Publications by Ghulam Md Ashraf
Galectins are essential molecules that serve one of
the most important functions in life at the ... more Galectins are essential molecules that serve one of
the most important functions in life at the cellular level
recognition. Their expression and significant roles in
various biological pathways and physiological
process have been stamped in almost the taxa of
living world. The present book accounts for the basic
concepts of galectin biology, covering topics related
to their classification within the kingdoms of life and
their varied applications in various biological
pathways. To make the book more application
specific, the purification and extensive physico-
The free radical-mediated damage to proteins results in the modification of amino acid residues, ... more The free radical-mediated damage to proteins results in the modification of amino acid residues, cross-linking of side chains and fragmentation. L-tyrosine and protein bound tyrosine are prone to attack by various mediators and reactive nitrogen intermediates to form 3-nitrotyrosine (3-NT). 3-NT formation is also catalyzed by a class of peroxidases utilizing nitrite and hydrogen peroxide as substrates. Evidence supports the formation of 3-NT in vivo in diverse pathologic conditions and 3-NT is thought to be a relatively specific marker of oxidative damage. The formation of nitrotyrosine represents a specific peroxynitrite-mediated protein modification; thus, detection of nitrotyrosine in proteins is considered as a biomarker for endogenous peroxynitrite activity. Formation of tyrosine nitrated proteins is considered to be a post-translational modification with important pathophysiological consequences and is one of the markers of nitrosative stress that have been reported in neurodegeneration, inflammatory and other pathological conditions. -). The latter is considered to be the direct oxidant of peroxynitrite-mediated reagents in biological environments [43]. Peroxynitrite-mediated tyrosine nitration is also accelerated in the presence of transition metal ions, either in free form (Cu 2+ , Fe 3+ , Fe 2+ ) or as complexes involving protoporphyrin IX (heme) or certain chelators -ethylene diamine tetraacetic acid (EDTA) [15,16,44]. Hence, metal ions catalysis plays an important role in the nitration of protein residues in proteins [45].
Galectins are a family of galactose binding lectins that have become the focus of attention of ca... more Galectins are a family of galactose binding lectins that have become the focus of attention of cancer biologists due to their numerous regulatory roles in normal cellular metabolism and also because of their altered levels in various cancers. They are reportedly similar to several prominent and established modulators of apoptosis. In this review, we present a brief outline of the advancements in the methodology used to detect and identify them and their therapeutic applications in cancer. Their possible interactions with other glycoconjugates are also discussed and a vision for their future use in diagnosis and therapeutics is provided.
A soluble b-galactoside-binding lectin was purified by gel filtration chromatography from Bubalus... more A soluble b-galactoside-binding lectin was purified by gel filtration chromatography from Bubalus bubalis heart. Its metal-independent nature, molecular weight of 14.5 kDa, preferential affinity for b-D-lactose, and 87-92% identity with carbohydrate recognition domain of previously reported galectin-1 confirmed its inclusion in galectin-1 subfamily. Stokes radii determination using gel filtration under reducing and non-reducing conditions revealed its homo-dimeric nature, further confirming its Gal-1 nomenclature. The purified lectin was found to be the most stable mammalian heart galectin purified till date, suggesting its preferential use in various recognition studies. Treatment of the purified lectin with oxidizing agent, thiol blocking reagents, denaturants, and detergents resulted in significant changes in UV-VIS, fluorescence, CD and FTIR spectra, which strongly emphasized the important aspect of regular secondary structure of galectins for the maintenance of their active conformation. Reduction of the activity of the purified lectin after oxidation by H 2 O 2 , with remarkable fluorescence quenching, may suggest potential role for galectin-1 in free radical-induced, oxidative stress-mediated cardiovascular disorders. The predictions of bioinformatics studies were found to be in accordance with the results obtained in wet lab.
