19 results on '"Amitava Khan"'
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2. Death to Memory Cells: Case of Hypogammaglobulinemia
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Amitava Khan and D. Das
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Hypogammaglobulinemia ,business.industry ,Immunology ,Medicine ,business ,medicine.disease - Published
- 2021
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3. An association study of severity of intellectual disability with peripheral biomarkers of disabled children in a rehabilitation home, Kolkata, India
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Swapan Mukherjee, Samrat Saha, Anup K. Sadhu, Amitava Khan, Tapashi Mitra, Saurabh Ghosh, Sushobhan Biswas, Suhrita Paul, Siddhartha Datta, Sanjit Dey, Krishnendu Manna, Tuhin Bhattacharya, Aaveri Sengupta, Rakhi Dey Sharma, and Ujjal Das
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Male ,medicine.medical_specialty ,Erythrocytes ,Adolescent ,Homocysteine ,Psychometrics ,medicine.medical_treatment ,lcsh:Medicine ,Neurophysiology ,India ,macromolecular substances ,medicine.disease_cause ,Severity of Illness Index ,Peripheral blood mononuclear cell ,Article ,chemistry.chemical_compound ,Neurotrophic factors ,Intellectual Disability ,Internal medicine ,Intellectual disability ,Severity of illness ,Humans ,Medicine ,lcsh:Science ,Child ,Disability ,Multidisciplinary ,Rehabilitation ,business.industry ,lcsh:R ,medicine.disease ,Disabled Children ,chemistry ,Child, Preschool ,lcsh:Q ,Lipid Peroxidation ,business ,Biomarkers ,Oxidative stress - Abstract
The current investigation has identified the biomarkers associated with severity of disability and correlation among plethora of systemic, cellular and molecular parameters of intellectual disability (ID) in a rehabilitation home. The background of study lies with the recent clinical evidences which identified complications in ID. Various indicators from blood and peripheral system serve as potential surrogates for disability related changes in brain functions. ID subjects (Male, age 10 ± 5 yrs, N = 45) were classified as mild, moderate and severe according to the severity of disability using standard psychometric analysis. Clinical parameters including stress biomarkers, neurotransmitters, RBC morphology, expressions of inflammatory proteins and neurotrophic factor were estimated from PBMC, RBC and serum. The lipid peroxidation of PBMC and RBC membranes, levels of serum glutamate, serotonin, homocysteine, ROS, lactate and LDH-A expression increased significantly with severity of ID whereas changes in RBC membrane β-actin, serum BDNF, TNF-α and IL-6 was found non-significant. Structural abnormalities of RBC were more in severely disabled children compared to mildly affected ones. The oxidative stress remained a crucial factor with severity of disability. This is confirmed not only by RBC alterations but also with other cellular dysregulations. The present article extends unique insights of how severity of disability is correlated with various clinical, cellular and molecular markers of blood. This unique study primarily focuses on the strong predictors of severity of disability and their associations via brain-blood axis.
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- 2019
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4. Transpalpebral extrusion of solid silicone buckle
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Abadan Amitava Khan
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Explants ,reattachment surgery ,transpalpebral extrusion ,Ophthalmology ,RE1-994 - Abstract
Explants used in retinal reattachment surgery occasionally extrude. Cheese-wiring of the suture through the sclera consequent to raised intraocular pressure allows the buckle to loosen and/or unfold. Subsequent infection, often with Staphylococcus albus, accelerates the process of extrusion. Commonly, such explants are of silicone sponge. The reported case is unusual in that the extrusion occurred through the upper lid, and involved a solid silicone explant.
