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

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

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

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) 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

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

To explore the role of D(1)-dopamine receptor in the modulation of basic respiratory rhythm, neonatal (0-3 d) Sprague-Dawley rats of either sex were used. The medulla oblongata slice was prepared and the surgical procedure was performed in the modified Kreb's solution (MKS) with continuous ventilating 95% O2 and 5% CO2 and ended in 3 min. A 600-700 mum single transverse slice containing the hypoglossal nerve roots and some parts of the ventral respiratory group was cut. The preparation was quickly transferred to a recording chamber and continuously perfused with oxygen-saturated MKS at a rate of 4-6 mL/min at 27-29 degrees C. Ten medulla oblongata slice preparations were randomly divided into two groups. In group I, the preparations were perfused with perfusion solution containing D(1)-dopamine receptor specific agonist cis-(+/-)-1-(Aminomethyl)-3,4-dihydro-3-phenyl-1H-2-Benzopyran-5,6-Diolhy-drochlo-ride (A68930, 5 mumol/L) for 10 min first; after washing out, the preparations were then perfused with perfusion solution containing D(1)-dopamine receptor specific antagonist R(+)-7-Chloro-8-hydroxy-3-methyl-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine hydrochloride (SCH-23390, 2 mumol/L) for 10 min. In group II, after perfusion with A68930 for 10 min, the preparations were perfused with additional A68930 + SCH-23390 for 10 min. Respiratory rhythmical discharge activity (RRDA) of the rootlets of hypoglossal nerve was recorded by suction electrodes. The results showed that A68930 shortened the respiratory cycle (RC) and expiratory time (TE) with an increase in the integral amplitude (IA). However, SCH-23390 significantly prolonged RC and TE, and decreased IA with a decrease in inspiratory time (TI). Moreover, the effect of A68930 on the respiratory rhythm was partially reversed by additional application of A68930 + SCH-23390. These results indicate that D(1)-dopamine receptor is possibly involved in the modulation of the RRDA in the isolated neonatal rat brainstem slice.
Animals ; Animals, Newborn ; Benzazepines ; pharmacology ; Biological Clocks ; Chromans ; pharmacology ; Female ; In Vitro Techniques ; Male ; Medulla Oblongata ; physiology ; Rats ; Rats, Sprague-Dawley ; Receptors, Dopamine ; physiology ; Respiration

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

OBJECTIVETo investigate the role of dopamine-1 receptor in the modulation of basic respiration rhythm.

METHODSNewborn SD rat (0-3 days, n=20) brain stem slices containing the medial region of the nucleus retrofacialis (mNRF) were prepared with the hypoglossal nerve roots retained. The respiratory rhythmical discharge activity (RRDA) of the hypoglossal nerve was recorded using suction electrodes on these preparations, and the effects of dopamine-1 receptor on RRDA were investigated by application of the specific agonist of dopamine-1 receptor A68930 at different concentrations (0, 1, 2, and 5 micromol/L) in the perfusion solution.

RESULTSThe respiratory cycles (RC) and the expiratory time (TE) decreased progressively with gradual increment of the integrated amplitude (IA) after A68930 administration, and their changes were the most conspicuous at 5 min after the administration. A68930 at the concentrations of 2 and 5 micromol/L resulted in the most obvious changes in RC, TE, and IA (P<0.05), but IA exhibited no significant variation at 1 min after perfusion with 2 micromol/L A68930 (P>0.05). RC and TE were gradually shortened after treatment with increasing concentrations of A68930, which also caused gradual increment of IA, and at the concentration of 5 micromol/L, RC, TE, and IA all showed the most obvious changes (P<0.01).

CONCLUSIONSDopamine-1 receptor plays a role in the modulation of RRDA in isolated neonatal rat brainstem slice. A68930 may increase the frequency of respiration by shortening TE and enhance the respiratory activity by increasing the amplitude of inspiratory discharge of the respiratory neurons.

Animals ; Animals, Newborn ; Cell Separation ; Chromans ; pharmacology ; Dopamine Agonists ; pharmacology ; In Vitro Techniques ; Medulla Oblongata ; cytology ; physiology ; Neurons ; cytology ; Rats ; Rats, Sprague-Dawley ; Receptors, Dopamine ; physiology ; Respiration ; drug effects