Glycoxidation of mammalian whole histone generates highly immunogenic aggregates: Sera of SLE patients contain autoantibodies against aggregates.

Non-enzymatic glycation and oxidation of self-proteins, causing formation and accumulation of advanced glycation end products (AGEs), have been reported in an array of pathologies, including systemic lupus erythematosus (SLE). Such modifications may generate neo-epitopes, break immunological tolerance, and induce antibody response. In this study, we have first analysed the structural modifications of whole histone in the presence of deoxyribose followed by oxidation with hydroxyl radicals. Changes in the secondary and tertiary structure of the whole histone were determined by spectroscopic techniques and biochemical assays. Fluorescence spectroscopy and UPLC-MS showed the generation of AGEs such as carboxymethyl lysine and pentosidine, while DLS and TEM indicated the presence of amorphous AGE-aggregates. Moreover, rabbits immunized with these histone-AGEs exhibited enhanced immunogenicity and ELISA and western immunoblot of IgG antibodies from SLE patients' sera showed a significantly higher specificity towards modified histone-AGEs than the native histone.

Pharmacology teaching in dental education in India: Time for a reappraisal.

India has a unique position with its vast population and rapidly increasing healthcare demand. Dental health is integral to a holistic health care need, and a robust dental education system is necessary. Dental education in India is mainly regulated by the Dental Councilof India, setting broad guidelines. Universities having dental colleges and institutes develop fine curriculum development and evaluation details. General and Dental Pharmacology and Therapeuticsis a crucial subject taught to undergraduate dental students during the second year of a 4-year duration course. A dental graduate should be well trained in general and systemic pharmacology and rational therapeutics principles. This has been set as an objective by the Dental Council of India. Sound knowledge of the drug action mechanisms, indications, adverse drug reactions, drug interactions and contraindications, evidence-based medicine, and rational use of adrug is core to the allopathic system. The practical exercises on human simulation or computer-assisted learning are critical for understanding pharmacology. The subject of pharmacology for dental graduates has been allotted 70 hours of theory and 20 hours of practicals with almost the same syllabus as medical graduates. This article highlights the areas of concern concerning the deficiency of teaching hours and needed improvement in the curriculum to make it competent to achieve its objective. The authors bring this much-needed topic for discussion among academicians and for the attention of regulatory authorities.

New Horizons in the Treatment of Neurological Disorders with Tailorable Gold Nanoparticles.

Neurological disorders, such as epilepsy, dementia, Parkinson's disease and Alzheimer's disease, occur due to disorganization of the neurons in the nervous system. Disturbances in the nervous system cause problems with the memory, senses and moods. In order to treat such disorders, scientists have been working extensively, utilizing different approaches. Nanoneurotechnology has emerged as a promising tool to manage these complicated disorders, where nanoparticles with their tunable properties such as size, shape, increased solubility, biodegradability, surface area and sharp penetration through the biological barriers, target the central nervous system. This technology targets damaged neurons without affecting healthy neurons and the Blood-Brain Barrier (BBB). In this review, we discuss neurological disorders and challenges in their diagnosis and treatment by emphasizing on the role of tailorable gold nanoparticles in therapeutic drug approaches.

Anti-Cancer Effect of Gingerol in Cancer Prevention and Treatment.

Cancer is one of the most lethal diseases in the world. Because of the high death rate associated with cancer and the side effects of chemotherapy and radiation therapy, patients require alternative strategies for its treatment. Ginger (Zingiber officinale) has enormous medicinal properties and health benefits. In this review, we discuss the basic mechanism by which gingerol (an active component of ginger) modulates a variety of cell signaling pathways linked to cancer, including Nuclear Factors (NF-κB), Signal Transducer and Activator of Transcription 3 (STAT3), Activator Protein-1 (AP-1), ß-catenin, Growth Factors Receptors (EGFR, VEGFR); Mitogen-Activated Protein Kinases (MAPK) and pro-inflammatory mediators (TNF-α and COX-2). Both in vitro and in vivo studies support the role of gingerol in cancer. The efficacy of gingerol by clinical trials has also been reported. Importantly, natural agents are already in clinical trials against various kinds of cancer. An effort has been made through this comprehensive review to highlight the recent developments and milestones achieved in cancer therapies via studies based on different cell lines using gingerol.

Peroxynitrite-Mediated Structural Changes in Histone H2A: Biochemical and Biophysical Analysis.