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- 2009
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5. Ferulic acid (FA) abrogates γ-radiation induced oxidative stress and DNA damage by up-regulating nuclear translocation of Nrf2 and activation of NHEJ pathway
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Amitava Khan, Sushobhan Biswas, Ujjal Das, Mahuya Sinha, Anindita Chakraborty, Krishnendu Manna, Sanjit Dey, and Aaveri Sengupta
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Male ,Transcriptional Activation ,0301 basic medicine ,DNA End-Joining Repair ,Coumaric Acids ,NF-E2-Related Factor 2 ,DNA damage ,Drug Evaluation, Preclinical ,Radiation-Protective Agents ,medicine.disease_cause ,Composite Resins ,Biochemistry ,Mice ,03 medical and health sciences ,Picrates ,medicine ,Animals ,DNA-PKcs ,chemistry.chemical_classification ,Reactive oxygen species ,biology ,Super oxide dismutase ,Superoxide Dismutase ,Biphenyl Compounds ,Free Radical Scavengers ,General Medicine ,Catalase ,Molecular biology ,Non-homologous end joining ,Oxidative Stress ,030104 developmental biology ,chemistry ,Gamma Rays ,biology.protein ,Oxidation-Reduction ,GADD45A ,Oxidative stress ,DNA Damage ,Plasmids ,Signal Transduction - Abstract
The present study was aimed to evaluate the radioprotective effect of ferulic acid (FA), a naturally occurring plant flavonoid in terms of DNA damage and damage related alterations of repair pathways by gamma radiation. FA was administered at a dose of 50 mg/kg body weight for five consecutive days prior to exposing the swiss albino mice to a single dose of 10 Gy gamma radiation. Ionising radiation induces oxidative damage manifested by decreased expression of Cu, Zn-SOD (SOD stands for super oxide dismutase), Mn-SOD and catalase. Gamma radiation promulgated reactive oxygen species (ROS) mediated DNA damage and modified repair pathways. ROS enhanced nuclear translocation of p53, activated ATM (ataxia telangiectasia-mutated protein), increased expression of GADD45a (growth arrest and DNA-damage-inducible protein) gene and inactivated Non homologous end joining (NHEJ) repair pathway. The comet formation in irradiated mice peripheral blood mononuclear cells (PBMC) reiterated the DNA damage in IR exposed groups. FA pretreatment significantly prevented the comet formation and regulated the nuclear translocation of p53, inhibited ATM activation and expression of GADD45a gene. FA promoted the nuclear translocation of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and activated NHEJ repair pathway to overcome ROS mediated oxidative stress and DNA damage. Therefore, the current study stated that FA can challenge the oxidative stress by (i) inducing nuclear translocation of Nrf2, (ii) scavenging ROS, and (iii) activating NHEJ DNA repair process.
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- 2017
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6. Naringin ameliorates radiation-induced hepatic damage through modulation of Nrf2 and NF-κB pathways
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Sanjit Dey, Amitava Khan, Anindita Chakraborty, Dipanwita Mukherjee, Sushobhan Biswas, Aaveri Sengupta, Krishnendu Manna, and Ujjal Das
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0301 basic medicine ,Programmed cell death ,Chemistry ,Kinase ,General Chemical Engineering ,NF-κB ,General Chemistry ,Molecular biology ,03 medical and health sciences ,chemistry.chemical_compound ,030104 developmental biology ,Biochemistry ,Apoptosis ,TBARS ,Protein kinase A ,Protein kinase B ,PI3K/AKT/mTOR pathway - Abstract
Understanding the mechanism of ionizing radiation (IR)-induced systemic stress and its modulation by phytocomponents has great significance for the development of novel phyto-radioprotectors. The present study was intended to evaluate the radioprotective effect of naringin (NG), a citrus flavonoid on the modulation of IR-induced activation of the redox-regulated signaling system in murine liver. On the basis of survival analysis, mice were treated with 75 mg kg−1 body weight of NG for three consecutive days before irradiation (6 Gy). Pretreatment with NG significantly prevented the IR-induced generation of intracellular reactive oxygen species (ROS), along with the formation of hepatic thiobarbituric acid reactive substances (TBARS) and cellular nitrite. NG also showed significant reduction in IR-induced nuclear DNA damage through the inhibition of DNA-dependent protein kinase (DNA-PK). Further, the IR-induced cell death was arrested in the presence of NG through the inhibition of p53 mediated stress-activated protein kinase/Jun amino-terminal kinase (SAPK/JNK) pathways and modulation of other molecules of apoptosis pathways. Moreover, NG supported the intracellular defense mechanisms, by maintaining the endogenous antioxidants probably through phosphoinositide 3-kinase/protein kinase-B (PI3K/Akt) guided transcriptional activation of nuclear factor (erythroid-derived 2)-like 2 (Nrf2). In addition, NG inhibited IR-induced inflammation through suppression of NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells) followed by the alteration of pro inflammatory factors. Taken together, these results suggested that NG reversed the IR-induced redox-imbalance in murine liver, probably by the inhibition of ROS/p38-MAPK/NF-κB, along with the activation of the PI3K/Akt/Nrf2 pathway and the reduction of apoptosis by interfering with the p53/SAPK/JNK/Bax pathway.
