DRUG POLYMORPHISM IDENTIFICATION USING FOURIER TRANSFORM-RAMAN SPECTROSCOPY: A COMPARATIVE STUDY OF LAMIVUDINE AND FINASTERIDE DRUGS

Objectives: Maintaining the quality of the pharmaceutical drug product during its shelf life is highly desirable. The crystalline form of the drug having the great thermodynamic stability is essential for the manufacturers in pharmaceutical industry in view of their profit and also for the safety of the customer. Many pharmaceutical drugs have the tendency to exhibit polymorphism which is unwanted for pharmaceutical companies, where they have experienced market shortages due to these unpredicted polymorphic and/or pseudomorphic changes. The property of a drug exhibiting more than one crystal form is considerably regarded as polymorphism and each of the crystalline form has its own physicochemical properties, namely, solubility, heat capacity, melting point, and sublimation point. To relieve this ultimate effect on the drug quality and stability, a prior detection of polymorphism in the final dosage form is highly recommended. Hence, many analytical techniques have been proposed for the detection of polymorphism in pharmaceutical drug products. Methods: Fourier transform (FT)-Raman spectrometer is used for the investigation of drug polymorphism and the instrument is advanced with charge coupled device detectors, ease of sample preparation and handling, mitigation of sub-sampling problems using different geometric laser irradiance patterns and having different optical components of Raman spectrometers. Results: In this work, we carefully studied the Raman spectral patterns for Lamivudine as well as Finasteride drug substances for the detection of polymorphism. Further, we have highlighted the advantages of FT-Raman spectroscopy over other polymorphism detection techniques. For example, Raman spectra showed invariably sharp, well resolved bands compare to IR spectra due to the minor contribution of overtone vibrations in Raman spectra, resulting in much less broadening and a better resolution of bands. Besides, Raman spectroscopy does not suffer from the sampling problems that are common in X-ray powder diffraction, where preferred orientation and specimen displacements are serious restrictions for the application of quantitative method. Conclusion: Here, in this paper, we are presented and compared the experimental results regarding the detection of polymorphism in Lamivudine and Finasteride drugs using FT-Raman spectroscopy, to illustrate the advantages of the technique in the detection of polymorphism over other techniques

Antidiabetic, Antihyperlipidemic and Antioxidant Activities of Buchanania lanzan Spreng Methanol Leaf Extract in Streptozotocin-Induced Types I and II Diabetic Rats

Purpose: To evaluate the antidiabetic, antihyperlipidemic and antioxidant activities of Buchanania lanzan.Methods: Wistar rats were divided into nine groups of six animals each, and 40 mg/kg of streptozotocin or streptozotocin + nicotinamide was administered intraperitonially to induce types I and II diabetes. Those with blood glucose levels > 190 ± 8 mg/dl were administered the methanol leaf extract of Buchanania lanzan (MEBL, 100 or 200 mg/kg, p.o.) or positive control for 21 days. Blood glucose, lipid profile, antioxidant enzymes and oxidative stress markers were evaluated.Results: Following induction, blood glucose level rose to 327.7 ± 47.4 mg/dl, compared to the normal value of 910 ± 3.2 mg/dl. Administration of MEBL (100 or 200 mg/kg) significantly (p < 0.05) decreased blood glucose level, serum lipid profile, and significantly (p < 0.05) increased antioxidant activity as evidenced by increase in super oxide dismutase (SOD), catalas, glutathione (GSH), and decrease in the activity of lipid peroxidation (LPO).Conclusion: MEBL exhibits antidiabetic, antihyperlipidemic and antioxidant activities in diabetic rat and needs to be further investigated for the treatment of both types I and II diabetes mellitus.Keywords: Antidiabetic, Antihyperlipidemic, Antioxidant, Buchanania lanzan

Serine/threonine protein phosphatase 6 modulates the radiation sensitivity of glioblastoma

Increasing the sensitivity of glioblastoma cells to radiation is a promising approach to improve survival in patients with glioblastoma multiforme (GBM). This study aims to determine if serine/threonine phosphatase (protein phosphatase 6 (PP6)) is a molecular target for GBM radiosensitization treatment. The GBM orthotopic xenograft mice model was used in this study. Our data demonstrated that the protein level of PP6 catalytic subunit (PP6c) was upregulated in the GBM tissue from about 50% patients compared with the surrounding tissue or control tissue. Both the in vitro survival fraction of GBM cells and the patient survival time were highly correlated or inversely correlated with PP6c expression (R2=0.755 and −0.707, respectively). We also found that siRNA knockdown of PP6c reduced DNA-dependent protein kinase (DNA-PK) activity in three different GBM cell lines, increasing their sensitivity to radiation. In the orthotopic mice model, the overexpression of PP6c in GBM U87 cells attenuated the effect of radiation treatment, and reduced the survival time of mice compared with the control mice, while the PP6c knocking-down improved the effect of radiation treatment, and increased the survival time of mice. These findings demonstrate that PP6 regulates the sensitivity of GBM cells to radiation, and suggest small molecules disrupting or inhibiting PP6 association with DNA-PK is a potential radiosensitizer for GBM

