Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 32
Filter
1.
Hum Exp Toxicol ; 40(12): 2048-2062, 2021 Dec.
Article in English | MEDLINE | ID: mdl-34053323

ABSTRACT

PURPOSE: The mechanism of cytotoxicity of silibinin on two human hepatocellular carcinoma (HCC) cell lines, HepG2 (p53 wild-type) and Hep3B cells (p53 null), is examined in relation with the induction of autophagy and phosphorylation of AMP-activated protein kinase (p-AMPK). MATERIALS AND METHODS: Levels of apoptosis in relation to the levels of autophagy and those of glycolysis-related proteins, glucose transporter 1/4 (Glut1/4) and hexokinase-II (HK2), in HepG2 and Hep3B cells were examined. RESULTS: Silibinin-induced apoptosis was incomplete for HCC cell death in that up-regulated autophagy and/or reduced level of glycolysis, which are induced by silibinin treatment, antagonized silibinin-induced apoptosis. Inhibition of autophagy with 3-methyl adenine (3MA) or blocking of AMP-activated protein kinase (AMPK) activation with Compound C (CC) enhanced silibinin-induced apoptosis. The results confirm that AMPK involved in autophagy as well as in glycolysis remaining with silibinin is responsible for attenuation of silibinin-induced apoptosis. Blocking of AMPK or autophagy contributes to the enhancement of silibinin's cytotoxicity to HepG2 and Hep3B cells. CONCLUSION: This study shows that incomplete apoptosis of HCC by silibinin treatment becomes complete by repression of autophagy and/or glycolysis.


Subject(s)
Antineoplastic Agents, Phytogenic/pharmacology , Carcinoma, Hepatocellular/drug therapy , Liver Neoplasms/drug therapy , Silymarin/pharmacology , AMP-Activated Protein Kinases/metabolism , Apoptosis/drug effects , Autophagy/drug effects , Carcinoma, Hepatocellular/metabolism , Cell Line, Tumor , Cell Proliferation/drug effects , Glycolysis/drug effects , Humans , Liver Neoplasms/metabolism , Phosphorylation/drug effects , Poly(ADP-ribose) Polymerases/metabolism
2.
J Pharmacol Exp Ther ; 331(1): 319-26, 2009 Oct.
Article in English | MEDLINE | ID: mdl-19638571

ABSTRACT

In Alzheimer's disease (AD), the deposition of amyloid peptides is invariably associated with oxidative stress and inflammatory responses. Silibinin (silybin), a flavonoid derived from the herb milk thistle, has potent anti-inflammatory and antioxidant activities. However, it remains unclear whether silibinin improves amyloid beta (Abeta) peptide-induced neurotoxicity. In this study, we examined the effect of silibinin on the fear-conditioning memory deficits, inflammatory response, and oxidative stress induced by the intracerebroventricular injection of Abeta peptide(25-35) (Abeta(25-35)) in mice. Mice were treated with silibinin (2, 20, and 200 mg/kg p.o., once a day for 8 days) from the day of the Abeta(25-35) injection (day 0). Memory function was evaluated in cued and contextual fear-conditioning tests (day 6). Nitrotyrosine levels in the hippocampus and amygdala were examined (day 8). The mRNA expression of inducible nitric-oxide synthase (iNOS) and tumor necrosis factor-alpha (TNF-alpha) in the hippocampus and amygdala was measured 2 h after the Abeta(25-35) injection. We found that silibinin significantly attenuated memory deficits caused by Abeta(25-35) in the cued and contextual fear-conditioning test. Silibinin significantly inhibited the increase in nitrotyrosine levels in the hippocampus and amygdala induced by Abeta(25-35). Nitrotyrosine levels in these regions were negatively correlated with memory performance. Moreover, real-time RT-PCR revealed that silibinin inhibited the overexpression of iNOS and TNF-alpha mRNA in the hippocampus and amygdala induced by Abeta(25-35). These findings suggest that silibinin (i) attenuates memory impairment through amelioration of oxidative stress and inflammatory response induced by Abeta(25-35) and (ii) may be a potential candidate for an AD medication.


