Wednesday, February 13, 2008

Comparative effects of the alpha7 nicotinic partial agonist, S 24795, and the cholinesterase inhibitor, donepezil, against aging-related deficits in d

Centre Neurosciences Intégratives et Cognitives, Université Bordeaux 1; CNRS 5228, Avenue des facultés, Talence, 33405, France, a.marighetto@cnic.u-bordeaux1.fr.
INTRODUCTION: The comparative effects of a newly described specific alpha7 nAChR partial agonist, S 24795, and a cholinesterase inhibitor, donepezil, currently used as a symptomatic Alzheimer's disease treatment were studied in two mouse models of aging-related memory deficits. MATERIALS AND METHODS: We employed radial arm-maze paradigms assessing short-term working memory (STWM, experiment A) and mnemonic flexibility, a cardinal property of long-term declarative (LTDM, experiment B). Both compounds were administered daily at 0.3 and 1 mg/kg subcutaneously ( approximately 3 weeks). RESULTS: In the STWM experiment, vehicle-treated aged mice displayed a severe and persistent deficit in the retention of successive arm visits in comparison to younger controls. S 24795 at 1 mg/kg (trends at 0.3 mg/kg) and donepezil at 0.3 mg/kg (but not 1 mg/kg) exerted beneficial effects on this deficit: The performance of aged mice treated with these drugs remarkably increased across the testing days and almost reached young adult performance level. In the critical test trials of memory flexibility (i.e., LTDM), in experiment B, S 24795 at 1 mg/kg (trends at 0.3 mg/kg) and donepezil at the dose of 1 mg/kg (but not 0.3 mg/kg) improved aged mice performance. CONCLUSION: This preclinical demonstration that S 24795 restored specific age-related memory deficits with as much efficacy as donepezil adds to recent literature in highlighting the potential interest of an alpha7 nAChR drug as a symptomatic AD therapeutic.
PMID: 18265960 [PubMed - as supplied by publisher]

Stereochemical study of tolperisone, a muscle relaxant agent, by circular dichroism and ultraviolet spectroscopy.

Department of Molecular Pharmacology, Institute of Chemistry, Budapest, Hungary. ZSFERI@CRIC.CHEMRES.HU
The stereochemistry of tolperisone, a chiral aryl-alkyl basic ketone was investigated by means of circular dichroism (CD) and ultraviolet (UV) spectroscopy. The unusually high optical activity of tolperisone hydrochloride in the n-->pi* region is interpreted by the presence of a chiral conformer in solution. For stereochemical reasons, the C = O group and the aromatic moiety lack coplanarity by forming an inherently dissymetric chromophore, of M helicity. Similar helicity prevails in the crystal phase, according to the solid-state CD spectrum of (-)-tolperisone HCl salt. The chirality rule proposed by Snatzke for nonplanar benzoyl chromophores predicts the absolute configuration of (-)-tolperisone hydrochloride to be R, in agreement with other alpha-methyl-beta-amino-ketones. Copyright 2000 Wiley-Liss, Inc.
PMID: 11054830 [PubMed - indexed for MEDLINE]

Influence of Lansoprazole and Rabeprazole on Mycophenolic Acid Pharmacokinetics One Year After Renal Transplantation

Peptic ulcer disease is a common complication after organ transplantation, and long-term administration of antiulcer agents is needed in many renal transplant recipients. Although several drug interactions with mycophenolic acid (MPA), the active metabolite of the prodrug mycophenolate mofetil (MMF), have been reported, little is known about the interaction between MPA and proton pump inhibitors (PPIs). The present study investigated the drug interaction between MMF and lansoprazole or rabeprazole and the impact of cytochrome (CYP) 2C19, and multidrug resistance (MDR)1 C3435T polymorphisms on these drug interactions at 1 year after renal transplantation. Retrospectively, 61 recipients were divided into 3 groups: MMF and tacrolimus as combination immunosuppressive therapy, together with either 30 mg lansoprazole (n = 22) or 10 mg rabeprazole (n = 17), or without PPI (n = 22). One year after transplantation, plasma concentrations of MPA were measured by high-performance liquid chromatography. The mean dose-unadjusted and -adjusted Cmax of MPA with 30 mg lansoprazole were significantly lower than those without PPI (11.8 vs. 17.8 mug/mL, P = 0.0197, and 22.6 vs. 33.1 ng/mL/mg MMF, P = 0.0222, respectively). In recipients having the CYP2C19 *1/*2+*1/*3 or MDR1 C3435T CC genotype, the mean dose-adjusted AUC0-12 of MPA with 30 mg lansoprazole was significantly smaller than that with 10 mg rabeprazole or without PPI. The plasma concentration of MPA was influenced by 30 mg lansoprazole but not 10 mg rabeprazole. Because of the greater gastric acid secretion-inhibitory effect of 30 mg lansoprazole in recipients having the CYP2C19 *1/*2+*1/*3 (intermediate metabolizer) or MDR1 C3435T CC genotype, the elution and hydrolysis of MMF might be decreased. Although the clinical relevance might be minor, the fact that administration of 30 mg lansoprazole in patients having the CYP2C19 *2 or *3 allele or the MDR1 C3435T CC genotype diminishes the absorption of MPA in the maintenance stage after renal transplantation should be taken into consideration with regard to the MPA pharmacokinetics.
PMID: 18223462 [PubMed - as supplied by publisher]

