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Journal Article 2011; 32(Suppl 1): 101-116 PubMed PMID: 22167207 Citation  Keywords:  Animals, Antineoplastic Combined Chemotherapy Protocols:pharmacology, Brain Neoplasms:drug therapy, DNA Damage, Dose-Response Relationship, Drug, Drug Evaluation, Preclinical, Ellipticines:administration & dosage, Histone Deacetylase Inhibitors:administra.   

OBJECTIVES: Valproic acid (VPA) and trichostatin A (TSA) exert antitumor activity as histone deacetylase inhibitors, whereas ellipticine action is based mainly on DNA intercalation, inhibition of topoisomerase II and formation of cytochrome P450 (CYP)- and peroxidase-mediated covalent DNA adducts. This is the first report on the molecular mechanism of combined treatment of human neuroblastoma UKF-NB-3 and UKF-NB-4 cells with these compounds.

METHODS: HPLC with UV detection was employed for the separation and characterization of ellipticine metabolites formed by microsomes and peroxidases. Covalent DNA modifications by ellipticine in neuroblastoma cells and in incubations with microsomes and peroxidases were detected by 32P-postlabeling. Expression of CYP enzymes, peroxidases and cytochrome b5 was examined by Western blot.

RESULTS: The cytotoxicity of ellipticine to neuroblastomas was increased by pre-treating these cells with VPA or TSA. A higher sensitivity of cells to ellipticine correlated with an increase in formation of covalent ellipticine-derived DNA adducts in these cells. To evaluate the mechanisms of this finding, we investigated the modulation by VPA and TSA of CYP- and peroxidase-mediated ellipticine-derived DNA adduct formation in vitro. The effects of ellipticine in the presence of VPA and TSA on expression of CYPs and peroxidases relevant for ellipticine activation and levels of cytochrome b5 and P-glycoprotein in neuroblastoma cells were also investigated. Based on these studies, we attribute most of the enhancing effects of VPA and TSA on ellipticine cytotoxicity to enhanced ellipticine-DNA adduct formation caused by an increase in levels of cytochrome b5, CYP3A4 and CYP1A1 in neuroblastoma cells. A lower sensitivity of UKF-NB-4 cells to combined effects of ellipticine with VPA and TSA than of UKF-NB-3 cells is also attributable to high levels of P-glycoprotein expressed in this cell line.

CONCLUSION: The results found here warrant further studies and may help in the design of new protocols geared to the treatment of high risk neuroblastomas....

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Journal Article 2010; 31(1): 87-91 PubMed PMID: 20150870 Citation  Keywords:  Animals, Antidiuretic Agents:administration & dosage, Ascorbic Acid:administration & dosage, Central Nervous System:drug effects, Consciousness, Dose-Response Relationship, Drug, Drug Evaluation, Preclinical, Injections, Intraventricular, Male, Natriuresi.   

OBJECTIVE: Ascorbic acid represents one of the most important antioxidants and neuromodulators, and plays an important role in the cerebral system. In the present study, we investigated the central effect of ascorbic acid on fluid regulation and electrolyte homeostasis.

METHODS: Male Wistar rats were implanted with stainless steel cannulas into the lateral ventricle, and sodiun excretion and urinary volume were measured after intracerebroventricular (i.c.v.) injection of ascorbic acid (200 or 600 nmol/rat). In another set of experiments, vasopressin and oxytocin plasma levels were evaluated 10, 20 and 30 minutes after ascorbic acid i.c.v. injection.

RESULTS: The administration of ascorbic acid to conscious rats resulted in a significant decrease in urinary volume and an increase in the renal excretion of sodium, with a concomitant increase in the plasma levels of vasopressin and oxytocin.

CONCLUSIONS: These results suggest that ascorbic acid may play a significant role in the central regulation of fluid and electrolyte homeostasis....

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Journal Article 2010; 31(1): 137-146 PubMed PMID: 20150865 Citation  Keywords:  Acetylcysteine:pharmacology, Ambroxol:pharmacology, Animals, Antioxidants:pharmacology, Antithyroid Agents:administration & dosage, Drug Evaluation, Preclinical, Free Radical Scavengers:pharmacology, Injections, Intraperitoneal, Lipid Peroxidation:drug ef.   