Subject(s)
Amyloid beta-Peptides/toxicity , Memory Disorders/metabolism , Memory Disorders/prevention & control , Nitric Oxide Synthase Type II/biosynthesis , Peptide Fragments/toxicity , Tumor Necrosis Factor-alpha/biosynthesis , Animals , Antioxidants/pharmacology , Antioxidants/therapeutic use , Drug Synergism , Inflammation Mediators/therapeutic use , Male , Memory Disorders/chemically induced , Memory Disorders/enzymology , Mice , Mice, Inbred ICR , Nitric Oxide Synthase Type II/antagonists & inhibitors , Nitric Oxide Synthase Type II/genetics , RNA, Messenger/biosynthesis , Silybin , Silymarin/pharmacology , Silymarin/therapeutic use , Tumor Necrosis Factor-alpha/antagonists & inhibitors , Tumor Necrosis Factor-alpha/genetics , Tyrosine/analogs & derivatives , Tyrosine/biosynthesis , Up-Regulation/drug effects , Up-Regulation/genetics
3.
J Clin Invest ; 81(4): 1162-72, 1988 Apr.
Article in English | MEDLINE | ID: mdl-3258319

ABSTRACT

In addition to activating T and B lymphocytes, interleukin 1 (IL-1) induces several hematologic and metabolic changes typical of host responses to infection and injury. We now report a new biological property, namely, the induction of hypotension. Rabbits given a single intravenous injection of recombinant human IL-1-beta (5 micrograms/kg) rapidly developed decreased systemic arterial pressure, which reached the lowest levels after 50-60 min and slowly returned to pre-IL-1 values after 3 h. Associated with the hypotension, systemic vascular resistance and central venous pressure fell, while cardiac output and heart rate increased. These responses were prevented by ibuprofen given 15 min before the IL-1. A bolus injection of IL-1 followed by a 2-h infusion sustained the hypotension and was associated with leukopenia and thrombocytopenia. Ibuprofen given at the mid-point of the infusion reversed the changes in all hemodynamic parameters, but had no effect on the leukopenia or thrombocytopenia. Tumor necrosis factor (TNF) also induced a shock-like state in rabbits. When the dose of IL-1 or TNF was reduced to 1 microgram/kg, no hemodynamic changes were observed; however, the combination of these low doses of both cytokines resulted in a profound shock-like state including histological evidence of severe pulmonary edema and hemorrhage. Pretreatment with ibuprofen prevented the hemodynamic, leukocyte, and platelet changes induced by the low-dose cytokine combination, and ameliorated the pulmonary tissue damage. These results demonstrate that IL-1, like TNF, possesses the ability to induce hemodynamic and hematological changes typical of septic shock, and that the combination of IL-1 and TNF is more potent than either agent alone. These effects seem to require cyclooxygenase products, and suggest that intravenous cyclooxygenase inhibitors may be of therapeutic value in patients with IL-1/TNF-mediated shock.


Subject(s)
Ibuprofen/pharmacology , Interleukin-1/pharmacology , Shock/chemically induced , Tumor Necrosis Factor-alpha/pharmacology , Animals , Blood Pressure/drug effects , Drug Synergism , Hemodynamics/drug effects , Interleukin-1/antagonists & inhibitors , Leukocyte Count/drug effects , Lung/pathology , Platelet Count/drug effects , Rabbits , Shock/pathology , Tumor Necrosis Factor-alpha/antagonists & inhibitors
4.
J Clin Invest ; 73(5): 1312-20, 1984 May.
Article in English | MEDLINE | ID: mdl-6609169

ABSTRACT

Certain strains of Staphylococcus aureus associated with toxic shock syndrome elaborate material that induces human blood monocytes to secrete interleukin-1 (IL-1). IL-1 was detected both by its ability to cause fever in rabbits using the leukocytic pyrogen (LP) assay and by its mitogenic activity towards thymocytes in the so-called lymphocyte-activating factor (LAF) assay. Anti-human IL-1 prevents the manifestation of both activities. Filtrates of control strains of S. aureus manifest neither activity. Thus, culture filtrates derived from toxic shock syndrome (TSS)-associated strains cause biphasic fever in rabbits when injected intravenously. The fever lasts several hours. Plasma taken at the peak of the fever and injected into a second set of rabbits produces a brief monophasic fever typical of LP. Further, human monocytes release LP when incubated with TSS filtrates in vitro. The monocyte products also stimulate the proliferation of mouse thymocytes in the presence of phytohemagglutinin in a manner characteristic of LAF. A bacterial filtrate is much less effective without an intermediate incubation with monocytes. The stimulation of monocyte IL-1 production is easily quantified, provides a simple method of assaying the TSS toxin, and since it involves human cells, is directly relevant to the human disease. The assay was used to monitor the purification of TSS toxin. Only 0.1 ng/ml of the purified material is required to induce monocyte IL-1 production. It is thus more potent than endotoxin. In contrast to endotoxin, its effect is not blocked by polymyxin B. We conclude that in TSS the sudden fever and probably other components of the acute phase response may be attributed to a massive release of IL-1.


