Silibinin is a polyphenolic flavanoid derived from fruits and seeds of milk thistle (Silybum marianum). To investigate the effect and mechanism of silibinin on beta-isoproterenol-induced rat neonatal cardiac myocytes injury, the viability, the activation of lactate dehydrogenase (LDH) and the content of maleic dialdehyde (MDA) were chosen for measuring the degree of cardiac myocytes injury. Superoxide dismutase (SOD) activity, mitochondrial membrane potential (deltapsi) detected by flow cytometric analysis, and Western blotting analysis were applied to determine the related proteins. Silibinin protected isoproterenol-treated rat cardiac myocytes from death and significantly decreased LDH release and MDA production. Silibinin increased superoxide dismutase (SOD) activity, and increased mitochondrial membrane potential (deltapsi). Furthermore, the release of pro-apoptotic cytochrome c from mitochondria was reduced by silibinin. Silibinin increased the expression of anti-apoptotic Bcl-2 family protein Bcl-2, and up-regulation of SIRT1 inhibited the translocation of Bax from cytoplasm to mitochondria, which caused mitochondrial dysfunction and cell injury. Silibinin protects cardiac myocytes against isoproterenol-induced injury through resuming mitochondrial function and regulating the expression of SIRT1 and Bcl-2 family members.
Animals ; Animals, Newborn ; Blotting, Western ; Cardiotonic Agents ; isolation & purification ; pharmacology ; Cell Survival ; drug effects ; Cells, Cultured ; Dose-Response Relationship, Drug ; Isoproterenol ; toxicity ; L-Lactate Dehydrogenase ; metabolism ; Malondialdehyde ; metabolism ; Membrane Potential, Mitochondrial ; drug effects ; Milk Thistle ; chemistry ; Mitochondria, Heart ; drug effects ; metabolism ; physiology ; Myocytes, Cardiac ; drug effects ; metabolism ; pathology ; Plants, Medicinal ; chemistry ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Rats ; Rats, Sprague-Dawley ; Silymarin ; isolation & purification ; pharmacology ; Sirtuin 1 ; Sirtuins ; metabolism ; Superoxide Dismutase ; metabolism ; Up-Regulation ; bcl-2-Associated X Protein ; metabolism

To study the mechanism of downregulation of apoptosis by autophagy induced by oridonin in HeLa cells, the cell viability was measured by MTT method. DNA fragmentation was assayed by agarose gel electrophoresis. Autophagic and apoptotic ratio was determined by flowcytometric analysis. Protein expression was detected by Western blotting analysis. Oridonin induced both apoptosis and autophagy in HeLa cells. Apoptosis was upregulated by introduction of the inhibitor of autophagy, 3-methyladenine (3-MA). Addition of oridonin increased Bax/Bcl-2 expression ratio and cytochrome c, whereas the expression of SIRT-1 was decreased, and 3-MA pre-application enhanced these changes. Oridonin-induced autophagy antagonized apoptosis in HeLa cells through mitochondrial pathway.
Antineoplastic Agents, Phytogenic ; isolation & purification ; pharmacology ; Apoptosis ; drug effects ; Autophagy ; drug effects ; Blotting, Western ; Cytochromes c ; metabolism ; Diterpenes ; isolation & purification ; pharmacology ; Diterpenes, Kaurane ; isolation & purification ; pharmacology ; Flow Cytometry ; HeLa Cells ; Humans ; Isodon ; chemistry ; Plant Leaves ; chemistry ; Plants, Medicinal ; chemistry ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Sirtuin 1 ; Sirtuins ; metabolism ; bcl-2-Associated X Protein ; metabolism

A terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay was used to determine that apoptosis causes HeLa cell death induced by pseudolaric acid B. The c-Jun N-terminal kinase (JNK) inhibitor SP600125 decreased p53 protein expression during exposure to pseudolaric acid B. SP600125 decreased the phosphorylation of p53 during pseudolaric acid B exposure, indicating that JNK mediates phosphorylation of p53 during the response to pseudolaric acid B. SP600125 reversed pseudolaric acid B-induced down-regulation of phosphorylated extracellular signal-regulated protein kinase (ERK), and protein kinase C (PKC) was activated by pseudolaric acid B, whereas staurosporine, calphostin C, and H7 partly blocked this effect. These results indicate that p53 is partially regulated by JNK in pseudolaric acid B-induced HeLa cell death and that PKC participates in pseudolaric acid B-induced HeLa cell death.
Tumor Suppressor Protein p53/metabolism/*physiology ; Protein Kinase C/metabolism ; Phosphorylation ; JNK Mitogen-Activated Protein Kinases/*physiology ; Humans ; Hela Cells ; Diterpenes/*pharmacology ; DNA Fragmentation/drug effects ; Cell Death/*drug effects ; Anthracenes/pharmacology

BACKGROUND: Uterine cervix cancer is one of the diseases to damage female health and degrade quality of life. It has been a hot spot to decrease the side effects of radiotherapy and chemotherapy and anti-tumor medicine by using Chinese medicine in medical domain. In Europe, silymarin had been used to treat hepatitis. It had little toxic action and large contents in Chinese herb. Therefore, many researchers are studying its anti-tumor effects now.OBJECTIVE: To study the pharmacological mechanism of silymarin on human cervical cancer cell.DESIGN: The cells cultured in 10% serum medium served as negative control group in vitro.MATERIALS: The experiment was finished in the China-Japan Research Institute of Medical and Pharmaceutical Sciences in Shenyang Pharmaceutical University; Department of Pathological Science of Showa Medical UniversityMATERIASLS: Human cervical cancer cell (HeLa) is the preservative cell line of American ATCC in the Lab. The experiment was completed in the Cell Lab of China-Japan Research Institute of Medical and Pharmaceutical Sciences in Shenyang Pharmaceutical University from Feburary 2003 to July 2003.METHODS: HeLa cell death ratio was measured by methyl thiazol tetrazolium(MTT) assay. Cellular morphologic changes were observed by phase-contrast and fluorescence microscopy. Cell cycle distribution was analyzed by flow cytometry.MAIN OUTCOME MEASURES: The changes of cell death ratio and cell cycle distribution.RESULTS: Silymarin-induced HeLa cell death was relevant to the content of serum in medium. At the does of 80 μmol /L silymarin, the cell death ratio in serum-free group reached 85.27%. The cell death ratio in 5% and 10%serum groups was 35.53% and 7.71% respectively. Morphological changes of HeLa cells demonstrated that silymarin induced HeLa cell death through apoptotic pathway at lower concentration in serum-free condition. Flow cytometry analysis showed that silymarin induced 70. 04% cells death, most of which were in G0/G1 phase.CONCLUSION: Silymarin mainly induce G0/G1 phase HeLa cell death through apoptotic pathway in serum-free medium.

Interleukin-1beta (IL-1beta) is a pivotal proinflammatory cytokine. To investigate the mechanism of IL-1beta-induced cell death in human malignant melanoma A375-S2 cells, MTT assay, photomicroscopical observation, DNA agarose gel electrophoresis, radioimmunoassay and Western blot analysis were carried out. IL-1beta did not only induce nuclear condensation and DNA fragmentation, but also increased degradation of two substrates of caspase-3, poly ADP-ribose polymerase (PARP) and inhibitor of caspase-activated DNase (ICAD). Simultaneously, release of precursor of IL-1beta (pro-IL-1beta) and endogenous IL-1beta production were involved in the apoptotic process. IL-1beta enhanced the ratio of Bax/Bcl-2 and Bax/Bcl-xL expression and up-regulated apoptosis inducing factor (AIF) expression, which required the activation of downstream caspases. These results suggest that IL-1beta induces endogenous IL-1beta production, enhances cleavage of caspase downstream substrates and promotes mitochondria mediated apoptosis in A375-S2 cells.
Apoptosis/*drug effects ; Blotting, Western ; Caspase 1/metabolism ; Caspases/metabolism ; Cell Line, Tumor ; Cell Proliferation/drug effects ; Cell Survival/drug effects ; Comparative Study ; DNA Fragmentation/drug effects ; Deoxyribonucleases/metabolism ; Dose-Response Relationship, Drug ; Enzyme Activation/drug effects ; Humans ; Interleukin-1/biosynthesis/*pharmacology/physiology ; Interleukin-6/pharmacology ; Lymphotoxin/pharmacology ; Melanoma/metabolism/pathology/physiopathology ; Mitochondria/*physiology ; Poly(ADP-ribose) Polymerases/metabolism ; Proto-Oncogene Proteins c-bcl-2/biosynthesis ; Time Factors

BACKGROUNDThe role of extracellular signal-regulated kinase 1/2 (ERK1/2) in shikonin-induced HeLa cells apoptosis remains vague. This study was to investigate the activation of caspase pathways and the role of ERK1/2 in human cervical cancer cells, HeLa, by shikonin.