A soluble b-galactoside binding 14.5 kDa lectin was purified from the heart of Capra hircus. Its ... more A soluble b-galactoside binding 14.5 kDa lectin was purified from the heart of Capra hircus. Its metal independent nature, preferential affinity for b-D-lactose and 90-94% homology with carbohydrate recognition domain of previously reported galectin-1 confirmed its inclusion in galectin-1 subfamily. The secondary structures of the deduced amino acid sequences were generally conserved with previously reported Gal-1. Exposure of the purified protein to varying temperature and pH, oxidant, thiol blocking reagents, denaturants and detergents resulted in significant changes in UV (ultraviolet), fluorescence, CD (circular dichroism) and FTIR (fourier transform infra red) spectra, thus strongly emphasizing the vitality of regular secondary structure of galectins for maintaining their active conformation. Bioinformatics studies corroborated the results obtained in wet lab. Our findings based on physicochemical properties, oxidative inactivation and structural analysis of the goat heart galectin-1 suggests significant implications in potential biological and clinical applications.
Brain is a target of stress along with the immune, metabolic, and cardiovascular systems of the b... more Brain is a target of stress along with the immune, metabolic, and cardiovascular systems of the body. In the present work, the preventive roles of a multivitamin-mineral supplement and vitamins (E+C) in chronic unpredictable stress (CUS)-induced oxidative damage were studied in the brain and heart of Swiss albino mice. Thirty-two mice were randomized to one of the following groups: control+vehicle, CUS+vehicle, CUS+ multivitamin-mineral, and CUS+vitamins (E+C). CUS was applied for 4 weeks, and multivitamin-mineral and vitamins (E+C) were administered orally for the same period. CUS led to a negative impact on all the biochemical parameters analyzed. Elevation in malondialdehyde and reduction in glutathione levels were found. The activities of superoxide dismutase, catalase, glutathione S-transferase, and glutathione reductase were decreased. Treatment with multivitamin-mineral and vitamins (E+C) brought these parameters to near normal levels. Multivitamin-mineral was found more restitutive than combined vitamins (E+C) doses. The present study hypothesizes that supplementation with a multivitamin-mineral may prove more effective than vitamin treatment alone in the alleviation of oxidative damage in brain and heart during periods of chronic stress.
Mutagenicity is the capability of a chemical to carry out mutations in genetic material of an org... more Mutagenicity is the capability of a chemical to carry out mutations in genetic material of an organism. In order to curtail expensive drug failures due to mutagenicity found in late development or even in clinical trials, it is crucial to determine potential mutagenicity problems as early as possible. In this work we have proposed three different classifiers, i.e. Support Vector Machine (SVM), Artificial Neural Network (ANN) and Bayesian classifiers, for the prediction of mutagenicity of compounds based on seventeen descriptors. Among the three classifiers Radial Basis Function (RBF) kernel based SVM classifier appeared to be more accurate for classifying the compounds under study on mutagens and non-mutagens. The overall prediction accuracy of SVM model was found to be 71.73% which was appreciably higher than the accuracy of ANN based classifier (59.72%) and Bayesian classifier (66.61%). It suggests that SVM based prediction model can be used for predicting mutagenicity more accurately compared to ANN and Bayesian classifier for data under consideration.
Oral Bioavailability is the rate and extent to which an active drug substance is absorbed and bec... more Oral Bioavailability is the rate and extent to which an active drug substance is absorbed and becomes available to the general circulation. A computational model for the prediction of oral bioavailability is a vital initial step in the drug discovery. It is decisive for selecting the promising compounds for the next level optimizations and recognition for the clinical trials. In the present investigation we aimed to perform the oral bioavailability prediction by comparing three machine learning methods i.e. Support Vector Machine (SVM) based kernel learning, Artificial Neural Network (ANN) and Bayesian classification approach. The overall prediction efficiency of SVM based model for the test set was 96.85%, whereas according to the Bayesian classifier and ANN methods prediction efficiency was found to be 92.19% and 94.53% respectively. Thus the present results clearly suggested that the SVM based prediction of oral bioavailability of drugs is more efficient binary classification approach for the data under consideration.