Subject(s)
Bacterial Toxins , Enterotoxins/pharmacology , Fever/etiology , Interleukin-1/biosynthesis , Superantigens , Animals , Enterotoxins/isolation & purification , Female , Humans , Interleukin-1/isolation & purification , Mice , Mice, Inbred C57BL , Monocytes/drug effects , Rabbits
5.
Trans R Soc Trop Med Hyg ; 99(8): 625-30, 2005 Aug.
Article in English | MEDLINE | ID: mdl-15927218

ABSTRACT

Neurocysticercosis (NCC) is one of the major causes of neurological disease in China. ELISA and immunoblotting using glycoproteins purified by preparative isoelectric focusing were used to detect human cysticercosis in Tongliao area, Inner Mongolia, China in 1998. Approximately 89% (39 of 44 inpatients and outpatients with suspected NCC at Tongliao City Hospital) were residents of Inner Mongolia. About 53% were male and 77% were of working age (18-59 years), and 32% were farmers. Immunoblotting and ELISA showed a high correlation. Of the 44 patients, 31 positive by cerebral computed tomography (CT) scan were confirmed serologically to have cysticercosis. In the ELISA, patients with no lesions by CT scan had lower OD values, similar to those of normal serum. These findings confirm that both ELISA and immunoblotting assays are sufficiently sensitive to detect asymptomatic or symptomatic cysticercosis patients.


Subject(s)
Cysticercosis/diagnosis , Cysticercosis/epidemiology , Neurocysticercosis/diagnosis , Taenia solium/immunology , Adolescent , Adult , Age Distribution , Animals , Antibodies, Helminth/blood , China/epidemiology , Enzyme-Linked Immunosorbent Assay , Female , Humans , Immunoblotting , Male , Middle Aged , Neurocysticercosis/complications , Neurocysticercosis/epidemiology , Sensitivity and Specificity , Sex Distribution
6.
J Leukoc Biol ; 43(3): 216-23, 1988 Mar.
Article in English | MEDLINE | ID: mdl-3257788

ABSTRACT

The concentrations of tumor necrosis factor (TNF) produced by human peripheral blood mononuclear cells (MNC) were measured using a radioimmunoassay (RIA) for human TNF. This was developed using a rabbit antiserum against human recombinant TNF (Hu rTNF), and Hu rTNF labeled with Na125I by a modification of the chloramine T method. This RIA does not detect human lymphotoxin, interleukin-1 alpha or beta, interleukin 2, interleukin 6, interferon alpha or gamma, granulocyte-macrophage-colony stimulating factor, and C5a des arg. A good correlation (r = 0.89) was found between the RIA and the cytolytic bioassay for TNF. The sensitivity of the RIA is between 3 and 78 pg/ml (median 11 pg/ml). The mean concentration of TNF in 24-h culture supernatants of human MNC exposed to different concentrations of lipopolysaccharide (LPS) was found to increase in dose-dependent fashion and then level off between 50 and 100 ng/ml. The concentrations of IL-1 beta and alpha detected by specific RIAs in these supernatants were between 0.2 and 19 ng/ml and 0.04 and 1 ng/ml, respectively. The amount of TNF produced by human MNC in vitro was determined in a cohort of 50 normal volunteers. Without exogenous stimuli, TNF concentrations were almost always below the detection limit; with 0.5 ng/ml LPS, the median concentration of TNF was 2 ng/ml, and with PHA the median was 3.8 ng/ml. In cultures performed in the presence of indomethacin significantly (p less than 0.005) more TNF was produced. Using this RIA, we could detect TNF in the circulation of mice injected with Hu rTNF. When plasma samples of patients with febrile illnesses were added directly to the RIA, TNF was not detectable, with the exception of patients with malaria. These studies demonstrate the range and sensitivity of LPS-induced and mitogen-induced production of immunoreactive TNF by human MNC in vitro without interference of similar cytokines in bioassays.


