ABSTRACT
CONTEXT: Nardostachys chinensis Batalin (Valerianaceae) has been used in Korean traditional medicine to elicit stomachic and sedative effects. However, the anti-leukemic activities of N. chinensis have not been well examined. OBJECTIVE: To investigate the effect of N. chinensis on differentiation and proliferation in the human promyelocytic leukemic HL-60 cells. MATERIALS AND METHODS: The dried roots and stems of N. chiensis are extracted using hot water and then freeze-dried. The yield of extract was 12.82% (w/w). The HL-60 cells were treated with 25-200 µg/ml of N. chinensis for 72 h or 100 µg/ml of N. chinensis for 24-72 h. RESULTS: Nardostachys chinensis significantly inhibited cell viability dose dependently with an IC50 of 100 µg/ml in HL-60 cells. Nardostachys chinensis induced differentiation of the cells as measured by reduction activity of NBT and expression of CD11b but not of CD14 as analyzed by flow cytometry, which indicates a differentiation toward the granulocytic lineage. Nardostachys chinensis also induced growth inhibition through G0/G1 phase arrest in the cell cycle of HL-60 cells. Among the G0/G1 phase in the cell cycle-related protein, the expression of cyclin-dependent kinase (CDK) inhibitor p27(Kip1) was increased in N. chinensis-treated HL-60 cells, whereas the expression levels of CDK2, CDK4, CDK6, cyclin D1, cyclin D3, cyclin E, and cyclin A were decreased. Interestingly, N. chinensis markedly enhanced the binding of p27(Kip1) with CDK2 and CDK6. DISCUSSION AND CONCLUSION: This study demonstrated that N. chinensis is capable of inducing cellular differentiation and growth inhibition through p27(Kip1) protein-related G0/G1 phase arrest in HL-60 cells.
Subject(s)
Cyclin-Dependent Kinase Inhibitor p27/biosynthesis , G1 Phase/drug effects , Granulocytes/drug effects , Growth Inhibitors/pharmacology , Nardostachys , Plant Extracts/pharmacology , Resting Phase, Cell Cycle/drug effects , Cell Differentiation/drug effects , Cell Differentiation/physiology , G1 Phase/physiology , Granulocytes/metabolism , Growth Inhibitors/isolation & purification , HL-60 Cells , Humans , Leukemia, Promyelocytic, Acute/metabolism , Plant Extracts/isolation & purification , Plant Roots , Plant Stems , Resting Phase, Cell Cycle/physiologyABSTRACT
The underground parts of Nardostachys chinensis (N. chinensis), which belongs the genus Valerianaceae, have been used as sedative and analgesic agents in traditional Korean medicine for centuries. The mitogen-activated protein kinases (MAPKs) are serine/threonine kinases involved in the regulation of various cellular responses, such as cell proliferation, differentiation and apoptosis. Protein kinase C (PKC) plays a key role in the regulation of proliferation and differentiation. In this study, we investigated the signaling pathways involved in the differentiation of the HL-60 human leukemic cells induced by N. chinensis extract. Treatment with N. chinensis extract resulted in the activation of the extracellular signal-regulated kinase (ERK) pathway and induced the differentiation of HL-60 cells into granulocytes. The activation of p38 MAPK was also observed 24 h after treatment; however, the activation of c-Jun N-terminal kinase (JNK) was unaffected. Treatment with an inhibitor of ERK (PD98059) blocked the nitrotetrazolium blue chloride (NBT) reducing activity and CD11b expression in the N. chinensis-treated HL-60 cells, whereas treatment with an inhibitor of p38 MAPK (SB203580) had no significant effect on NBT reducing activity and CD11b expression. In addition, N. chinensis extract increased PKC activity and the protein levels of PKCα, PKCßI and PKCßII isoforms, without a significant change in the protein levels of the PKCγ isoform. PKC inhibitors (GF 109203X, chelerythrine and H-7) inhibited the differentiation of HL-60 cells into granulocytes, as well as ERK activation in the N. chinensis-treated HL-60 cells. These results indicate that the PKC and ERK signaling pathways may be involved in the induction, by N. chinensis extract, of the differentiation of HL-60 cells into granulocytes.
Subject(s)
Cell Differentiation/drug effects , Leukemia, Promyelocytic, Acute/drug therapy , Plant Extracts/pharmacology , Protein Kinase C/biosynthesis , Gene Expression Regulation, Neoplastic/drug effects , Granulocytes/drug effects , HL-60 Cells , Humans , Leukemia, Promyelocytic, Acute/pathology , MAP Kinase Signaling System/drug effects , Nardostachys/chemistry , Plant Extracts/chemistry , Protein Isoforms/biosynthesisABSTRACT
OBJECTIVE: This study was performed to analyze the single-dose toxicity of D-amino acid oxidase (DAAO) extracts. METHODS: All experiments were conducted at the Korea Testing & Research Institute (KTR), an institution authorized to perform non-clinical studies, under the regulations of Good Laboratory Practice (GLP). Sprague-Dawley rats were chosen for the pilot study. Doses of DAAO extracts, 0.1 to 0.3 cc, were administered to the experimental group, and the same doses of normal saline solution were administered to the control group. This study was conducted under the approval of the Institutional Animal Ethics Committee. RESULTS: In all 4 groups, no deaths occurred, and the LD50 of DAAO extracts administered by IV was over 0.3 ml/kg. No significant changes in the weight between the control group and the experimental group were observed. To check for abnormalities in organs and tissues, we used microscopy to examine representative histological sections of each specified organ, the results showed no significant differences in any organs or tissues. CONCLUSION: The above findings suggest that treatment with D-amino acid oxidase extracts is relatively safe. Further studies on this subject should be conducted to yield more concrete evidence.