METHODSThe inhibitory effect of shikonin on the growth of HeLa cells was measured by MTT assay. Fluorescent microscopic analysis of apoptotic cells stained with 4',6'-oliiamiclino-2-phenylindole C (DAPI) and Hoechst 33258 was carried out. Caspase-3 and -8 activities were detected using caspase-3 substrate and caspase-8 substrate as substrates, respectively. The protein levels of ERK, p53 and p-ERK were determined by Western blot analysis.

RESULTSShikonin inhibited cell growth in a time- and dose-dependent manner. Caspase-3 and caspase-8 were activated in the apoptotic process and caspase inhibitors effectively reversed shikonin-induced apoptosis. Phosphorylation of ERK resulted in up-regulation of p53 expression, which was blocked by mitogen-activated protein kinase (MEK), inhibitor PD 98059.

CONCLUSIONShikonin induces HeLa cell apoptosis through the ERK, p53 and caspase pathways.

Apoptosis ; drug effects ; Caspases ; physiology ; Cell Proliferation ; drug effects ; DNA Damage ; Flavonoids ; pharmacology ; HeLa Cells ; Humans ; Mitogen-Activated Protein Kinase 1 ; metabolism ; Mitogen-Activated Protein Kinase 3 ; metabolism ; Naphthoquinones ; pharmacology ; Phosphorylation ; Tumor Suppressor Protein p53 ; analysis ; Up-Regulation

OBJECTIVETo study the mechanisms of oridonin-induced U937 cell apoptosis, and to examine the role of ERK MAPK.

METHODMTT, Hoechst 33258 staining, DNA agarose gel electrophoresis and Western blot analysis were used.

RESULTOridonin inhibited U937 cell growth in a time- and dose-dependent manner. Apoptotic bodies were found with Hoechst 33258 staining after treatment with 27 micromol x L(-1) oridonin. Simultaneously, ERK phosphorylation was significant. ERK inhibitor PD98059 partially blocked the growth-inhibitory effect as well as DNA fragmentation. The expression of antiapoptotic mitochondrial protein Bcl-XL decreased time-dependently, and that of proapoptotic protein Bax increased. However, PD98059 reversed the effect of oridonin on Bcl-XL and Bax.

CONCLUSIONOridonin induces U937 cell apoptosis through activation of ERK and alteration of the ratio of Bax/Bcl-XL.

Apoptosis ; drug effects ; Cell Proliferation ; drug effects ; DNA Fragmentation ; drug effects ; Diterpenes ; administration & dosage ; isolation & purification ; pharmacology ; Diterpenes, Kaurane ; administration & dosage ; isolation & purification ; pharmacology ; Dose-Response Relationship, Drug ; Extracellular Signal-Regulated MAP Kinases ; antagonists & inhibitors ; metabolism ; Flavonoids ; pharmacology ; Humans ; Isodon ; chemistry ; Phosphorylation ; Plants, Medicinal ; chemistry ; U937 Cells ; bcl-2-Associated X Protein ; metabolism ; bcl-X Protein ; metabolism

BACKGROUNDWe have reported that norcantharidin (NCTD) induces human melanoma A375-S2 cell apoptosis and that the activation of caspase and the mitochondrial pathway are involved in the apoptotic process. This study aimed at investigating the roles of mitogen-activated protein kinase (MAPK) and protein kinase C (PKC) in A375-S2 cell apoptosis induced by NCTD.