Activation of DNA-PK by Ionizing Radiation Is Mediated by Protein Phosphatase 6

DNA-dependent protein kinase (DNA-PK) plays a critical role in DNA damage repair, especially in non-homologous end-joining repair of double-strand breaks such as those formed by ionizing radiation (IR) in the course of radiation therapy. Regulation of DNA-PK involves multisite phosphorylation but this is incompletely understood and little is known about protein phosphatases relative to DNA-PK. Mass spectrometry analysis revealed that DNA-PK interacts with the protein phosphatase-6 (PP6) SAPS subunit PP6R1. PP6 is a heterotrimeric enzyme that consists of a catalytic subunit, plus one of three PP6 SAPS regulatory subunits and one of three ankyrin repeat subunits. Endogenous PP6R1 co-immunoprecipitated DNA-PK, and IR enhanced the amount of complex and promoted its import into the nucleus. In addition, siRNA knockdown of either PP6R1 or PP6 significantly decreased IR activation of DNA-PK, suggesting that PP6 activates DNA-PK by association and dephosphorylation. Knockdown of other phosphatases PP5 or PP1γ1 and subunits PP6R3 or ARS-A did not reduce IR activation of DNA-PK, demonstrating specificity for PP6R1. Finally, siRNA knockdown of PP6R1 or PP6 but not other phosphatases increased the sensitivity of glioblastoma cells to radiation-induced cell death to a level similar to DNA-PK deficient cells. Our data demonstrate that PP6 associates with and activates DNA-PK in response to ionizing radiation. Therefore, the PP6/PP6R1 phosphatase is a potential molecular target for radiation sensitization by chemical inhibition

Tigers of Sundarbans in India: Is the Population a Separate Conservation Unit?

The Sundarbans tiger inhabits a unique mangrove habitat and are morphologically distinct from the recognized tiger subspecies in terms of skull morphometrics and body size. Thus, there is an urgent need to assess their ecological and genetic distinctiveness and determine if Sundarbans tigers should be defined and managed as separate conservation unit. We utilized nine microsatellites and 3 kb from four mitochondrial DNA (mtDNA) genes to estimate genetic variability, population structure, demographic parameters and visualize historic and contemporary connectivity among tiger populations from Sundarbans and mainland India. We also evaluated the traits that determine exchangeability or adaptive differences among tiger populations. Data from both markers suggest that Sundarbans tiger is not a separate tiger subspecies and should be regarded as Bengal tiger (P. t. tigris) subspecies. Maximum likelihood phylogenetic analyses of the mtDNA data revealed reciprocal monophyly. Genetic differentiation was found stronger for mtDNA than nuclear DNA. Microsatellite markers indicated low genetic variation in Sundarbans tigers (He= 0.58) as compared to other mainland populations, such as northern and Peninsular (Hebetween 0.67- 0.70). Molecular data supports migration between mainland and Sundarbans populations until very recent times. We attribute this reduction in gene flow to accelerated fragmentation and habitat alteration in the landscape over the past few centuries. Demographic analyses suggest that Sundarbans tigers have diverged recently from peninsular tiger population within last 2000 years. Sundarbans tigers are the most divergent group of Bengal tigers, and ecologically non-exchangeable with other tiger populations, and thus should be managed as a separate "evolutionarily significant unit" (ESU) following the adaptive evolutionary conservation (AEC) concept.Wildlife Institute of India, Dehra Dun (India)

Porphyromonas gingivalis–dendritic cell interactions: consequences for coronary artery disease

An estimated 80 million US adults have one or more types of cardiovascular diseases. Atherosclerosis is the single most important contributor to cardiovascular diseases; however, only 50% of atherosclerosis patients have currently identified risk factors. Chronic periodontitis, a common inflammatory disease, is linked to an increased cardiovascular risk. Dendritic cells (DCs) are potent antigen presenting cells that infiltrate arterial walls and may destabilize atherosclerotic plaques in cardiovascular disease. While the source of these DCs in atherosclerotic plaques is presently unclear, we propose that dermal DCs from peripheral inflamed sites such as CP tissues are a potential source. This review will examine the role of the opportunistic oral pathogen Porphyromonas gingivalis in invading DCs and stimulating their mobilization and misdirection through the bloodstream. Based on our published observations, combined with some new data, as well as a focused review of the literature we will propose a model for how P. gingivalis may exploit DCs to gain access to systemic circulation and contribute to coronary artery disease. Our published evidence supports a significant role for P. gingivalis in subverting normal DC function, promoting a semimature, highly migratory, and immunosuppressive DC phenotype that contributes to the inflammatory development of atherosclerosis and, eventually, plaque rupture

Paleo-Immunology: Evidence Consistent with Insertion of a Primordial Herpes Virus-Like Element in the Origins of Acquired Immunity