OBJECTIVE: A possible role of antioxidants in thyreotoxicosis was investigated. We examined the parameters of lipid peroxidation (LPO): conjugated dienes (CD), malondialdehyde (MDA), Schiff bases (SB) in lung homogenates of male Wistar rats.

METHODS: Two control groups were created: Group 1 - intact animals and Group 2 - animals injected with 0,9% NaCl. In Experiment I, the animals received L-thyroxin (LT4) i.p. (Groups 3-7). After one week the rats received additionally: Group 4 - melatonin (MEL); Group 5 - propylthiouracil (PTU); Group 6 - Ambroxol (AMB); Group 7 - N-acetylocysteine (NAC). In Experiment II, the animals received only antioxidants.

RESULTS: In Experiment I, we noticed a significantly higher MDA and SB level in Group 2, compared to that in Group 1. Moreover, we observed a significantly higher MDA and SB level in Group 3, vs. that in Group 1, but SB level was lower in Group 3 than in Group 2. Melatonin, PTU and NAC reduced CD; PTU, AMB diminished MDA and MEL, AMB lowered SB levels as compared to Group 3. In Experiment II, we observed significantly higher MDA and SB level in Group 2, vs. that in Group 1. Melatonin, AMB and NAC decreased MDA and SB level, when compared to Group 2 but PTU elevated MDA and SB level vs. that in Group 1.

CONCLUSIONS: 1) L-T4 suppresses LPO, 2) MEL, AMB and NAC protect against LPO, 3) PTU is an antioxidant in thyreotoxicosis, however, when administered alone, it enhances LPO, 4) stress accelerate LPO....

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Journal Article 2009; 30(1): 144-152 PubMed PMID: 19300402 Citation  Keywords:  Animals, Bradykinin:administration & dosage, Bradykinin Receptor Antagonists, Diabetes Mellitus, Experimental:chemically induced, Diabetic Neuropathies:chemically induced, Drug Evaluation, Preclinical, Enzyme Inhibitors:administration & dosage, Hyperalges.   

PURPOSE: The influence of an irreversible inhibitor of constitutive NO synthase (L-NOArg; 1.0 mg/kg ip), a relatively selective inhibitor of inducible NO synthase (L-NIL; 1.0 mg/kg ip) and a relatively specific inhibitor of neuronal NO synthase (7-NI; 0.1 mg/kg ip), on antihyperalgesic action of selective antagonists of B2 and B1 receptors: D-Arg-[Hyp3,Thi5,D-Tic7,Oic8] bradykinin (HOE 140; 70 nmol/kg ip) or des Arg10 HOE 140 (70 nmol/kg ip) respectively, in model of diabetic (streptozotocin-induced) and toxic (vincristine-induced) neuropathy was investigated.

METHODS: The changes in pain thresholds were determined using mechanical stimuli--the modification of the classic paw withdrawal test described by Randall-Selitto.

RESULTS: The results of this paper confirm that inhibition of bradykinin receptors and inducible NO synthase but not neuronal NO synthase activity reduces diabetic hyperalgesia. Pretreatment with L-NOArg and L-NIL but not 7-NI, significantly increases antihyperalgesic activity both HOE 140 and des Arg10 HOE 140. It was also shown that both products of inducible NO synthase and neuronal NO synthase activation as well as bradykinin are involved in hyperalgesia produced by vincristine. Moreover, L-NOArg and 7-NI but not L-NIL intensify antihyperalgesic activity of HOE 140 or des-Arg10HOE 140 in toxic neuropathy.

CONCLUSIONS: Results of these studies suggest that B1 and B2 receptors are engaged in transmission of nociceptive stimuli in both diabetic and toxic neuropathy. In streptozotocin-induced hyperalgesia, inducible NO synthase participates in pronociceptive activity of bradykinin, whereas in vincristine-induced hyperalgesia bradykinin seemed to activate neuronal NO synthase pathway. Therefore, concomitant administration of small doses of bradykinin receptor antagonists and NO synthase inhibitors can be effective in alleviation of neuropathic pain, even in hospital care....

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Journal Article 2009; 30(1): 107-110 PubMed PMID: 19300395 Citation  Keywords:  Acromegaly:etiology, Adenoma:complications, Adrenocorticotropic Hormone:secretion, Adult, Aged, Cell Proliferation:drug effects, Cell Survival:drug effects, Drug Evaluation, Preclinical, Female, Human Growth Hormone:secretion, Humans, Hypoglycemic Agents:.   