METHODSWe assessed the effects of NCTD on cell growth inhibition using the 3-(4,5-dimethylthiazol-2-yl)-2,5-dipheyltetrazolium bromide (MTT) assay, DNA fragmentation (DNA agarose gel electrophoresis), and MAPK protein levels (Western blot analysis) in A375-S2 cells. Photomicroscopic data were also collected.

RESULTSThe NCTD inhibitory effect on A375-S2 cells was partially reversed by MAPK and PKC inhibitors. The expression of phosphorylated JNK and p38 also increased after the treatment with NCTD, and inhibitors of c-Jun NH2-terminal kinase (JNK) and p38 (SP600125 and SB203580, respectively) had significant inhibitory effects on the upregulation of phosphorylated JNK and p38 expression. Simultaneously, the PKC inhibitor staurosporine blocked the upregulation of phosphorylated JNK and phosphorylated p38, but had little effect on extracellular signal-regulated kinase (ERK) expression.

CONCLUSIONThese results suggest that the activation of JNK and p38 MAPK promotes the process of NCTD-induced A375-S2 cell apoptosis and that PKC plays an important regulation role in the activation of MAPKs.

Antineoplastic Agents ; pharmacology ; Apoptosis ; drug effects ; Bridged Bicyclo Compounds, Heterocyclic ; pharmacology ; Cell Line, Tumor ; DNA Fragmentation ; drug effects ; Enzyme Activation ; Humans ; Melanoma ; drug therapy ; pathology ; Mitogen-Activated Protein Kinases ; physiology ; Protein Kinase C ; antagonists & inhibitors ; physiology ; Staurosporine ; pharmacology

OBJECTIVETo study the mechanisms of pseudolaric acid B-induced apoptosis on A375-S2 cells.

METHODMTT, fluorescence microscope observation, DNA agarose gel electrophoresis and Western blot analysis wereused.

RESULTPseudolaric acid Binduces A375-S2 cell apoptosis in a time and dose-dependent manner. Apoptotic bodies and DNA ladder were observed in 5 micromol x L(-1) pseudolaric acid B-treated A375-S2 cells for 36 h. The expression of Bcl-2, Bcl-xL and ICAD was reduced time dependently, whereas the expression of Bax was increased.

CONCLUSIONThe major cause of pseudolaric acid B induced cytotoxicity on A375-S2 cells was apoptosis. Mitochondria proteins and ICAD might be involved in the apoptotic pathways of pseudolaric acid B-treated A375-S2 cells.

Apoptosis ; drug effects ; Apoptosis Regulatory Proteins ; Cell Line, Tumor ; Diterpenes ; isolation & purification ; pharmacology ; Dose-Response Relationship, Drug ; Humans ; Melanoma ; metabolism ; pathology ; Pinaceae ; chemistry ; Proteins ; metabolism ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; bcl-2-Associated X Protein ; bcl-X Protein

AIMTo study the role of PKC in evodiamine-induced A375-S2 cell death.

METHODSRatio of apoptosis induced by evodiamine was determined by TUNEL assay. MTT assay was carried out to assess cytotoxic effect of evodiamine. The influence on expression of ERK, phospho-ERK and Bcl-2 was detected by Western blotting analysis.

RESULTSTUNEL assay indicated that apoptosis was the type of A375-S2 cell death induced by evodiamine treatment for 24 h. Both staurosporine (inhibitor of PKC) and PD98059 (inhibitor of ERK) cooperated with evodiamine to further induce A375-S2 cell death. Evodiamine inhibited PKC activity, down-regulated the expression of ERK, phospho-ERK and Bcl-2, and staurosporine was capable of augmenting these effects induced by evodiamine.

CONCLUSIONPKC lies upstream and exhibits regulatory effect on ERK and Bcl-2 in evodiamine-induced cell death.

Apoptosis ; drug effects ; Cell Line, Tumor ; Evodia ; chemistry ; Extracellular Signal-Regulated MAP Kinases ; antagonists & inhibitors ; metabolism ; Flavonoids ; pharmacology ; Humans ; Melanoma ; pathology ; Plant Extracts ; isolation & purification ; pharmacology ; Plants, Medicinal ; chemistry ; Protein Kinase C ; antagonists & inhibitors ; metabolism ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Quinazolines ; isolation & purification ; pharmacology ; Staurosporine ; pharmacology