BACKGROUND:The RAG encoded proteins, RAG-1 and RAG-2 regulate site-specific recombination events in somatic immune B- and T-lymphocytes to generate the acquired immune repertoire. Catalytic activities of the RAG proteins are related to the recombinase functions of a pre-existing mobile DNA element in the DDE recombinase/RNAse H family, sometimes termed the "RAG transposon". METHODOLOGY/PRINCIPAL FINDINGS:Novel to this work is the suggestion that the DDE recombinase responsible for the origins of acquired immunity was encoded by a primordial herpes virus, rather than a "RAG transposon." A subsequent "arms race" between immunity to herpes infection and the immune system obscured primary amino acid similarities between herpes and immune system proteins but preserved regulatory, structural and functional similarities between the respective recombinase proteins. In support of this hypothesis, evidence is reviewed from previous published data that a modern herpes virus protein family with properties of a viral recombinase is co-regulated with both RAG-1 and RAG-2 by closely linked cis-acting co-regulatory sequences. Structural and functional similarity is also reviewed between the putative herpes recombinase and both DDE site of the RAG-1 protein and another DDE/RNAse H family nuclease, the Argonaute protein component of RISC (RNA induced silencing complex). CONCLUSIONS/SIGNIFICANCE:A "co-regulatory" model of the origins of V(D)J recombination and the acquired immune system can account for the observed linked genomic structure of RAG-1 and RAG-2 in non-vertebrate organisms such as the sea urchin that lack an acquired immune system and V(D)J recombination. Initially the regulated expression of a viral recombinase in immune cells may have been positively selected by its ability to stimulate innate immunity to herpes virus infection rather than V(D)J recombination Unlike the "RAG-transposon" hypothesis, the proposed model can be readily tested by comparative functional analysis of herpes virus replication and V(D)J recombination

Protease Activated Receptor Signaling Is Required for African Trypanosome Traversal of Human Brain Microvascular Endothelial Cells

Human African trypanosomiasis, or sleeping sickness, occurs when single-cell trypanosome protozoan parasites spread from the blood to brain over the blood-brain barrier (BBB). This barrier is composed of brain microvascular endothelial cells (BMECs) especially designed to keep pathogens out. Safe drugs for treating sleeping sickness are lacking and alternative treatments are urgently required. Using our human BMEC BBB model, we previously found that a parasite protease, brucipain, induced calcium activation signals that allowed this barrier to open up to parasite crossing. Because human BMECs express protease-activated receptors (PARs) that trigger calcium signals in BMECs, we hypothesized a functional link between parasite brucipain and BMEC PARs. Utilizing RNA interference to block the production of one type of PAR called PAR-2, we hindered the ability of trypanosomes to both open up and cross human BMECs. Using gene-profiling methods to interrogate candidate BMEC pathways specifically triggered by brucipain, several pathways that potentially link brain inflammatory processes were identified, a finding congruent with the known role of PAR-2 as a mediator of inflammation. Overall, our data support a role for brucipain and BMEC PARs in trypanosome BBB transmigration, and as potential triggers for brain inflammation associated with the disease

Tuberculosis chemotherapy: current drug delivery approaches

Tuberculosis is a leading killer of young adults worldwide and the global scourge of multi-drug resistant tuberculosis is reaching epidemic proportions. It is endemic in most developing countries and resurgent in developed and developing countries with high rates of human immunodeficiency virus infection. This article reviews the current situation in terms of drug delivery approaches for tuberculosis chemotherapy. A number of novel implant-, microparticulate-, and various other carrier-based drug delivery systems incorporating the principal anti-tuberculosis agents have been fabricated that either target the site of tuberculosis infection or reduce the dosing frequency with the aim of improving patient outcomes. These developments in drug delivery represent attractive options with significant merit, however, there is a requisite to manufacture an oral system, which directly addresses issues of unacceptable rifampicin bioavailability in fixed-dose combinations. This is fostered by the need to deliver medications to patients more efficiently and with fewer side effects, especially in developing countries. The fabrication of a polymeric once-daily oral multiparticulate fixed-dose combination of the principal anti-tuberculosis drugs, which attains segregated delivery of rifampicin and isoniazid for improved rifampicin bioavailability, could be a step in the right direction in addressing issues of treatment failure due to patient non-compliance

Biology of human hair: Know your hair to control it

Hair can be engineered at different levels—its structure and surface—through modification of its constituent molecules, in particular proteins, but also the hair follicle (HF) can be genetically altered, in particular with the advent of siRNA-based applications. General aspects of hair biology are reviewed, as well as the most recent contributions to understanding hair pigmentation and the regulation of hair development. Focus will also be placed on the techniques developed specifically for delivering compounds of varying chemical nature to the HF, indicating methods for genetic/biochemical modulation of HF components for the treatment of hair diseases. Finally, hair fiber structure and chemical characteristics will be discussed as targets for keratin surface functionalization