Home About us Contact
|
Home About us Contact | ||
|
|
||
Daily Oral Administration (daily + oral_administration)
Selected AbstractsHypolipidemic activity of Anethum graveolens in ratsPHYTOTHERAPY RESEARCH, Issue 3 2008Valiollah Hajhashemi Abstract The aerial parts of Anethum graveolens (dillweed) are used in Iran as a hypolipidemic agent. The scientific basis for its use has yet to be established. In this study the hypolipidemic activity of dill powder and its essential oil (its most important fraction) were evaluated in male Wistar rats (180 ± 20 g) fed a high cholesterol diet. Anethum graveolens essential oil (AGEO) was prepared by hydrodistillation and analysed using GC/MS. AGEO had a yield of 2% and GC/MS analysis showed that , -phellandrene (32%), limonene (28%) and carvone (28%) were its major components. Daily oral administration of AGEO to rats at doses of 45, 90 and 180 mg/kg for 2 weeks significantly and in a dose-dependent manner reduced total cholesterol, triglyceride and low density lipoprotein cholesterol (LDL-C). AGEO also increased significantly high density lipoprotein cholesterol (HDL-C). Anethum graveolens powder when added to the diet of animals showed similar effects on serum lipids. It is concluded that Anethum graveolens has significant lipid lowering effects and is a promising cardioprotective agent. Copyright © 2007 John Wiley & Sons, Ltd. [source] Chronic Prenatal Ethanol Exposure Increases Glucocorticoid-Induced Glutamate Release in the Hippocampus of the Near-Term Foetal Guinea PigJOURNAL OF NEUROENDOCRINOLOGY, Issue 11 2006U. Iqbal Exposure to high cortisol concentration can injure the developing brain, possibly via an excitotoxic mechanism involving glutamate (Glu). The present study tested the hypothesis that chronic prenatal ethanol exposure (CPEE) activates the foetal hypothalamic-pituitary-adrenal axis to produce high cortisol exposure in the foetal compartment and alters sensitivity to glucocorticoid-induced Glu release in the foetal hippocampus. Pregnant guinea pigs received daily oral administration of ethanol (4 g/kg maternal body weight/day) or isocaloric-sucrose/pair-feeding from gestational day (GD) 2 until GD 63 (term, approximately GD 68) at which time they were euthanised, 1 h after their final treatment. Adrenocorticotrophic hormone (ACTH) and cortisol concentrations were determined in foetal plasma. Basal and electrically stimulated Glu and ,-aminobutyric acid (GABA) efflux in the presence or absence of dexamethasone (DEX), a selective glucocorticoid-receptor agonist, were determined ex vivo in foetal hippocampal slices. Glucocorticoid receptor (GR), mineralocorticoid receptor (MR) and N -methyl- d -aspartate (NMDA) receptor NR1 subunit mRNA expression were determined in situ in the hippocampus and dentate gyrus. In the near-term foetus, CPEE increased foetal plasma ACTH and cortisol concentrations. Electrically stimulated glutamate, but not GABA, release was increased in CPEE foetal hippocampal slices. Low DEX concentration (0.3 µM) decreased stimulated glutamate, but not GABA, release in both CPEE and control foetal hippocampal slices. High DEX concentration (3.0 µM) increased basal release of Glu, but not GABA, in CPEE foetal hippocampal slices. GR, but not MR, mRNA expression was elevated in the hippocampus and dentate gyrus, whereas NR1 mRNA expression was increased in the CA1 and CA3 fields of the foetal hippocampus. These data demonstrate that CPEE increases high glucocorticoid concentration-induced Glu release in the foetal hippocampus, presumably as a consequence of increased GR expression. These effects of CPEE, coupled with increased glutamate release and increased NMDA receptor expression, may predispose the near-term foetal hippocampus to GR and Glu-NMDA receptor-mediated neurodevelopmental toxicity. [source] Effects of Long-Term Hormone Treatment and of Tibolone on Monoamines and Monoamine Metabolites in the Brains of Ovariectomised, Cynomologous MonkeysJOURNAL OF NEUROENDOCRINOLOGY, Issue 9 2006R. B. Gibbs The effects of long-term hormone treatment on monoamines and monoamine metabolites in different regions of the primate brain were examined and compared. Ovariectomised Cynomologous monkeys received daily oral administration of either conjugated equine oestrogens (CEE), CEE + medroxyprogesterone acetate (MPA), or a low or high dose of tibolone, for a period of 2 years. Tissue punches collected from frozen sections through various regions of the forebrain, midbrain, and hindbrain were assayed for levels of dopamine, dihydroxyphenylacetic acid (DOPAC), serotonin, 5-hydroxyindole acetic acid (5-HIAA), and norepinephrine by high-performance liquid chromatography. Few differences between hormone-treated animals and ovariectomised controls were observed. No statistically significant effects of CEE relative to controls were detected in any of the seven brain regions analysed. Animals treated with CEE + MPA showed significant reductions in 5-HIAA in the dorsal raphe nucleus, a significant reduction in dopamine in the hypothalamus, and a significant reduction in serotonin (5-HT) levels in area 8AD of the frontal cortex. Similar to CEE, no significant effects