BACKGROUND: Peroxynitrite, a nitrating and oxidizing agent, is formed by the interaction between nitric oxide and superoxide radicals. H2A histone is a basic nucleoprotein and is one of the major core histones responsible for packaging DNA. It has been shown that they are highly sensitive to oxidizing and nitrating agents. OBJECTIVE: Nitration of tyrosine residues in proteins by peroxynitrite is regarded as a marker of nitrosative damage. The dityrosine bond, an oxidative covalent cross-link between two tyrosines in protein, is increasingly identified as a marker of oxidative stress, aging and neurodegerative diseases. METHODS: Peroxinitrite-mediated nitration and dinitration in H2A histone was assessed by various biophysical techniques. RESULTS: The data presented in this study showed that the dityrosine content was found to be elevated in H2A histone modified with peroxynitrite. The formation of dityrosine showed a decrease in fluorescence intensity, generation of a new peak in FT-IR, increase in hydrodynamic size, and loss of secondary and tertiary structure of H2A resulting in a partially folded structure. CONCLUSION: We report that H2A may undergo conformational and structural changes under nitrosative and oxidative stress from the deleterious effects of peroxynitrite.

Physicochemical Characterization of Curcumin Loaded Chitosan Nanoparticles: Implications in Cervical Cancer.

BACKGROUND: Curcumin is a potent anticancer agent and has great potential efficacy against different types of cancers. A major disadvantage of curcumin, however, is its poor solubility and bioavailability. OBJECTIVE: The aim of the present work is to synthesize chitosan and curcumin-loaded chitosan nanoparticles and their characterization through various physicochemical methods and cellular uptake in cervical cancer cell line SiHa. METHOD: Chitosan nanoparticles were synthesized through the method of ionic gelation of chitosan with sodium Tripolyphosphate (TPP). In addition, the internal structure of chitosan nanoparticles and curcumin loaded chitosan nanoparticles were characterized by DLS, UV-Visible spectrophotometer, DSC, LCMS and LDH assay. RESULTS: The studies presented demonstrate that curcumin-loaded chitosan nanoparticles showed increased uptake in the SiHa cells as compared to free curcumin and chitosan nanoparticles did not show any significant uptake in SiHa cell line. The curcumin-loaded chitosan nanoparticles released more lactate and lower ATP as compared to native curcumin in cervical cancer lines such as SiHa, CaSki and HeLa. CONCLUSION: Thus, chitosan based curcumin nanoparticles could be used as a potent vector / delivery agent for drug targeting in the treatment of cervical cancer.

Impact of Hydroxyl Radical Modified-Human Serum Albumin Autoantigens in Systemic Lupus Erythematosus.

Free radicals are important mediators for cell toxicity and pathogenesis of diseases. Reactive oxygen species (ROS) have been generated broadly in inflammatory diseases including autoimmune diseases. ROS have been not only associated with the initiation and progression of the autoimmune response but also in amplification and exploring to novel epitopes, through the unveiling of antigenic determinants. This review explores the involvement of ROS in the pathophysiology of non-organ specific autoimmune diseases like systemic lupus erythematosus (SLE). The modification of human serum albumin through hydroxyl radical is thought to be responsible for the induction of autoantibodies against modified human serum albumin. In the light of overwhelming evidence suggesting the association with oxidative damage in autoimmunity, the administration of antioxidants could be a viable alternative for the neutralization of free radicals that are involved in eliciting autoimmune disease. In this review, we have discussed their pro-oxidant as well anti-oxidant properties which are capable of differentially modulating the autoimmune response.

Genotoxic effect and antigen binding characteristics of SLE auto-antibodies to peroxynitrite-modified human DNA.

Systemic lupus erythematosus (SLE) is an inflammatory autoimmune disease characterized by auto-antibodies against native deoxyribonucleic acid after modification and is one of the reasons for the development of SLE. Here, we have evaluated the structural perturbations in human placental DNA by peroxynitrite using spectroscopy, thermal denaturation and high-performance liquid chromatography (HPLC). Peroxynitrite is a powerful potent bi-functional oxidative/nitrative agent that is produced both endogenously and exogenously. In experimental animals, the peroxynitrite-modified DNA was found to be highly immunogenic. The induced antibodies showed cross-reactions with different types of DNA and nitrogen bases that were modified with peroxynitrite by inhibition ELISA. The antibody activity was inhibited by approximately 89% with its immunogen as the inhibitor. The antigen-antibodies interaction between induced antibodies with peroxynitrite-modified DNA showed retarded mobility as compared to the native form. Furthermore, significantly increased binding was also observed in SLE autoantibodies with peroxynitrite-modified DNA than native form. Moreover, DNA isolated from lymphocyte of SLE patients revealed significant recognition of anti-peroxynitrite-modified DNA immunoglobulin G (IgG). Our data indicates that DNA modified with peroxynitrite presents unique antigenic determinants that may induce autoantibody response in SLE.

Nitration of H2B histone elicits an immune response in experimental animals.

