No abstract available.
Chromans ; Thiazolidinediones

Rho iso-alpha acids-rich extract (RIAA) from Humulus lupulus (hops) and proanthocyanidins-rich extracts (PAC) from Acacia nilotica exert anti-inflammatory and anti-diabetic activity in vitro and in vivo. We hypothesized that a combination of these two extracts would exert enhanced effects in vitro on inflammatory markers and insulin signaling, and on nonfasting glucose and insulin in db/db mice. Over 49 tested combinations, RIAA:PAC at 5:1 (6.25 microg/mL) exhibited the greatest reductions in TNFalpha-stimulated lipolysis and IL-6 release in 3T3-L1 adipocytes, comparable to 5 microg/mL troglitazone. Pretreatment of 3T3-L1 adipocytes with this combination (5 microg/mL) also led to a 3-fold increase in insulin-stimulated glucose uptake that was comparable to 5 microg/mL pioglitazone or 901 microg/mL aspirin. Finally, db/db mice fed with RIAA:PAC at 5:1 (100 mg/kg) for 7 days resulted in 22% decrease in nonfasting glucose and 19% decrease in insulin that was comparable to 0.5 mg/kg rosiglitazone and better than 100 mg/kg metformin. RIAA:PAC mixture may have the potential to be an alternative when conventional therapy is undesirable or ineffective, and future research exploring its long-term clinical application is warranted.
Acacia ; Adipocytes ; Animals ; Aspirin ; Chromans ; Glucose ; Humulus ; Insulin ; Insulin Resistance ; Interleukin-6 ; Lipolysis ; Metformin ; Mice ; Thiazolidinediones

Animals ; Antineoplastic Agents ; therapeutic use ; Chromans ; therapeutic use ; Diethylnitrosamine ; Ligands ; Liver Neoplasms, Experimental ; chemically induced ; drug therapy ; Male ; PPAR gamma ; biosynthesis ; genetics ; Rats ; Rats, Wistar ; Thiazolidinediones ; therapeutic use

PURPOSE: Troglitazone (TRO), a PPAR-gamma agonist, can reduce heat shock protein (HSP) 70 and increase the antioxidant enzymes, such as superoxide dismutase (SOD) and catalase, which might affect thermal sensitivity. Here, we investigated whether TRO modifies thermal sensitivity in uterine cervical cancer cells, which is most commonly treated by hyperthermia (HT). MATERIALS AND METHODS: HeLa cells were treated with 5microM TRO for 24 hours before HT at 42degrees C for 1 hour. Cell survival was analyzed by clonogenic assay. The expression of HSPs was analyzed by Western blot. SOD and catalase activity was measured and reactive oxygen species (ROS) was measured using 2',7'-dichlorofluorescin diacetate and dihydroethidium. RESULTS: The decreased cell survival by HT was increased by preincubation with TRO before HT. Expression of HSP 70 was increased by HT however, it was not decreased by preincubation with TRO before HT. The decreased Bcl-2 expression by HT was increased by preincubation with TRO. SOD and catalase activity was increased by 1.2 and 1.3 times,respectively with TRO. Increased ROS by HT was decreased by preincubation with TRO. CONCLUSION: TRO decreases thermal sensitivity through increased SOD and catalase activity, as well as scavenging ROS in HeLa cells.
Blotting, Western ; Catalase ; Cell Survival ; Cervix Uteri ; Chromans ; Ethidium ; Female ; Fever ; Fluoresceins ; Heat-Shock Proteins ; HeLa Cells ; Humans ; Reactive Oxygen Species ; Superoxide Dismutase ; Thiazolidinediones ; Uterine Cervical Neoplasms

OBJECTIVETo investigate the effect of PPARgamma1 gene overexpression on caveolin-1 mRNA and protein expressions in a murine macrophage cell line Raw264.7.

METHODSReplication-deficient recombinant adenovirus expression vector of PPARgamma1 was constructed using the AdEasy system. Raw264.7 cells were randomly treated as follows: P group (PPARgamma1 gene overexpression), T group (Troglitazone 40 micromol/L in DMSO), PT group (PPARgamma1 gene overexpression and Troglitazone) and control group. Changes of PPARgamma1 and caveolin-1 at mRNA and protein levels were investigated.

RESULTSCaveolin-1 expression can be detected by RT-PCR in Raw264.7, by immunocytochemistry method in cell and nuclear membrane but not by immunoblotting at protein level. Caveolin-1 expression at mRNA and protein levels in Raw264.7 were significantly higher in P, T and PT groups compared to control group and the expression was also significantly higher in PT group than that in P group and T group (P < 0.05). PPARgamma expression was significantly increased in PT group and P group where remained unchanged in T group compared to control group.

