinnamic aldehyde and cinnamyl aldehyde), tannin, mucus and carbohydrate. They have various biological functions including anti-oxidant, anti-microbial, anti- inflammation, anti-diabetic and anti-tumor activity. Previously, we have reported that anti-cancer effect of cinnamon extracts is associated with modulation of angiogenesis and effector function of CD8+ T cells. In this study, we further identified that anti-tumor effect of cinnamon extracts is also link with enhanced pro-apoptotic activity by inhibiting the activities NF B and AP1 in mouse melanoma model. Methods: Water soluble cinnamon extract was obtained and quality of cinnamon extract was evaluated by HPLC (High Performance Liquid Chromatography) analysis. In this study, we tested anti-tumor activity and elucidated action mechanism of cinnamon extract using various types of tumor cell lines including lymphoma, melanoma, cervix cancer and colorectal cancer in vitro and in vivo mouse melanoma model. Results: Cinnamon extract strongly inhibited tumor cell proliferation in vitro and induced active cell death of tumor cells by up-regulating pro-apoptotic molecules while inhibiting NF B and AP1 activity and their target genes such as Bcl-2, BcL-xL and survivin. Oral administration of cinnamon extract in melanoma transplantation model significantly inhibited tumor growth with the same mechanism of action observed in vitro. Conclusion: Our study suggests that anti-tumor effect of cinnamon extracts is directly linked with enhanced pro-apoptotic activity and inhibition of NF B and AP1 activities and their target genes in vitro and in vivo mouse melanoma model. Hence, further elucidation of active components of cinnamon extract could lead to development of potent anti-tumor agent or complementary and alternative medicine for the treatment of diverse cancers. Background Herbal medicines are plant-derived products which have been used as traditional folk medicine and food addi- tives. Recently their medicinal properties are under extensive investigation and become a major part of com- plementary and alternative medicines (CAMs). Their potency for treating different diseases has been reported including cancer, allergy and diabetes [1-4]. Cinnamomum cassia bark is the outer skin of an ever- green tall tree belonging to the family Lauraceae. Its extracts contain several active components such as * Correspondence: imsh@gist.ac.kr 1School of Life Sciences and Immune Synapse Research Center, Gwangju Institute of Science and Technology (GIST), 1 Oryong-dong, Puk-ku, Gwangju 500-712, Republic of Korea essential oils (cinnamic aldehyde and cinnamyl alde- hyde), tannin, mucus and carbohydrates [5,6]. They have various biological functions including anti-oxidant, anti- microbial, anti-inflammation, anti-diabetic effects [7-12], and anti-tumor activity [11,13]. However, for the devel- opment of cinnamon as CAMs for cancer treatment, further studies are necessary such as elucidation of working mechanisms and characterization of active compounds directly linked with anti-tumor activity. Cancers are the most life-threatening health problems in the world [14]. There have been many trials to treat cancers through modulation of anti-tumor immune response, apoptosis and anti-tumor proteins [15-18]. Tumor cells are generally resistant to apoptosis; hence selective killing of tumor cells by promoting apoptosis © 2010 Kwon et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.