Chemotherapy for advanced, recurrent, and metastatic cervical cancer.

Gynecologic Oncology of Indiana, Indianapolis, Indiana; Correspondence: David H. Moore, MD, Gynecologic Oncology of Indiana, 5255 East Stop 11 Road, Suite 310, Indianapolis, IN 46237. E-mail: David.Moore@ssfhs.org.
When cervical cancer is beyond curative treatment with surgery or radiation therapy, the prognosis is poor and palliation is the primary objective. Early prospective studies identified cisplatin as an active drug for advanced, metastatic, or recurrent cervical cancer, and results with other platinum analogs seemed inferior to cisplatin. Several phase III trials have established the combination of cisplatin plus paclitaxel as standard therapy for comparison. Using pooled data from 3 Gynecologic Oncology Group (GOG) phase III studies, a predictive model was developed to better identify patients who are unlikely to respond to cisplatin-containing chemotherapy. The GOG is currently developing a phase III trial to investigate the impact of bevacizumab and a regimen containing topotecan instead of cisplatin in combination with paclitaxel chemotherapy and also to externally validate the predictive model. This study has the potential to radically change standard care for cervical cancer chemotherapy. Furthermore, if the predictive model is upheld, then patients with high risk factors for treatment failure may be directed to chemotherapy regimens that do not include cisplatin or to investigational trials.
PMID: 18267059 [PubMed - in process]

Attenuation of oxidative stress in plasma and tissues of rats with experimentally induced hyperthyroidism by caffeic acid phenylethyl ester.

Biochemistry Department and Tumor Marker Oncology Research Unit, Faculty of Pharmacy, Al-Azhar University, Cairo, Eygpt. amohamadin@yahoo.com
Increased oxidative stress with high free radical generation has been described previously in animal models of hyperthyroidism. The present study was designed to investigate the protective effects of caffeic acid phenylethyl ester (CAPE) on oxidative damage in rats with experimentally induced hyperthyroidism. The study was conducted on 32 male Sprague-Dawley rats. The experimental animals were divided into four groups (control, CAPE alone, hyperthyroidism, and hyperthyroidism + CAPE). Hyperthyroidism was induced by intraperitoneal administration of 0.3 mg/kg/day L-thyroxine for 4 weeks. CAPE (10 micro g/kg) was administered intraperitoneally for 4 weeks. At the end of the experimental period, blood samples and various organs (liver, heart and brain) of rats were taken for the determination of thiobarbituric acid reactive substances (TBARS), reduced glutathione (GSH), oxidized glutathione, vitamin C and superoxide dismutase (SOD) levels and concentrations of triiodothyronine (T3), thyroxine (T4) and thyroxine-stimulating hormone (TSH). Our results indicate that TBARS, oxidized glutathione, SOD levels and concentrations of T3 and T4 were higher in plasma and tissues of the hyperthyroid group compared to controls. Vitamin C, GSH and TSH levels were decreased significantly in the hyperthyroid group when compared to the control group. CAPE treatment decreased the elevated TBARS, SOD, T3 and T4 levels and increased the lowered GSH, vitamin C and TSH levels to control levels in rats with hyperthyroidism. In conclusion, our results indicate that CAPE is beneficial as a protective agent against oxidative stress induced by hyperthyroidism in rats. The protection is probably due to multiple mechanisms involving free radical scavenger properties, attenuating lipid peroxidation and increasing the antioxidant status.
PMID: 17244256 [PubMed - indexed for MEDLINE]

Wednesday, January 16, 2008