Synthesis and Investigation of Novel Spiro-isoxazolines as Anti-Cancer Agents.

A series of structurally diverse 4-bromo spiro-isoxazolines possessing a variety of aromatic and aliphatic substituents at the 3 position, were synthesized through a 1,3-dipolar cycloaddition followed by intramolecular cyclization of a pendant hydroxyl or carboxylic acid group. The biochemical antiproliferative activity was evaluated in vitro by using two breast cancer cell lines (MCF-7 and MDA-MB-231) and two prostate cancer cell lines (PC-3 and DU-145) using the MTT viability assay, and the IC50 values were obtained. Spiro-isoxazoline derivatives bearing a p-chloro or an o-dichloro aromatic substituent at the 3-position of the isoxazoline showed considerable antitumor activities in all four cell lines with IC50 value ranging from 43µM to 56µM.

Multi-platform metabonomics unravel amino acids as markers of HIV/combination antiretroviral therapy-induced oxidative stress.

Infection by the human immunodeficiency virus (HIV) elicits an immune response wherein neutrophils produce reactive oxygen species (ROS) to defend against pathogen invasion. Consequently, disproportionate levels of ROS in relation to antioxidants lead to oxidative stress (OS), which plays a key role in HIV disease progression and pathogenesis. There is a close relationship between oxidative stress status and HIV infection/progression, both separately and in the presence of combination antiretroviral therapy (cART). Biomarkers of oxidative stress present an additional means of monitoring HIV disease progression and/or management. Thus, the objective of this study was to apply untargeted nuclear magnetic resonance (NMR)-based metabonomics followed by targeted quantitative gas chromatography-mass spectrometry (GC/MS) analyses to identify predictors of oxidative stress in HIV infected individuals, with or without cART. Untargeted NMR-based metabonomics allowed a global profiling of metabolic perturbations in HIV-infected sera. The cohort consisted of 21 HIV-negative control subjects (HIV-) and 113 HIV-infected individuals, of which 100 were on cART. Significant differences in metabolic features corresponding to changes in glucose, lipids, phenylalanine, glutamic acid, aspartic acid and branched amino acids were observed, which point to oxidative stress and insulin resistance. To further confirm oxidative stress, targeted GC/MS-based metabonomics, performed in succession, allowed for a quantitative description of a total of 9 oxidative stress-related metabolites. Significant up-regulation of aspartic acid, phenylalanine and glutamic acid were observed in the HIV-infected cohorts as compared to controls. Tryptophan and tyrosine were down-regulated whereas cystine levels were increased in HIV-infected and untreated individuals as compared to both HIV treated and negative control subjects. Pathway analysis also revealed 11 metabolic pathways to be significantly altered by infection and/or treatment. These pathways included aminoacyl-tRNA biosynthesis, nitrogen metabolism and phenylalanine, tyrosine and tryptophan biosynthesis. This pilot study demonstrated the use of multiplatform metabonomic strategies to elucidate metabolic markers that would be essential in predicting HIV/cART-induced oxidative stress. This could aid and contribute in HIV treatment and management programmes.

HIV/HAART-associated oxidative stress is detectable by metabonomics.

Chronic human immunodeficiency virus (HIV) infection, separately and in combination with highly active antiretroviral therapy (HAART) is closely associated with oxidative stress (OS). Most studies demonstrating redox imbalances in HIV-infected individuals have done so using conventional biochemical methodologies. The limited simultaneous detection of multiple OS markers within one sample is a major drawback of these methodologies and can be addressed through the use of metabonomics. HIV-metabonomic studies utilizing biofluids from HAART cohorts as the investigative source, are on the increase. Data from many of these studies identified metabolic markers indicative of HIV-induced OS, usually as an outcome of an untargeted metabonomics study. Untargeted studies cast a wide net for any and all detectable metabolites in complex mixtures. Given the prevalence of OS during HIV infection and antiviral treatment, it is perhaps not surprising that indicators of this malady would become evident during metabolite identification. At times, targeted studies for specific (non-OS) metabolites would also yield OS markers as an outcome. This review examines the findings of these studies by first providing the necessary background information on OS and the main ways in which free radicals/reactive oxygen species (ROS) produced during OS, cause biomolecular damage. This is followed by information on the biomarkers which come about as a result of free radical damage and the techniques used for assaying these stress indicators. The established links between elevated ROS and lowered antioxidants during HIV infection and the subsequent use of HAART is then presented followed by a review of the OS markers detected in HIV metabonomic studies to date. We identify gaps in HIV/HAART-associated OS research and finally suggest how these research gaps can be addressed through metabonomic analysis, specifically targeting the multiple markers of HIV-induced OS.