of tibolone relative to controls were detected; however, animals treated with high-dose tibolone showed a decrease in 5-HT levels in the frontal cortex that approached significance and was similar to the effect of CEE + MPA. Collectively, the findings suggest that long-term oral administration of these compounds has relatively few effects on the levels of dopamine, serotonin, and their primary metabolites in the primate brain. This differs from the significant effects on serotonergic and dopaminergic systems detected following parenteral treatment with oestradiol and progesterone, and likely reflects differences between the effects of treating with CEE + MPA versus oestradiol and progesterone on brain monoaminergic systems. [source] Effects of long-term oral administration of polymeric microcapsules containing tyrosinase on maintaining decreased systemic tyrosine levels in ratsJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 4 2004Binglan Yu Abstract There is no effective treatment for melanoma, a fatal skin cancer occurring with increasing frequency. Dietary tyrosine restriction lowers systemic tyrosine and suppresses the growth of melanoma in mice, but this is not tolerated by human resulting in nausea, vomiting, and weight loss. We report here the successful use of oral polymeric microcapsules containing tyrosinase to lower the systemic tyrosine level in the rats. We found that microencapsulated tyrosinase incubated with intestinal content of rats selectively lowered the tyrosine level. We then studied the daily oral administration of microencapsulated tyrosinase in rats of one dose a day, two doses a day, and three doses a day over a period of up to 22 days. With three doses a day, the tyrosine levels in the test group decreased to 68.8% of the control group by day 4 and then decreased to 52.6% after this and remained at this level throughout the 22 days test period. This is the level shown earlier by other workers using dietary restriction of tyrosine to result in suppression of growth of melanoma. However, unlike dietary tyrosine restriction, oral tyrosinase microcapsules did not result in adverse effects nor significant differences in growth (weight gain) when compared to the control group. This approach can also be used for the lowering of systemic tyrosine in hypertyrosinemia, an inborn error of metabolism. © 2004 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 93: 831,837, 2004 [source] Hypoglycaemic effect of Calamintha officinalis Moench. in normal and streptozotocin-induced diabetic ratsJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 6 2004A. Lemhadri The purpose of this study was to investigate the effects of a water extract from the aerial parts of Calamintha officinalis Moench., after either a single dose or daily oral administration for 15 days, on plasma blood glucose concentrations and basal insulin levels in normal and streptozotocin-induced diabetic rats (STZ diabetic rats). The results clearly demonstrated the hypoglycaemic effect of this plant extract in both normal and STZ diabetic rats. In addition, no changes were observed in basal plasma insulin concentrations after treatment with this plant in normal or STZ diabetic rats, indicating that the underlying mechanism of the plant's pharmacological action seems to be independent of insulin secretion. We conclude that the aqueous C. officinalis extract exhibits a significant hypoglycaemic effect in normal and STZ diabetic rats without affecting basal plasma insulin concentrations, and supports, therefore, its traditional use by the Moroccan population. [source] Decreased biliary excretion of tributylmethyl ammonium in cholestyramine pretreated rats due to reduced formation of ion-pair complexes with hepatic bile saltsBIOPHARMACEUTICS AND DRUG DISPOSITION, Issue 9 2007M. K. Choi Abstract The hypothesis that higher molecular weight (MW) quaternary ammoniums (QAs) form lipophilic ion-pair complexes with bile salts in the liver, and are subsequently excreted into bile via a canalicular transporter, P-gp, was re-examined in the present study for its validity. The biliary excretion of tributylmethyl ammonium (TBuMA), a QA with a MW of 200, in bile salt-depleted rats was determined. Depletion was induced by a daily oral administration of a resin, cholestyramine, at a dose of 0.5,g/kg for 2 consecutive weeks, which decreased the concentration of total bile salts in the liver by 38%. When TBuMA was administered intravenously (12,µmol/kg) to these rats, the plasma level, area under the plasma concentration-time curve (AUC), systemic clearance (CL) and volume of distribution (Vss) of the compound remained unchanged, whereas bile flow (23.03 vs 16.94,µl/min, p<0.05) and biliary clearance (CLbile, 12.75 vs 5.34,ml/min/kg, p<0.01) were decreased significantly. These results implied the biliary clearance of TBuMA in rats with bile salt depletion was significantly decreased as a result of decreased ion-pair complexation of TBuMA. The above results are consistent with our hypothesis and the existence of a MW threshold (i.e. 200±50 for rats) for the biliary excretion of QAs. Copyright © 2007 John Wiley & Sons, Ltd. [source] | ||||||||||