Subject(s)
Leukocytes, Mononuclear/analysis , Tumor Necrosis Factor-alpha/blood , Animals , Female , Humans , In Vitro Techniques , Interleukin-1/blood , Leukocytes, Mononuclear/metabolism , Lipopolysaccharides/pharmacology , Mice , Rabbits , Radioimmunoassay , Tumor Necrosis Factor-alpha/biosynthesis , Tumor Necrosis Factor-alpha/immunology
7.
J Invest Dermatol ; 93(4): 518-22, 1989 Oct.
Article in English | MEDLINE | ID: mdl-2674299

ABSTRACT

Interleukin-1 (IL-1) is a family of polypeptides that mediates a wide range of inflammatory and immune responses. In human skin, unstimulated keratinocytes produce a large amount of such cytokines. Although the precise role of IL-1 in the skin is unknown, there is experimental evidence supporting involvement of IL-1 in the pathogenesis of inflammatory skin diseases. In this study, we investigated in situ localization of IL-1 alpha and IL-1 beta in normal and psoriatic skin. Using polyclonal antibodies and the avidin-biotin peroxidase complex, we demonstrated the presence of both IL-1 alpha and IL-1 beta in normal and psoriatic formalin-fixed paraffin-embedded tissues. In both cases, IL-1 alpha was more prominent. However, the distribution of IL-1 alpha differed between normal and psoriatic skin. In normal skin, IL-1 alpha distribution was predominantly intercellular, whereas IL-1 alpha distribution was predominantly within the cytoplasm in psoriatic skin. These studies confirm that IL-1 alpha is the predominant form of IL-1 in the skin and provide further support for the hypothesis that IL-1 participates in the pathogenesis of psoriasis.


Subject(s)
Interleukin-1/analysis , Psoriasis/metabolism , Skin/metabolism , Adult , Aged , Child , Child, Preschool , Dose-Response Relationship, Immunologic , Female , Histocytochemistry , Humans , Immunoenzyme Techniques , Interleukin-1/classification , Male , Middle Aged , Psoriasis/pathology , Reference Values , Skin/pathology
8.
J Interferon Cytokine Res ; 16(12): 1079-88, 1996 Dec.
Article in English | MEDLINE | ID: mdl-8974012

ABSTRACT

On the basis of their relative hydropathy and alpha-helical structure, we prepared antibodies to four synthetic peptides with amino acid sequences homolgous to four hydrophilic, extracellular regions of the murine 80 kDa type I interleukin-1 receptor (IL-1RI). Antibodies to each of the four peptides recognized their specific immunogen. Human [125I]-IL-1 alpha or -beta was crosslinked to murine EL4 and D10S cells. Antiserum to peptide 150-166 precipitated the IL-1/IL-1R complex, whereas antibodies to peptide 66-84, 190-200, or 266-285 did not. Antibody to peptide 150-166 did not precipitate the type II IL-1R. Anti-IL-1RI150-166 blocked 71% of the binding of radiolabeled human IL-1 beta to EL4 cells and 50% of the binding to D10S cells. Using affinity-purified anti-IL-1RI150-166, we compared the ability of this antibody to inhibit the binding of murine or human IL-1 alpha to that of murine or human IL-1 beta. At a concentration of 20 ng/ml, affinity-purified anti-IL-1RI150-166 blocked 50% binding of murine IL-1 beta. At 1 microgram/ml, 90% blockage was observed. In contrast, no significant blockade of IL-1 alpha binding was observed at concentrations as high as 3 micrograms/ml of anti-IL-1RI150-166. The selective blockade of IL-1 beta forms was not due to differences in the affinities of these ligands for receptors on these cells. The antibody also blocked the binding of human IL-1 beta but not human IL-1 alpha to EL4 cells. The biologic activity of murine IL-1 beta but not IL-1 alpha on EL4 cells was also inhibited by this antibody. These data suggest (1) that antibody to a specific epitope on the extracellular domain interferes with the binding of IL-1 beta but not IL-1 alpha, (2) the differential inhibition of binding of IL-1 beta but not IL-1 alpha by anti-IL-1RI150-166 also blocks biologic activity, and (3) IL-1 alpha and IL-1 beta may transduce different signals by binding to separate loci on the IL-1RI.


Subject(s)
Antigen-Antibody Reactions , Interleukin-1/metabolism , Peptide Fragments/immunology , Protein Structure, Secondary , Receptors, Interleukin-1/immunology , Amino Acid Sequence , Animals , Binding Sites , Cell Line , Humans , Immunoglobulins/chemistry , Mice , Molecular Sequence Data , Molecular Weight , Precipitin Tests , Receptors, Interleukin-1/chemistry , Receptors, Interleukin-1/metabolism , Solubility , Tumor Cells, Cultured , Water/chemistry
9.
J Histochem Cytochem ; 32(6): 625-35, 1984 Jun.
Article in English | MEDLINE | ID: mdl-6427328