Histone H2B is an autoantigen that appears in circulation due to altered apoptosis/or insufficient clearance and is likely to be involved in the induction and progression of autoimmune diseases since modified-H2B is immunogenic. Our studies demonstrate that tyrosines of H2B histone spontaneously converts to free and nitrotyrosine bound protein in vivo. Commercially available H2B histone was modified with peroxynitrite in vitro. Modified H2B was found to be more immunogenic than native form in experimental animals. Furthermore, the sera of rabbits were analyzed for the native and modified forms of the H2B histone. The binding specificity of autoantibodies was characterized by competitive enzyme-linked immunosorbent assay (ELISA) and band shift assay. The free 3-nitrotyrosine in systemic lupus erythematosus sera was quantified by high-performance liquid chromatography. Peroxynitrite-modified H2B induced high titre antibodies as compared to native form which were directly proportional to the nitrotyrosine content. Furthermore, the induced antibodies showed specificity towards the immunogen and cross-reacted with tyrosine-nitrated proteins. ELISA showed preferential binding of induced anti-peroxynitrite modified H2B antibodies to modified H2B as compared to native H2B. The present study shows that peroxynitrite modification of self-antigen(s) generates neoepitopes capable of inducing modified-H2B autoantibodies in experimental animals.

Peroxynitrite-modified histone as a pathophysiological biomarker in autoimmune diseases.

Under physiological conditions, reactive nitrogen and oxygen species are produced continuously. However, excess of these radicals may damage biomolecules like lipids, proteins and nucleic acids. These reactive species have been implicated in many disease conditions including acute/chronic inflammation, rheumatoid arthritis (RA), neurodegenerative diseases and systemic lupus erythematosus (SLE). Peroxynitrite, an oxidant and nitrating molecule, formed in in vivo, when nitric oxide reacts with superoxide radical. The abnormal levels of nitrotyrosine detected in tissues affected by autoimmune diseases have been attributed to peroxynitrite-mediated enhanced nitration of tyrosine residues in proteins. The chromosomal histone proteins are conserved and weak immunogens. However, they exhibit strong immunogenicity after nitration. Rabbits challenged with peroxynitrite-modified histone induce high titre antibodies, indicating that peroxynitrite modification generated immunogenic epitopes. The preferential binding of peroxynitrite-modified histones by autoantibodies derived from SLE and RA sera shows oxidatively and nitrated modified histones involve in the initiation and progression of autoimmune diseases. This review article presents the literature review of the physicochemical and immunological studies on histone proteins modified with peroxynitrite with an objective of the possible role of oxidatively nitrated histones in the initiation/progression of autoimmune inflammatory diseases.

Characterization and carboplatin loaded chitosan nanoparticles for the chemotherapy against breast cancer in vitro studies.

Aim of the studies to synthesized chitosan nanoparticles by an ionic interaction procedure. The nanoparticles were characterized by physicochemical methods like, DLS, TEM, Surface potential measurements, FT-IR and DSC. The average particle size of chitosan and carboplatin nanoparticles was found to be 277.25±11.37nm and 289.30±8.15nm and zeta potential was found to be 31±3.14mV and 33±2.15mV respectively with low polydispersity index. The maximum entrapment of carboplatin in nanoparticles was a spherical shape with a positive charge. The maximum encapsulation and loading efficiencies of carboplatin (5mg/ml) were obtained to be 58.43% and 13.27% respectively. The nanocarboplatin was better blood compatibility as compared to chitosan nanoparticles. Finally, the cytotoxic effects of the carboplatin loaded chitosan nanoparticles were tested in-vitro against breast cancer (MCF-7) cell lines. Our studies showed that the chitosan nanoparticles could be used as a promising candidate for drug delivery for the therapeutic treatment of breast cancer.

Characterization and anti-proliferative activity of curcumin loaded chitosan nanoparticles in cervical cancer.

In the present study the chitosan nanoparticles (CsNPs) and curcumin loaded chitosan nanoparticles (CLCsNPs) were synthesized by tripolyphosphate (TPP) cross-linking method. The nanoparticles were prepared within a zone of appropriate chitosan and TPP concentrations. The average size of CsNPs and CLCsNPs were approximately 189±11.8nm and 197±16.8nm, exhibited a zeta potential of +76±5.6mV and +71±6.4mV respectively and drug entrapment efficiency was ≈85%. The CLCsNPs and CsNPs were further characterized by different physicochemical methods like transmission electron microscopy (TEM), dynamic light scattering (DLS), HPLC, MALDI-TOF, FT-IR, XRD and UV-vis Spectroscopy. In vitro studies revealed a fast release of ≈35% at pH 5 and ≈25% at pH 7.4 of the drug during the first 3h, followed by controlled release of curcumin over a period of 120h and sustained anti-proliferative activity of the drug in a dose and time dependent manner of CLCsNPs and combination with methyl jasmonate. The higher cytotoxicity effect of CLCsNPs may be due to their higher cellular uptake as compared to curcumin. Chitosan nanoparticles were not only stable but also a nontoxic. Our data suggested that curcumin loaded nanoformulations, therefore, might be promising candidates in cancer therapy.