CONCLUSIONPPARgamma1 overexpression can upregulate caveolin-1 expression in macrophages. Troglitazone upregulated caveolin-1 expression in the absence of increased PPARgamma1 expressions at mRNA and protein levels.

Adenoviridae ; genetics ; Animals ; Caveolin 1 ; metabolism ; Cell Line ; Chromans ; pharmacology ; Gene Expression ; Macrophages ; drug effects ; metabolism ; Mice ; PPAR gamma ; genetics ; RNA, Messenger ; metabolism ; Thiazolidinediones ; pharmacology

PURPOSE: Sodium-4-phenylbutyrate (Na-4-PB) is an analogue of phenylacetate, which is a well-known redifferentiating agent. In vitro and in vivo studies on this agent have been done and the clinical relevance of Na-4-PB has been studied in other malignancies, but not in thyroid cancer. We investigated the effect of Na-4-PB on cell proliferation and differentiation in thyroid cancer cell lines. METHODS: We used 5 thyroid cancer cell lines: TPC-1, FTC-133, FTC-236, FTC-238 and XTC-1. MTT assay and flowcytometry were used to measure the agent's antiproliferative effects and the cell cycle change. We evaluated the PPARgamma expression via western blotting and the mRNA expressions of NIS, Tg and CD 97 were determined by performing RT-PCR. Troglitazone, a potent PPARgamma agonist, was used in combined treatment with Na-4-PB. RESULTS: Na-4-PB inhibited cell proliferation in a dose and time dependent manner in all 5 thyroid cancer cell lines. By performing flowcytometry in the FTC-133 and TPC-1 cell lines, we identified that the antiproliferative effect of Na-4-PB was associated with an increased apoptotic cell population. Treatment with Na-4-PB upregulated the PPARgamma expression, but the combined treatment of Na-4-PB with troglitazone did not seem to be synergistic for the antiproliferative effect. Treatment with Na-4-PB downregulated the CD97 mRNA expression and it upregulated the NIS and Tg mRNA expressions in both the FTC-133 and TPC-1 cell lines. CONCLUSION: Na-4-PB inhibited thyroid cancer cell proliferation by inducing apoptosis in a dose dependent manner. Treatment with Na-4-PB increased the expression of PPARgamma and it upregulated such differentiation markers as NIS and Tg, and it downregulated CD97, a dedifferentiation marker. Na-4-PB should be further evaluated as a new potential therapeutic agent for patients with thyroid cancer.
Antigens, Differentiation ; Apoptosis ; Blotting, Western ; Cell Cycle ; Cell Line ; Cell Proliferation ; Chromans ; Histone Deacetylase Inhibitors ; Humans ; Phenylacetates ; PPAR gamma ; RNA, Messenger ; Thiazolidinediones ; Thyroid Gland ; Thyroid Neoplasms

PURPOSE: We investigated the effects of phosphatase and tensin homologue deleted on chromosome 10 gene phosphatase and tensin homologue deleted on chromosome 10 gene (PTEN) expression on the cell proliferation and on the responsiveness of troglitazone in osteosarcoma cells. MATERIALS AND METHODS: Western blotting alnalysis was performed to detect the expression of PTEN in U-2OS cells treated with troglitazone. WST (water-soluble tetrazolium) assay was used to evaluate cell proliferation. Flow cytometry was used to determine cell apoptosis. Further, transfection of wild-type PTEN plasmid DNA was used to upregulate PTEN expression. RESULTS: Troglitazone treatment induced growth inhibition of U2-OS cells in a dose- and time-dependent manner. Troglitazone increased the expression of PTEN in a dose-dependent manner. PTEN upregulation induced by troglitazone treatment resulted in cell growth inhibition and apoptosis in U-2OS cells. PTEN over-expression by plasmid transfection enhanced these effects of troglitazone. Moreover, no changes were observed in the mutant type-PTEN group. CONCLUSION: Upregulation of PTEN is involved in the inhibition of cell growth and induction of cell apoptosis by troglitazone. Further, PTEN over-expression can cause cell growth inhibition in osteosarcoma cells and these cell growth inhibitions could be enhance by troglitazone treatment.
Apoptosis ; Blotting, Western ; Cell Proliferation ; Chromans ; Chromosomes, Human, Pair 10 ; DNA ; Flow Cytometry ; Humans ; Microfilament Proteins ; Osteosarcoma ; Plasmids ; Thiazolidinediones ; Transfection ; Up-Regulation