ABSTRACT

Mouse parotid gland and saliva were studied by histochemical, immunohistochemical, and activity measurements for carbonic anhydrase. Hansson 's histochemical reaction for carbonic anhydrase revealed positive enzyme activity in the parotid acinar cell cytoplasm and little or no reaction in the secretory granules. The luminal contents in all of the glandular duct systems also reacted positively, but the duct cells themselves were only weakly positive. Ultrastructural observations confirmed the light microscope histochemical localization and, in addition, revealed luminal content activity in intercellular ducts. Purified carbonic anhydrase isolated from mouse salivary glands was used to raise antibodies in rabbits. Localization of carbonic anhydrase by direct immunolabeling with fluorescein-coupled antibody and indirect immunoperoxidase labeling revealed enzyme localization on or in the acinar cell secretory granule membrane and not in the surrounding cytoplasm. The luminal contents of the intercalated and striated ducts were also strongly positive. Stimulation of salivary secretion with phenylephrine or pilocarpine increased the amount of carbonic anhydrase in saliva. Acetatazolamide and potassium cyanate inhibited carbonic anhydrase activity. Reasons underlying the discrepancy between the histochemical and immunolabeling localization of carbonic anhydrase are discussed. It is concluded that the parotid acinar cells of mice appear to be a significant source of carbonic anhydrase in saliva but its role is enigmatic.


Subject(s)
Carbonic Anhydrases/metabolism , Saliva/enzymology , Salivary Glands/enzymology , Animals , Cytoplasm/enzymology , Cytoplasmic Granules/enzymology , Female , Fluorescent Antibody Technique , Histocytochemistry , Immunoenzyme Techniques , Male , Mice , Mice, Inbred C3H , Mice, Inbred C57BL , Microscopy, Electron , Parotid Gland/enzymology , Salivary Glands/ultrastructure , Sublingual Gland/enzymology , Submandibular Gland/enzymology
10.
Z Naturforsch C J Biosci ; 53(5-6): 352-8, 1998.
Article in English | MEDLINE | ID: mdl-9679326

ABSTRACT

Tissue type (type 2) transglutaminase (TGase, EC 2.3.2.13) has been implicated in various cellular processes including cell death. In order to better understand the role of this enzyme in cell death, human melanocytic A375-S2 cells were treated with sphingosine, a cell-signaling mediator. During the rapid onset of cytotoxicity caused by this lipidic agent, tissue TGase was translocated from the cytoplasm to the cell nuclei. This observation was further remarked in relevance to its previously undescribed activity for DNA degradation. The DNA hydrolytic activity associated with tissue TGase was dependent on Mg2+ in contrast to the Ca2+ requirement for the classical cross-linking activity of TGase, and was inhibited by Zn2+. Based on the results shown here, we propose a novel aspect of tissue TGase in cell death.


Subject(s)
Cell Nucleus/enzymology , Sphingosine/toxicity , Transglutaminases/metabolism , Cell Death/drug effects , Cell Survival/drug effects , Cytoplasm/enzymology , DNA, Neoplasm/metabolism , Humans , Hydrolysis , Melanoma , Substrate Specificity , Tumor Cells, Cultured
11.
Pharmazie ; 59(4): 294-6, 2004 Apr.
Article in English | MEDLINE | ID: mdl-15125576

ABSTRACT

A new steroidal saponin, dioscoreside E (1), and a known compound, protodioscin (2), were isolated from an ethanol extract of the rhizomes of Dioscorea panthaica. The structure of 1 was established as 3-O-[bis-alpha-L-rhamnopyranosyl-(1 --> 2 and 1 --> 4)-beta-D-glucopyranosyl]-26-O-beta-D-glucopyranosyl-20(R)-methoxy-25(R)-furosta-5,22(23)-diene-3beta,26-diol, on the basis of spectral and chemical evidence. Compounds 1 and 2 showed cytotoxic activity against a panel of tumor cell lines.


Subject(s)
Antineoplastic Agents, Phytogenic/chemistry , Antineoplastic Agents, Phytogenic/pharmacology , Dioscorea/chemistry , Saponins/chemistry , Saponins/isolation & purification , Saponins/pharmacology , Steroids/chemistry , Steroids/isolation & purification , Steroids/pharmacology , Animals , Cell Line, Tumor , Drug Screening Assays, Antitumor , Humans , Hydrolysis , Magnetic Resonance Spectroscopy , Mice , Models, Molecular , Molecular Conformation , Spectrometry, Mass, Fast Atom Bombardment
13.
Br J Pharmacol ; 157(7): 1270-7, 2009 Aug.
Article in English | MEDLINE | ID: mdl-19552690