OBJECTIVES: Rosiglitazone (RGZ) belongs to thiazolidinediones - new class of antidiabetic drugs which are PPARgamma agonists. It was shown that tumoral tissue, including the pituitary adenomas, posses PPARgamma receptors. The activation of PPARgamma receptors inhibits tumour growth in rodents and induces the oncostatic effect on human cancer cell lines. The aim of the present study was to examine the anti-tumour effect of RGZ on human pituitary adenomas in vitro.

MATERIALS AND METHODS: Cells of eight pituitary adenomas removed neurosurgically were used to our experiment. Before the operation, the hormonal secretion of the tumour was estimated. After the surgery, the histological diagnosis and immunohistochemical detection of pituitary hormones and PPARgamma receptors were performed. The cells of pituitary tumours were exposed in the primary culture to RGZ at the concentrations of 10(-9)-10(-4) M for 24 hours. To measure the cell growth the modified colorimetric Mossman method detecting the cells viability was applied.

RESULTS: On the basis of the pre-operative diagnosis the 6 clinically non-functioning adenomas (CNFPA), one case of acromegaly and one case of Cushing's disease were recognized. In 5 out of 6 CNFPA the immunopositive reaction for different pituitary hormones such as: LH, HGH, PRL, FSH and alpha-subunit was detected. Expression of PPARgamma was found in all examined tumours. Rosiglitazone decreased the cell viability of all CNFPA and corticotropinoma for 20% or more. In somatotropinoma inhibition of the cell growth was about 13%. There is no correlation between PPARgamma expression and efficacy of rosiglitazone. THE MAIN FINDING: The obtained results indicate that RZG exerts a suppressive effect on the cell viability in non-functioning pituitary adenomas. The lack of correlation between PPARgamma expression and anti-tumoral effect of RZG suggests that the above-mentioned action of this compound is independent on PPARgamma expression.

CONCLUSION: Our data suggest that rosiglitazone may be useful in the treatment of non-functioning pituitary adenomas, but its efficacy in Cushing's disease and acromegaly requires further study....

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Journal Article 2009; 30(1): 131-138 PubMed PMID: 19300393 Citation  Keywords:  Adult, Blood Cells:drug effects, Catechin:pharmacology, Cell Culture Techniques, Cell Nucleus:drug effects, Cell Proliferation:drug effects, Cells, Cultured, Drug Evaluation, Preclinical, Female, Humans, Interleukin-10:blood, Interleukin-6:blood, Interleu.   

OBJECTIVES: Cytokines induce the balance between inflammatory versus regulatory or antibody mediated reactions. So modulating the release of cytokines or inducing them by immunomodulating agents is an attractive mode for treating or help in treating several diseases such as autoimmune diseases. Eriobotrya japonica is a plant that is traditionally thought to have anti-inflammatory activities. Several compounds were isolated from the plant and showed distinctive biological effects. The purpose of this study was to determine the effects of epicatechin (EC) isolated from Eriobotrya Japonica on IL-6, IL-8, and IL-10 productions in whole blood stimulated with phytohemagglutinin (PHA)+lipopolysaccharide (LPS), and to examine if these cytokines are modulated through NFkappaB pathway.

METHODS: Sixteen healthy males and females volunteered in the study. Blood samples were drawn, diluted, and cultured for 24 h with different concentrations of EC and then PHA+LPS was added for another 24 h. The supernatant, then, was harvested and assayed for cytokines. In addition, mixing studies of EC and hydrocortisone were performed to examine the cytoplasmic and nuclear fractions of NFkB levels in association with cytokine production levels.

RESULTS: Increasing concentrations of EC (1-100 microg/ml) in PHA+LPS stimulated whole blood cells culture suppressed significantly (p<0.001) the production of IL-6 and IL-8. Moreover, increasing concentrations of EC modulated significantly the production of IL-10, as there was a significant increase in IL-10 level at 0.1, 1.0, and 10 microg/ml (p=0.058-0.004), while a significant decrease at a concentration of 100 microg/ml EC (p=0.037) was observed. In addition, an additive effect between EC and hydrocortisone (HC, 100 nmol/l) was seen in the production of IL-10, as there was a significant increase in IL-10 level (32%) compared with 27% for EC (10 microg/ml) and 19% HC. Furthermore, a significant decrease in cytoplasmic fractions of NFkappaB p65 level was found in samples containing EC 1, 10 microg/ml, but not in 100 microg/ml, when compared with control (p<0.03). These latter changes were accompanied with a 29%, 67%, and 98% increase, respectively, of NFkappaB p65 in nuclear fractions compared to 24% reduction of NFkappaB p65 level in HC culture (p<0.03).