A combined chemometric and quantitative NMR analysis of HIV/AIDS serum discloses metabolic alterations associated with disease status.

Individuals infected with the human immunodeficiency virus (HIV) often suffer from concomitant metabolic complications. Treatment with antiretroviral therapy has also been shown to alter the metabolism of patients. Although chemometric analysis of nuclear magnetic resonance (NMR) spectra of human sera can distinguish normal sera (HIVneg) from HIV-infected sera (HIVpos) and sera from HIV-infected patients on antiretroviral therapy (ART), quantitative analysis of the discriminating metabolites and their relationship to disease status has yet to be determined. The objectives of the study were to analyze NMR spectra of HIVneg, HIVpos, and ART serum samples with a combination of chemometric and quantitative methods and to compare the NMR data with disease status as measured by viral load and CD4 count. High-resolution magic angle spinning (HRMAS) NMR spectroscopy was performed on HIVneg (N = 10), HIVpos (N = 10), and ART (N = 10) serum samples. Chemometric linear discriminant analysis classified the three groups of spectra with 100% accuracy. Concentrations of 12 metabolites were determined with a semi-parametric metabolite quantification method named high-resolution quantum estimation (HR-QUEST). CD4 count was directly associated with alanine (p = 0.008), and inversely correlated with both glutamine (p = 0.017) and glucose (p = 0.022) concentrations. A multivariate linear model using alanine, glutamine and glucose as covariates demonstrated an association with CD4 count (p = 0.038). The combined chemometric and quantitative analysis of the data disclosed previously unknown associations between specific metabolites and disease status. The observed associations with CD4 count are consistent with metabolic disorders that are commonly seen in HIV-infected patients.

Metabonomic analysis of HIV-infected biofluids.

Monitoring the progression of HIV infection to full-blown acquired immune deficiency syndrome (AIDS) and assessing responses to treatment will benefit greatly from the identification of novel biological markers especially since existing clinical indicators of disease are not infallible. Nuclear magnetic resonance spectroscopy (NMR) and mass spectrometry (MS) are powerful methodologies used in metabonomic analyses for an approximation of HIV-induced changes to the phenotype of an infected individual. Although early in its application to HIV/AIDS, (biofluid) metabonomics has already identified metabolic pathways influenced by both HIV and/or its treatment. To date, biofluid NMR and MS data show that the virus and highly active antiretroviral treatment (HAART) mainly influence carbohydrate and lipid metabolism, suggesting that infected individuals are susceptible to very specific metabolic complications. A number of well-defined biofluid metabonomic studies clearly distinguished HIV negative, positive and treatment experienced patient profiles from one another. While many of the virus or treatment affected metabolites have been identified, the metabonomics measurements were mostly qualitative. The identities of the molecules were not always validated neither were the statistical models used to distinguish between groups. Assigning particular metabolic changes to specific drug regimens using metabonomics also remains to be done. Studies exist where identified metabolites have been linked to various disease states suggesting great potential for the use of metabonomics in disease prognostics. This review therefore examines the field of metabonomics in the context of HIV/AIDS, comments on metabolites routinely detected as being affected by the pathogen or treatment, explains what existing data suggest and makes recommendations on future research.