ABSTRACT

BACKGROUND AND PURPOSE: Accumulated evidence suggests that oxidative stress is involved in amyloid beta (Abeta)-induced cognitive dysfunction. Silibinin (silybin), a flavonoid derived from the herb milk thistle (Silybum marianum), has been shown to have antioxidative properties; however, it remains unclear whether silibinin improves Abeta-induced neurotoxicity. In the present study, we examined the effect of silibinin on the memory impairment and accumulation of oxidative stress induced by Abeta(25-35) in mice. EXPERIMENTAL APPROACH: Aggregated Abeta(25-35) (3 nmol) was intracerebroventricularly administered to mice. Treatment with silibinin (2, 20 and 200 mg.kg(-1), once a day, p.o.) was started immediately after the injection of Abeta(25-35). Locomotor activity was evaluated 6 days after the Abeta(25-35) treatment, and cognitive function was evaluated in a Y-maze and novel object recognition tests 6-11 days after the Abeta(25-35) treatment. The levels of lipid peroxidation (malondialdehyde) and antioxidant (glutathione) in the hippocampus were measured 7 days after the Abeta(25-35) injection. KEY RESULTS: Silibinin prevented the memory impairment induced by Abeta(25-35) in the Y-maze and novel object recognition tests. Repeated treatment with silibinin attenuated the Abeta(25-35)-induced accumulation of malondialdehyde and depletion of glutathione in the hippocampus. CONCLUSIONS AND IMPLICATIONS: Silibinin prevents memory impairment and oxidative damage induced by Abeta(25-35) and may be a potential therapeutic agent for Alzheimer's disease.


Subject(s)
Amyloid beta-Peptides/physiology , Memory Disorders/drug therapy , Neuroprotective Agents/pharmacology , Oxidative Stress/drug effects , Peptide Fragments/physiology , Alzheimer Disease/drug therapy , Amyloid beta-Peptides/toxicity , Animals , Exploratory Behavior/drug effects , Glutathione/metabolism , Hippocampus/metabolism , Lipid Peroxidation/drug effects , Male , Malondialdehyde/metabolism , Maze Learning/drug effects , Memory Disorders/chemically induced , Mice , Mice, Inbred ICR , Motor Activity/drug effects , Neuroprotective Agents/therapeutic use , Peptide Fragments/toxicity , Recognition, Psychology/drug effects , Silybin , Silymarin/pharmacology , Silymarin/therapeutic use
14.
J Asian Nat Prod Res ; 9(3-5): 245-52, 2007.
Article in English | MEDLINE | ID: mdl-17566917

ABSTRACT

Silymarin, derived from the milk thistle plant, Silybum marianum, has been traditionally used in the treatment of liver disease. Our previous study demonstrated that silymarin has an anti-apoptotic effect against UV irradiation. In this study, SIRT1, a human deacetylase that was reported to promote cell survival, was activated by silymarin (5 x 10(- 4) mol/L) in UV-irradiated human malignant melanoma, A375-S2 cells, followed by down-regulated expression of Bax and decreased release of cytochrome c. Cleavage of procaspase-3 and digestion of its substrates, the inhibitor of caspase-activated DNase (ICAD) and poly(ADP-ribose) polymerase (PARP), were also reduced. Consistent with its protective effect on UV-induced apoptosis, silymarin (5 x 10(- 4) mol/L) also increased G(2)/M phase arrest, possibly providing a prolonged time for efficient DNA repair. Consequently, that silymarin protected A375-S2 cell against UV-induced apoptosis was partially through SIRT1 pathway and modulation of the cell cycle distribution.


Subject(s)
Apoptosis/radiation effects , Cell Cycle/drug effects , Cytoprotection , Silymarin/pharmacology , Sirtuins/physiology , Cell Line, Tumor , Humans , Sirtuin 1 , Ultraviolet Rays
15.
J Asian Nat Prod Res ; 8(4): 335-43, 2006 Jun.
Article in English | MEDLINE | ID: mdl-16864444

ABSTRACT

Dracorhodin perchlorate, an anthocyanin red pigment, induces human premyelocytic leukemia HL-60 cell death through apoptotic pathway. Caspase -1, -3, -8, -9, and -10 inhibitors partially reversed the cell death induced by dracorhodin perchlorate. Caspase-3 and -8 were activated followed to the degradation of caspase-3 substrates, inhibitor of caspase-activated DNase (ICAD) and poly-(ADP-ribose) polymerase (PARP). Dracorhodin perchlorate up-regulated the expression ratio of mitochondrial proteins, Bax/Bcl-XL. The cell death was accompanied with phosphorylation of ERK, JNK and p38 MAPK and partially reduced by MEK inhibitor (PD98059), JNK MAPK inhibitor (SP600125) and p38 MAPK inhibitor (SB 203580). Taken together, dracorhodin perchlorate-induced apoptosis in HL-60 cells via up-regulation of Bax, activation of caspases and ERK/p38/JNK MAPKs.


