Effectiveness of Miltefosine Treatment in Targeting Anti-Leishmanial HO-1/Nrf-2-Mediated Oxidative Responses in Visceral Leishmaniasis Patients.

Effectiveness of miltefosine treatment in targeting anti-leishmanial HO-1/Nrf-2-mediated oxidative responses in visceral leishmaniasis patients.

J Antimicrob Chemother. 2013 May 31;
Das S, Pandey K, Rabidas VN, Mandal A, Das P

OBJECTIVES: Miltefosine, an alkylphosphocholine anti-cancer drug, exhibits direct activity against Leishmania donovani and also promotes anti-leishmanial host immunomodulatory functions. Nuclear factor-erythroid 2-related factor 2 (Nrf-2), a redox-sensitive transcription factor, regulates the host stress responses leading to effective microbial clearance by a positive effect on haem oxygenase-1 (HO-1) enzyme expression/activity. We aimed to investigate the role of miltefosine in regulating HO-1/Nrf-2-mediated oxidative responses in visceral leishmaniasis (VL) patients in vivo and in vitro. METHODS: Splenic aspirate and bone marrow aspirate cells of VL patients (n?=?23) were used in the study. RT-PCR of HO-1, Nrf-2 translocation analysis and HO-1 ELISA were used to investigate the HO-1/Nrf-2-mediated modulation of oxidative responses by miltefosine in vivo. Fluorometric measurement of reactive oxygen species (ROS) was performed, determination of glutathione peroxidase (GPx) activity was performed, and bilirubin and superoxide dismutase (SOD) levels were determined. The in vitro HO-1/Nrf-2-dependent anti-leishmanial effect of miltefosine was assessed by the use of specific inhibitors/inducers and subsequent microscopic measurement of parasite killing and Th1/Th2 cytokine regulation by ELISA. RESULTS: Increased levels of transcript and serum HO-1, Nrf-2 nuclear translocation, serum bilirubin, GPx and SOD activity in untreated VL patients were reversed after miltefosine chemotherapy. The effectiveness of miltefosine for positive induction of ROS via NADPH correlated with a decrease in HO-1/ERK/Nrf-2-dependent parasite load. Furthermore, HO-1 blockade by miltefosine led to suppression of interleukin-10 and transforming growth factor-?, but enhanced interleukin-12 and tumour necrosis factor-? production, in VL patients. CONCLUSIONS: The antioxidant promoting property of L. donovani is crucial for protection against the mounting redox threat in the host. Therefore, these findings provide direct evidence for targeting HO-1/Nrf-2 as an anti-leishmanial approach for chemotherapy in human VL. HubMed – drug


Amphotericin B Formulations: A Comparative Review of Efficacy and Toxicity.

Drugs. 2013 Jun 1;
Hamill RJ

Because of the increasing prevalence and changing microbiological spectrum of invasive fungal infections, some form of amphotericin B still provides the most reliable and broad spectrum therapeutic alternative. However, the use of amphotericin B deoxycholate is accompanied by dose-limited toxicities, most importantly, infusion-related reactions and nephrotoxicity. In an attempt to improve the therapeutic index of amphotericin B, three lipid-associated formulations were developed, including amphotericin B lipid complex (ABLC), liposomal amphotericin B (L-AmB), and amphotericin B colloidal dispersion (ABCD). The lipid composition of all three of these preparations differs considerably and contributes to substantially different pharmacokinetic parameters. ABLC is the largest of the lipid preparations. Because of its size, it is taken up rapidly by macrophages and becomes sequestered in tissues of the mononuclear phagocyte system such as the liver and spleen. Consequently, compared with the conventional formulation, it has lower circulating amphotericin B serum concentrations, reflected in a marked increase in volume of distribution and clearance. Lung levels are considerably higher than those achieved with other lipid-associated preparations. The recommended therapeutic dose of ABLC is 5 mg/kg/day. Because of its small size and negative charge, L-AmB avoids substantial recognition and uptake by the mononuclear phagocyte system. Therefore, a single dose of L-AmB results in a much higher peak plasma level (Cmax) than conventional amphotericin B deoxycholate and a much larger area under the concentration-time curve. Tissue concentrations in patients receiving L-AmB tend to be highest in the liver and spleen and much lower in kidneys and lung. Recommended therapeutic dosages are 3-6 mg/kg/day. After intravenous infusion, ABCD complexes remain largely intact and are rapidly removed from the circulation by cells of the macrophage phagocyte system. On a milligram-to-milligram basis, the Cmax achieved is lower than that attained by conventional amphotericin B, although the larger doses of ABCD that are administered produce an absolute level that is similar to amphotericin B. ABCD exhibits dose-limiting, infusion-related toxicities; consequently, the administered dosages should not exceed 3-4 mg/kg/day. The few comparative clinical trials that have been completed with the lipid-associated formulations have not demonstrated important clinical differences among these agents and amphotericin B for efficacy, although there are significant safety benefits of the lipid products. Furthermore, only one published trial has ever compared one lipid product against another for any indication. The results of these trials are particularly difficult to interpret because of major heterogeneities in study design, disease definitions, drug dosages, differences in clinical and microbiological endpoints as well as specific outcomes examined. Nevertheless, it is possible to derive some general conclusions given the available data. The most commonly studied syndrome has been empiric therapy for febrile neutropenic patients, where the lipid-associated preparations did not appear to provide a survival benefit over conventional amphotericin B deoxycholate, but did offer a significant advantage for the prevention of various breakthrough invasive fungal infections. For treatment of documented invasive fungal infections that usually involved hematological malignancy patients, no individual randomized trial has demonstrated a mortality benefit due to therapy with one of the lipid formulations. Results from meta-analyses have been contradictory, with one demonstrating a mortality benefit from all-cause mortality and one that did not demonstrate a mortality benefit. In the only published study to examine HIV-infected patients with disseminated histoplasmosis, clinical success and mortality were significantly better with L-AmB compared with amphotericin B deoxycholate; there were no differences in microbiological outcomes between treatment groups. The lipid-associated preparations were not significantly better than amphotericin B deoxycholate for treatment of AIDS-associated acute cryptococcal meningitis for either clinical or microbiological outcomes that were studied. In all of the trials that specifically examined renal toxicity, the lipid-associated formulations were significantly less nephrotoxic than amphotericin B deoxycholate. Infusion-related reactions occurred less frequently with L-AmB when compared with amphotericin B deoxycholate; however, ABCD had equivalent or more frequent infusion-related reactions than conventional amphotericin B, and this resulted in the cessation of at least one clinical trial. At the present time, this particular lipid formulation is no longer commercially available. For the treatment of most invasive fungal infections, an amphotericin B lipid formulation provides a safer alternative than conventional amphotericin B, with at least equivalent efficacy. As the cost of therapy with these agents continues to decline, these drugs will likely maintain their important role in the antifungal drug armamentarium because of their efficacy and improved safety profile. HubMed – drug