Therapies targeting central stress mechanisms are fundamental for the development of successful t... more Therapies targeting central stress mechanisms are fundamental for the development of successful treatment strategies. Ocimum sanctum (OS) is an Indian medicinal plant traditionally used for the treatment of various stress-related conditions. Previously, we have isolated and characterized three OS compounds; Ocimarin, Ocimumoside A and Ocimumoside B. However, their role in modulating chronic stress-induced central changes is unexplored. Thus, in the present study the efficacy of these OS compounds have been evaluated on the chronic unpredictable stress (CUS)-induced alterations in the monoaminergic and antioxidant systems in the frontal cortex, striatum and hippocampus, along with the changes in the plasma corticosterone levels. CUS (two different types of stressors daily for seven days) resulted in a significant elevation of plasma corticosterone level, which was reversed to control levels by pretreatment with Ocimumoside A and B (40 mg/kg p.o.), while Ocimarin showed no effect. The levels of NA, DA and 5-HT were significantly decreased in all the three brain regions by CUS, with a selective increase of DA metabolites. A significant decrease in the glutathione (GSH) content, the activities of superoxide dismutase and catalase with a significant increase in the glutathione peroxidase activity and lipid peroxidation was observed in all the three regions of the brain by CUS. The OS compounds alone did not cause any significant change in the baseline values of these parameters. However, Ocimumoside A and B (40 mg/kg body p.o.) attenuated these CUS-induced alterations with an efficacy similar to that of standard anti-stress (Panax quinquefolium; 100 mg/kg p.o.) and antioxidant (Melatonin; 20 mg/kg i.p.) drugs. While, Ocimarin failed to modulate these CUS-induced alterations. Therefore, this is the first report which identified the anti-stress activity of novel Ocimumoside A and B at the level of central monoamines and antioxidant properties, implicating their therapeutic importance in the prevention of stress-related disorders.
Stress-induced changes in the monoaminergic system and subsequent enhancement of oxidative load a... more Stress-induced changes in the monoaminergic system and subsequent enhancement of oxidative load are associated with a wide range of central and peripheral disorders 1-3 . Exposure to a single session of severe uncontrollable foot shock was reported to cause protracted changes in dogs and rats, which are now characterized as anxiety and depression-like changes 4 . Reports also suggested alterations in the physiological parameters like body temperature, locomotion and exploratory behaviour 5 , hypothalamus-pituitary-adrenal (HPA)-axis 2 and brain neurotransmitters 5,6 in animals acutely exposed to unfamiliar stress. However, there is little information regarding the acute stressinduced central oxidative changes in terms of their initial response and vulnerability in different brain regions and the ABSTRACT: Background and Purpose: Stress-induced central effects are regulated by brain neurotransmitters, glucocorticoids and oxidative processes. Therefore, we aimed to evaluate the simultaneous alterations in the monoamine and antioxidant systems in selected brain regions (frontal cortex, striatum and hippocampus) at 1 hour (h) and 24h following the exposure of restraint stress (RS), to understand their initial response and possible crosstalk. Methods and Results: RS (150 min immobilization) significantly increased the dopamine levels in the frontal cortex and decreased them in the striatum and hippocampus, with selective increase of dopamine metabolites both in the 1h and 24h RS groups compared to control values. The serotonin and its metabolite levels were significantly increased in both time intervals, while noradrenaline levels were decreased in the frontal cortex and striatum only. The activities of superoxide dismutase, glutathione peroxidase and the levels of lipid peroxidation were significantly increased with significant decrease of glutathione levels in the frontal cortex and striatum both in the 1h and 24h RS groups. There was no significant change in the catalase activity in any group. In the hippocampus, the glutathione levels were significantly decreased only in the 1h RS group. Conclusions: Our study implies that the frontal cortex and striatum are more sensitive to oxidative burden which could be related to the parallel monoamine perturbations. This provides a rational look into the simultaneous compensatory central mechanisms operating during acute stress responses which are particular to precise brain regions and may have long lasting effects on various neuropathological alterations.