CONCLUSIONS: These results indicate that EC suppresses the production of pro-inflammatory cytokines, IL6 and IL-8, enhances the production of anti-inflammatory cytokine, IL-10, and stimulates NFkappaB p65 translocation to nucleus in PHA+LPS stimulated whole blood culture....

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Comparative Study 2007; 28(2): 170-174 PubMed PMID: 17435667 Citation  Keywords:  Animals, Brain Ischemia:drug therapy, Drug Evaluation, Preclinical, Erythropoietin:administration & dosage, Infarction, Middle Cerebral Artery:drug therapy, Injections, Intraperitoneal, Male, Neuroprotective Agents:administration & dosage, Rats, Rats, Spr.   

OBJECTIVE: Majority of severe disabilities in adults are caused by stroke. The aim of our study is to learn the effects of erythropoietin (EPO), on infarct size in cerebral ischemia and to determine neurological behavioral scores and histopathological evaluation.

MATERIAL & METHODS: In this study 30 adult Sprague-Dawney rats were used. Cerebral ischemia was constituted by intraluminal filament method with a 4-0-nylon suture. Reperfusion was started after two hours of middle cerebral artery occlusion. The rats were randomly divided into two groups as follow: control and EPO groups. Saline 0.9% (0.5 ml/kg) and EPO (5 000 U/kg) was administered intraperitoneally in the groups. Three coronal slices in two millimeters thickness were obtained from cerebrum, cerebellum and brain stem, and were stained with a 2% solution of triphenyltetrazolium chloride. Transparent sheets were placed over each section and the areas of the brain and infarct were measured. The neurological scores were determined at 24th, 48th and 72nd hours after reperfusion.

RESULTS: Percent of ischemic area (%) in cerebrum, cerebellum and brain stem level in EPO groups were less than those of control group (p<0.0001). In addition, we determined that EPO group was better than controls of neurologic score and histopathologically after cerebral ischemia.

CONCLUSIONS: We concluded that EPO may decrease ischemic area in experimental cerebral ischemia in rats and it seems that EPO may be beneficial....

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Journal Article 2007; 28(2): 204-212 PubMed PMID: 17435663 Citation  Keywords:  Animals, Cell Line, Tumor, Cell Survival:drug effects, Curcumin:pharmacology, DNA, Neoplasm:analysis, Dose-Response Relationship, Drug, Drug Evaluation, Preclinical, Gap Junctions:chemistry, Glycoproteins:analysis, Metalloproteases:analysis, Mice, Neurobl.   

OBJECTIVE: Neuroblastoma (NB) is a well-known malignant disease in infants, which comprises 10% of childhood malignancies. Despite recent advances in understanding the neuro-oncology, NB still accounts for more death in childhood than any other cancer. Research in childhood tumors should not only be focused on the malignant signatures of cancer cells but also novel drug prototypes using phytochemicals. The present study was aimed to determine the role of curcumin against murine neuroblastoma cell line (N2a).

METHODS: The in vitro assessment of curcumin against was made in N2a cell line in a dose-dependent manner (group I (control) and group II - IX (10 microM-80 microM). The efficacy of the drug was evaluated by estimating the levels of protein bound carbohydrates, glycoprotein, genomic DNA, total RNA levels, and inhibition of MMP-9 were studied. The gap junctional communication in the cells was also assessed.

RESULTS: The levels of protein bound carbohydrates, DNA, RNA levels, glycoprotein were found to be altered on drug supplementation in NB cells. Inhibition of MMP-9 in curcumin-supplemented N2a cells was revealed by zymographic analysis. Assessment of Lucifer yellow dye uptake in curcumin-supplemented N2a cells showed the up-regulation of GJIC.

CONCLUSIONS: These observations suggest that the curcumin, the active principle of curcuma longa, could be developed into an effective chemo preventive and chemotherapeutic agent. This selected concentration range needs further studies at molecular level, for conforming its role and its action against uncontrolled proliferation of NB....

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