Mini-review on Glycolysis and Cancer.

J Cancer Educ. 2013 Jun 1;
Akram M

Glycolysis is a universal pathway in the living cells. The complete pathway of glycolysis was elucidated in 1940. This pathway is often referred to as Embden-Meyerhof pathway in honor of the two biochemists that made a major contribution to the knowledge of glycolysis. The objective of the study was to review the published literature on glycolysis and relation to cancer. The material for this review was taken mostly from up-to-date biochemistry textbooks and electronic journals. To collect publications, PubMed and the Cochrane database of systematic reviews were used. Some other relevant references were collected from personal database of papers on glycolysis and cancer. Several glycolytic inhibitors are currently in preclinical and clinical development. Inhibition of glycolysis in cancer cells is a novel strategy to overcome drug resistance associated with mitochondrial respiratory defect and hypoxia. This article is an important topic to be considered by cancer researchers and those who treat cancers. HubMed – drug


Reports of Sexual Disorders Related to Serotonin Reuptake Inhibitors in the French Pharmacovigilance Database: An Example of Underreporting.

Drug Saf. 2013 Jun 1;
Trenque T, Maura G, Herlem E, Vallet C, Sole E, Auriche P, Drame M

BACKGROUND: Depressive disorders and use of antidepressants are associated with adverse effects on sexual function. In pharmacoepidemiological studies, sexual disorders are reported by more than 50 % of patients taking serotonin reuptake inhibitors (SRIs). OBJECTIVE: The aim of this study was to determine the reporting rate of sexual disorders in association with SRIs, and to investigate the association between reported cases and the use of SRIs. METHODS: All cases of adverse drug reactions (ADRs) involving sexual disorders, spontaneously reported to the French Pharmacovigilance Database from 1 January 1985 to December 2009, were reviewed. Cases of sexual disorders in SRI users were described. We calculated the rate of reported sexual disorders as a percentage of the total ADRs reported for each drug. The association between reported cases and the use of SRIs was assessed using reporting odds ratios (ROR) with 95 % confidence intervals (CIs). RESULTS: A total of 11,863 ADRs in association with SRIs were collected, of which 98 (0.83 %) were spontaneous reports of sexual disorders. Subjects were, on average, 45.0 ± 10.6 years of age and mainly male. Sexual disorders were associated with the use of SRI antidepressants (ROR 4.47; 95 % CI 3.61-5.53), milnacipran (ROR 11.72; 95 % CI 5.79-23.72), fluvoxamine (ROR 6.91; 95 % CI 3.79-12.58), paroxetine (ROR 5.54; 95 % CI 3.92-7.83), venlafaxine (ROR 3.50; 95 % CI 1.93-6.36), fluoxetine (ROR 3.46; 95 % CI 2.26-5.29), citalopram (ROR 2.69; 95 % CI 1.28-5.67) and sertraline (ROR 2.49; 95 % CI 1.03-6.01). CONCLUSION: It is likely that there are instances of underreporting, particularly for ADRs that are embarrassing to talk about spontaneously. Despite the likely underreporting of this well-described adverse effect, this case/non-case study performed in a large national pharmacovigilance database confirms the existence of the risk of sexual disorders associated with SRIs, and is an example of the lack of sensitivity of spontaneous notification to measure ADRs. Minimization of antidepressant-induced sexual dysfunction could be an important factor to avoid unsuccessful treatment. Physicians should advise their patients on the possible sexual adverse effects. HubMed – drug