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The underground or the aerial part of Saururus chinensis (LOUR.) BAILL (Saururaceae) has been used as a folk medicine to treat edema, jaundice, and gonorrhea in Korea.1) Several constituents such as lignans, neolignans, 2) acyclic diterpenes, 3) aristolactams, 4) and particularly manassantin A and B 5) classified as dineolignans have been isolated from the genus Saururus. In addition, the constituent sauchinone and its stereoisomers, a phenylpropanoid (sarisan), lignans (galbacin and saucernetin), 6) diarylbutane lignans, 7) tetrahydrofuran-type sesquilignans, 8) and furanoditerpenes 9) were isolated from S. chinensis. It was reported that sauchinone, a lignan from S. chinensis, attenuated CCl 4 -induced toxicity in primary cultures of rat hepatocytes.10) Further, we previously demonstrated that the methanol extract and its active constituents, saucernetin-7 and saucernetin-8, isolated from S. chinensis inhibited the LPS-induced iNOS and COX-2 expression by blocking NF-kB activation. 11,12) Tumors are diverse and heterogeneous, but all share the ability to proliferate beyond the constraints limiting growth in normal tissue. Deregulated cell proliferation together with suppressed apoptosis and differentiation constitute the minimal commom platform upon which all neoplastic evolution occurs. Based on the understanding of tumor biology in respect to the kinetics of cell populations, two new strategies, induction of differentiation and apoptosis, have recently emerged in the fields of cancer chemoprevention and chemotherapy. Differentiation from malignant or premalignant cells into more mature or normal-like cells as well as apoptosis in multistep carcinogenesis are theoretically amenable to preventive cancer intervention. Thus, compounds capable of inducing differentiation are considered as candidate agents for the prevention and/or treatment of cancer. 13,14) The HL-60 cell line, derived from a patient with acute promyelocytic leukemia, provides a useful model system for studying the cellular and molecular events involved in the differentiation process.15) Certain compounds, known to be efficacious cancer preventative agents, such as interferon, 16) retinoids, 17) 1a,25-(OH) 2 D 3 18) are potent inducers of HL-60 cell differentiation, and appear to be clinically effective against myeloproliferative disorders. Thus, the strategy that manipulates HL-60 cell differentiation has been used as a valid model to discover potential cancer chemopreventive agents in preclinical evaluation. Thus, as a part of our screening program to evaluate the chemopreventive potential effect of natural compounds, we have investigated the effect of saucernetin-8, which was isolated from the underground parts of Saururus chinensis, on HL-60 growth and induction of differentiation. Various biochemical and morphological examinations performed in the present study indicated that saucernetin-8 contains the activity to induce HL-60 cell differentiation. Furthermore, we demonstrated that the expression of p21 CIP1 cyclin dependent kinase inhibito...

Background: Because the role and molecular mechanism of 2′-hydroxycinnamaldehyde (2′-HCA) in human leukemia need to be clarified, we provide detailed insights into the mechanism underlying the anti-proliferative properties of 2′-HCA in acute myeloid leukemia (AML).Methods: We performed MTT assay to examine the cytotoxic effect of 2′-HCA. 2′-HCA-induced apoptotic pathway was demonstrated by annexin V-FITC/ propidium iodide double staining, DAPI staining for DNA fragmentation detection, and western blot analysis. ROS generation, intracellular glutathione (GSH) level, and intracellular protein thiols (PSH) were detected to investigated the mechanism of 2′-HCA-related apoptosis. Xenograft animal model was used to evaluate anti-tumor activities of 2′-HCA.Results: The present study demonstrated that 2′-HCA induced apoptosis in human promyelocytic leukemia HL-60 cells through the activation of mitochondrial pathways. 2′-HCA also induced the activation of JNK and the pharmacological inhibition of JNK effectively prevented 2′-HCA-induced apoptosis and AP-1-DNA binding. In addition, 2′-HCA resulted in the accumulation of ROS and depletion of intracellular GSH and PSH in HL-60 cells. Xenograft mice inoculated with HL-60 leukemia cells demonstrated that the intraperitoneal administration of 2′-HCA inhibited tumor growth by increasing of TUNEL staining, the expression levels of nitrotyrosine, pro-apoptotic proteins, and PCNA protein expression. Conclusion: Our findings suggest that 2′-HCA induces apoptosis via the ROS-dependent JNK pathway and could be considered as a potential therapeutic agent for leukemia.