Cancer is a highly complex disease to understand, because it entails multiple cellular physiologi... more Cancer is a highly complex disease to understand, because it entails multiple cellular physiological systems. The most common cancer treatments are restricted to chemotherapy, radiation and surgery. Moreover, the early recognition and treatment of cancer remains a technological bottleneck. There is an urgent need to develop new and innovative technologies that could help to delineate tumor margins, identify residual tumor cells and micrometastases, and determine whether a tumor has been completely removed or not. Nanotechnology has witnessed significant progress in the past few decades, and its effect is widespread nowadays in every field. Nanoparticles can be modified in numerous ways to prolong circulation, enhance drug localization, increase drug efficacy, and potentially decrease chances of multidrug resistance by the use of nanotechnology. Recently, research in the field of cancer nanotechnology has made remarkable advances. The present review summarizes the application of various nanotechnology-based approaches towards the diagnostics and therapeutics of cancer.
New Delhi metallo-β-lactamase (NDM-1) is a serious threat to the existing antibiotic armory, and ... more New Delhi metallo-β-lactamase (NDM-1) is a serious threat to the existing antibiotic armory, and a potent weapon for bacteria to aid in in their 'battle'. It has the ability to inactivate all β-lactams, except aztreonam. However, most of the NDM-1-producers also produce aztreonam hydrolysing-β-lactamases, thereby making these pathogens absolutely resistant to all β-lactams. This minireview incorporates a concise update on global epidemiology (2009-2012) of NDM-1. However, the crux of the discussion is to focus on paucity of clinically useful therapeutic options, and suggest a solution to the drug resistance threat imposed by NDM-1 bacterial enzyme. The manuscript presents a 'region-specific treatment strategy' in a lucid flowchart format. The flowchart which lies at the interface of clinical microbiology and bioinformatics is expected to be useful in containing the problem of drug resistance due to NDM-1-producing bacterial pathogens.
Alzheimer disease (AD) is the most common dementing illness. Metabolic defects in the brain with ... more Alzheimer disease (AD) is the most common dementing illness. Metabolic defects in the brain with aging contribute to the pathogenesis of AD. These changes can be found systematically and thus can be used as potential biomarkers. Erythrocytes (RBCs) are passive "reporter cells" that are not well studied in AD. In the present study, we analyzed an array of glycolytic and related enzymes and intermediates in RBCs from patients with AD and non-Alzheimer dementia (NA), age-matched controls (AC) and young adult controls (YC). AD is characterized by higher activities of hexokinase, phosphofructokinase, and bisphosphoglycerate mutase and bisphosphoglycerate phosphatase in RBCs. In our study, we observed that glycolytic and related enzymes displayed significantly lower activities in AC. However, similar or significantly higher activities were observed in AD and NA groups as compared to YC group. 2,3diphosphoglycerate (2,3-DPG) levels were significantly decreased in AD and NA patients. The pattern of changes between groups in the above indices strongly correlates with each other. Collectively, our data suggested that AD and NA patients are associated with chronic disturbance of 2,3-DPG metabolism in RBCs. These defects may play a pivotal role in physiological processes, which predispose elderly subjects to AD and NA.
Uploads
Publications by Ghulam Md Ashraf
the most important functions in life at the cellular level
recognition. Their expression and significant roles in
various biological pathways and physiological
process have been stamped in almost the taxa of
living world. The present book accounts for the basic
concepts of galectin biology, covering topics related
to their classification within the kingdoms of life and
their varied applications in various biological
pathways. To make the book more application
specific, the purification and extensive physico-
the most important functions in life at the cellular level
recognition. Their expression and significant roles in
various biological pathways and physiological
process have been stamped in almost the taxa of
living world. The present book accounts for the basic
concepts of galectin biology, covering topics related
to their classification within the kingdoms of life and
their varied applications in various biological
pathways. To make the book more application
specific, the purification and extensive physico-