Subject(s)
Antineoplastic Agents, Phytogenic/pharmacology , Apoptosis/drug effects , Benzopyrans/pharmacology , Antineoplastic Agents, Phytogenic/chemistry , Benzopyrans/chemistry , Caspases/metabolism , Dose-Response Relationship, Drug , Enzyme Activation , HL-60 Cells , Humans , MAP Kinase Kinase 4/metabolism , Mitogen-Activated Protein Kinase Kinases/metabolism , Molecular Structure , bcl-2-Associated X Protein/metabolism , p38 Mitogen-Activated Protein Kinases/metabolism
16.
Biochem Genet ; 16(7-8): 673-9, 1978 Aug.
Article in English | MEDLINE | ID: mdl-728060

ABSTRACT

We extracted the yellow melanin (phaeomelanin), black melanin (eumelanin), and mixed type of melanin from dorsal hair of dominant yellow (Ay/a), non-agouti (a/a), and agouti (A/A) mice, respectively. Spectrophotometric and fluorescence spectrophotometric analysis demonstrated that the yellow melanin was qualitatively distinct from the black melanin and that the agouti hair contained both types of pigment.


Subject(s)
Melanins/analysis , Mice/genetics , Animals , Genes, Dominant , Hair/analysis , Melanins/genetics , Species Specificity , Spectrometry, Fluorescence/methods
17.
Lymphokine Cytokine Res ; 11(4): 197-205, 1992 Aug.
Article in English | MEDLINE | ID: mdl-1420598

ABSTRACT

The two types of cell surface receptors for interleukin-1 (IL-1) are glycoproteins that contain N-glycosidic chains on their extracellular portions. To determine the role of glycosylation of the IL-1 receptor type I (IL-1RtI) in the binding and function of IL-1, we used four plant lectins and glycosidase treatment on two different T-cell lines (EL4-6.1 and D10S) and expressing high number of binding sites for IL-1. The lectins wheat germ agglutinin, phytohemagglutinin, and concanavalin A inhibited in a dose-response manner the IL-1-induced proliferation of D10S cells. Binding of IL-1 was blocked and radioactive IL-1 was displaced from these cells by these lectins. Specific sugars (GlcNAc, NeuAc, Gal-GlcNAc-Man, Man, or alpha-MeMan) did not themselves affect IL-1 binding but reversed the blocking effects of the lectins. The two cell lines differed in their responses to the lectin-mediated inhibition of IL-1 binding. Digestion by N-glycosidase significantly decreased the capacity of cells to bind IL-1, and reduced by approximately 20,000 D the M(r) of the IL-1RtI. Neuraminidase and O-glycanase treatment did not alter the binding of IL-1 to D10S or EL4-6.1 cells. This study demonstrates that glycosylation of the extracellular domain of the IL-1RtI is due to N-linked carbohydrates, that the degree of glycosylation can vary in cells of different lineage, and that this N-linked glycosylation appears to be essential for optimal binding and activity of IL-1 to its type I receptor.


Subject(s)
Interleukin-1/metabolism , Receptors, Interleukin-1/metabolism , Animals , Antibodies, Monoclonal , Binding, Competitive , Carbohydrate Conformation , Cell Line , Glycosylation , Interleukin-1/antagonists & inhibitors , Lectins , Mice , Protein Binding , T-Lymphocytes/metabolism
18.
Infect Immun ; 50(3): 765-70, 1985 Dec.
Article in English | MEDLINE | ID: mdl-3877692

ABSTRACT

Toxic shock syndrome toxin is already known to induce the production of interleukin-1 (IL-1) by preparations of monocytes and macrophages that are presumably contaminated with other types of cells. The response is enhanced by increasing the density of such monocytes, suggesting that the monocyte's response to toxic shock syndrome toxin may be augmented by its interaction with some other cell. Nevertheless, we now show that several human and murine macrophagelike cell lines (U937, J774, P388D1, and WEHI 3) produce IL-1 when exposed to toxic shock syndrome toxin, and therefore the basic response does not require the presence of cells of other lineages. The cultured cells generally produce less IL-1 than do monocytes, but considerably more IL-1 is induced from cells that have undergone a terminal differentiation as a result of exposure to 1 alpha,25-dihydroxyvitamin D3. High concentrations of cultured cels suppress the production of IL-1; this effect is apparently not due to long-lived inhibitors of IL-1 production or of IL-1 activity, but may be due to a short-lived inhibitor of production.