PURPOSE: Troglitazone (TRO) is a peroxisome proliferator-activated receptor gamma (PPARgamma) agonist. TRO has antiproliferative activity on many kinds of cancer cells via G1 arrest. TRO also increases Cu2+/Zn2+-superoxide dismutase (CuZnSOD) and catalase. Cell cycle, and SOD and catalase may affect on radiation sensitivity. We investigated the effect of TRO on radiation sensitivity in cancer cells in vitro. MATERIALS AND METHODS: Three human cervix cancer cell lines (HeLa, Me180, and SiHa) were used. The protein expressions of SOD and catalase, and catalase activities were measured at 2-10 microM of TRO for 24 hours. Cell cycle was evaluated with flow cytometry. Reactive oxygen species (ROS) was measured using 2',7'-dichlorofluorescin diacetate. Cell survival by radiation was measured with clonogenic assay. RESULTS: By 5 microM TRO for 24 hours, the mRNA, protein expression and activity of catalase were increased in all three cell lines. G0-G1 phase cells were increased in HeLa and Me180 by 5 microM TRO for 24 hours, but those were not increased in SiHa. By pretreatment with 5 microM TRO radiation sensitivity was increased in HeLa and Me180, but it was decreased in SiHa. In Me180, with 2 microM TRO which increased catalase but not increased G0-G1 cells, radiosensitization was not observed. ROS produced by radiation was decreased with TRO. CONCLUSION: TRO increases radiation sensitivity through G0-G1 arrest or decreases radiation sensitivity through catalase-mediated ROS scavenging according to TRO dose or cell types. The change of radiation sensitivity by combined with TRO is not dependent on the PPARgamma expression level.
Catalase ; Cell Cycle ; Cell Line ; Cell Survival ; Cervix Uteri ; Chromans ; Female ; Flow Cytometry ; Fluoresceins ; Humans ; PPAR gamma ; Radiation Tolerance ; Reactive Oxygen Species ; RNA, Messenger ; Thiazolidinediones ; Uterine Cervical Neoplasms

We investigated the effects of a hot-water extract of Artemisia iwayomogi, a plant belonging to family Compositae, on cardiac ventricular delayed rectifier K+ current (I(K)) using the patch clamp technique. The carbohydrate fraction AIP1 dose-dependently increased the heart rate with an apparent EC(50) value of 56.1+/-5.5 microgram/ml. Application of AIP1 reduced the action potential duration (APD) in concentration-dependent fashion by activating I(K) without significantly altering the resting membrane potential (IC(50) value of APD(50): 54.80+/-2.24, IC(50) value of APD(90): 57.45+/-3.47 microgram/ml). Based on the results, all experiments were performed with 50 microgram/ml of AIP1. Pre-treatment with the rapidly activating delayed rectifier K+ current (I(Kr)) inhibitor, E-4031 prolonged APD. However, additional application of AIP1 did not reduce APD. The inhibition of slowly activating delayed rectifier K+ current (I(Ks)) by chromanol 293B did not change the effect of AIP1. AIP1 did not significantly affect coronary arterial tone or ion channels, even at the highest concentration of AIP1. In summary, AIP1 reduces APD by activating I(Kr) but not I(Ks). These results suggest that the natural product AIP1 may provide an adjunctive therapy of long QT syndrome.
Action Potentials ; Artemisia ; Asteraceae ; Chromans ; Diphosphonates ; Heart Rate ; Humans ; Ion Channels ; Long QT Syndrome ; Membrane Potentials ; Muscle Cells ; Piperidines ; Plants ; Pyridines ; Sulfonamides

Inflammatory processes of vascular endothelial cells play a key role in the development ofatherosclerosis. We determined the anti-inflammatory effects and mechanisms of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on LPS-treated human umbilical vein endothelial cells (HUVECs) to evaluate their cardioprotective potential. Cells were pretreated with DHA, EPA, or troglitazone prior to activation with LPS. Expression of COX-2, prostaglandin E2 (PGE2) and IL-6 production, and NF-kappaB activity were measured by Western blot, ELISA, and luciferase activity, respectively. Results showed that EPA, DHA, or troglitazone significantly reduced COX-2 expression, NF-kappaB luciferase activity, and PGE2 and IL-6 production in a dose-dependent fashion. Interestingly, low doses (10 micrometer) of DHA and EPA, but not troglitozone, significantly increased the activity of NF-kappaB in resting HUVECs. Our study suggests that while DHA, EPA, and troglitazone may be protective on HUVECs under inflammatory conditions in a dose-dependent manner. However there may be some negative effects when the concentrations are abnormally low, even in normal endothelium.
Blotting, Western ; Chromans ; Cyclooxygenase 2 ; Dinoprostone ; Eicosapentaenoic Acid ; Endothelial Cells ; Endothelium ; Enzyme-Linked Immunosorbent Assay ; Human Umbilical Vein Endothelial Cells ; Humans ; Interleukin-6 ; Luciferases ; NF-kappa B ; Thiazolidinediones