Subject(s)
Bacterial Toxins , Enterotoxins/pharmacology , Interleukin-1/biosynthesis , Macrophages/metabolism , Superantigens , Animals , Calcitriol/pharmacology , Cell Count , Cell Line , Female , Macrophages/cytology , Mercaptoethanol/pharmacology , Mice , Mice, Inbred BALB C , Molecular Weight , Monocytes/metabolism
19.
Immunopharmacology ; 49(3): 307-16, 2000 Sep.
Article in English | MEDLINE | ID: mdl-10996028

ABSTRACT

The effect of T-cell-independent B cell mitogen, a pectic polysaccharide, bupleuran 2IIc, from a medicinal herb, the roots of Bupleurum falcatum L. on interleukin 6 (IL-6) production of murine B cells and B cell lines was investigated in order to clarify the mechanism of enhanced immunoglobulin (Ig) secretion from B cells. Bupleuran 2IIc enhanced IgM secretion from highly purified murine normal B cells. When normal B cells from murine spleen were cultured with bupleuran 2IIc in the presence of anti-IL-6 neutralizing antibody, the enhanced IgM secretion by bupleuran 2IIc was reduced. When B cells were stimulated with bupleuran 2IIc, their IL-6 secretion and the transcription of IL-6 mRNA were enhanced. The enhanced IL-6 secretion by bupleuran 2IIc was also observed in B cell line, Y16 cell. When bupleuran 2IIc was digested with endo-alpha-(1-->4)-D-polygalacturonase, the resulting enzyme resistant carbohydrate portion, "ramified" region (PG-1) composed of rhamnogalacturonan core containing neutral sugar side chains showed potent IL-6 secretion-enhancing activity. These results suggest that the "ramified" region of bupleuran 2IIc stimulates the secretion of IL-6 as the active site, and the resulting IL-6 may partially contribute the enhancement of IgM secretion as an autocrine and/or paracrine mechanism.


Subject(s)
Adjuvants, Immunologic/pharmacology , B-Lymphocytes/drug effects , Drugs, Chinese Herbal/pharmacology , Interleukin-6/biosynthesis , Pectins/pharmacology , Plant Extracts/pharmacology , Plants, Medicinal/chemistry , Adjuvants, Immunologic/chemistry , Animals , B-Lymphocytes/metabolism , Bupleurum , Cell Line , Drugs, Chinese Herbal/chemistry , Female , Immune Sera/pharmacology , Immunoglobulin M/biosynthesis , Interleukin-6/immunology , Interleukin-6/metabolism , Mice , Mice, Inbred C3H , Pectins/chemistry , Plant Extracts/chemistry , Plant Roots/chemistry , Structure-Activity Relationship , Tumor Cells, Cultured
20.
J Clin Microbiol ; 38(12): 4439-44, 2000 Dec.
Article in English | MEDLINE | ID: mdl-11101577

ABSTRACT

Neurocysticercosis (NCC) caused by infection with the larvae of Taenia solium is an important cause of neurological disease worldwide. In order to establish an enzyme-linked immunosorbent assay (ELISA) for this infection using recombinant proteins, we carried out molecular cloning and identified four candidates as diagnostic antigens (designated Ag1, Ag1V1, Ag2, and Ag2V1). Except for Ag2V1, these clones could encode a 7-kDa polypeptide, and Ag2V1 could encode a 10-kDa polypeptide. All of the clones were very similar. Except for Ag2V1, recombinant proteins were successfully expressed using an Escherichia coli expression system. Immunoblot analysis of NCC patient sera detected recombinant proteins, but because reactivity to recombinant Ag1 was too weak, Ag1 was not suitable as an immunodiagnostic antigen. So, Ag1V1 and Ag2 were chosen as ELISA antigens, and the Ag1V1/Ag2 chimeric protein was expressed. Of 49 serum samples from NCC patients confirmed to be seropositive by immunoblot analysis, 44 (89.7%) were positive by ELISA. No assays of serum samples from patients with other parasitic infections recognized the Ag1V1/Ag2 chimeric protein. The Ag1V1/Ag2 chimeric protein obtained in this study had a high value for differential immunodiagnosis.


Subject(s)
Antigens, Helminth/genetics , Neurocysticercosis/diagnosis , Recombinant Fusion Proteins/immunology , Taenia/immunology , Amino Acid Sequence , Animals , Antigens, Helminth/immunology , Blotting, Southern , Cloning, Molecular , Enzyme-Linked Immunosorbent Assay , Molecular Sequence Data , Molecular Weight
SELECTION OF CITATIONS
SEARCH DETAIL