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- 2016
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7. Gossypetin ameliorates ionizing radiation-induced oxidative stress in mice liver—a molecular approach
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Krishnendu Manna, Asoke Banerji, Kunal Sikder, Aaveri Sengupta, Ujjal Das, Swaraj Bandhu Kesh, Amitava Khan, Anindita Chakrabarty, Mahua Ghosh, Sushobhan Biswas, Mahuya Sinha, Dipesh Kr. Das, Sanjit Dey, and Sanjukta Datta
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Male ,NF-E2-Related Factor 2 ,Radioprotective Agent ,Drug Evaluation, Preclinical ,Biological Availability ,Radiation-Protective Agents ,Biology ,Pharmacology ,medicine.disease_cause ,Biochemistry ,Antioxidants ,Lipid peroxidation ,Mice ,Phosphatidylinositol 3-Kinases ,chemistry.chemical_compound ,medicine ,Animals ,DNA Breaks, Double-Stranded ,Aspartate Aminotransferases ,Protein kinase A ,Flavonoids ,chemistry.chemical_classification ,Reactive oxygen species ,Gossypetin ,Molecular Structure ,Interleukin-6 ,Superoxide Dismutase ,Tumor Necrosis Factor-alpha ,Alanine Transaminase ,Free Radical Scavengers ,General Medicine ,Alkaline Phosphatase ,Catalase ,Glutathione ,Comet assay ,Oxidative Stress ,Liver ,chemistry ,Gamma Rays ,Apoptosis ,Hepatocytes ,Lipid Peroxidation ,Oxidation-Reduction ,Proto-Oncogene Proteins c-akt ,Oxidative stress ,Signal Transduction - Abstract
Radioprotective action of gossypetin (GTIN) against gamma (γ)-radiation-induced oxidative stress in liver was explored in the present article. Our main aim was to evaluate the protective efficacy of GTIN against radiation-induced alteration of liver in murine system. To evaluate the effect of GTIN, it was orally administered to mice at a dose of 30 mg/kg body weight for three consecutive days prior to γ-radiation at a dose of 5 Gy. Radioprotective efficacy of GTIN were evaluated at physiological, cellular, and molecular level using biochemical analysis, comet assay, flow cytometry, histopathology, immunofluorescence, and immunoblotting techniques. Ionizing radiation was responsible for augmentation of hepatic oxidative stress in terms of lipid peroxidation and depletion of endogenous antioxidant enzymes. Immunoblotting and immunofluorescence studies showed that irradiation enhanced the nuclear translocation of nuclear factor kappa B (NF-κB) level, which leads to hepatic inflammation. To investigate further, we found that radiation induced the activation of stress-activated protein kinase/c-Jun NH2-terminal kinase (SAPK/JNK)-mediated apoptotic pathway and deactivation of the NF-E2-related factor 2 (Nrf2)-mediated redox signaling pathway, whereas GTIN pretreatment ameliorated these radiation-mediated effects. This is the novel report where GTIN rationally validated the molecular mechanism in terms of the modulation of cellular signaling system’ instead of ‘ This is the novel report where GTIN is rationally validated in molecular terms to establish it as promising radioprotective agents. This might be fruitful especially for nuclear workers and defense personnel assuming the possibility of radiation exposure.
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- 2015
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8. Naringin inhibits gamma radiation-induced oxidative DNA damage and inflammation, by modulating p53 and NF-κB signaling pathways in murine splenocytes
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Amitava Khan, Krishnendu Manna, Swaraj Bandhu Kesh, Ujjal Das, Anindita Chakraborty, Soumyajit Dey, and Dipesh Kr. Das
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Cell signaling ,Cell cycle checkpoint ,DNA damage ,p38 mitogen-activated protein kinases ,Anti-Inflammatory Agents ,Radiation-Protective Agents ,Biology ,Biochemistry ,Mice ,Downregulation and upregulation ,Animals ,Viability assay ,chemistry.chemical_classification ,Reactive oxygen species ,NF-kappa B ,General Medicine ,G1 Phase Cell Cycle Checkpoints ,Molecular biology ,chemistry ,Gamma Rays ,Flavanones ,Tumor Suppressor Protein p53 ,Spleen ,Intracellular ,DNA Damage ,Signal Transduction - Abstract
The adverse effects of ionizing radiation occur due to the generation of reactive oxygen species (ROS). The aim of this study was to identify the protective effects of naringin (NG), a citrus flavonoid, on ionizing radiation (IR)-induced differential stress response, with an exploration of the mechanisms involved in this process. Isolated murine splenocytes were incubated in the presence and in the absence of different concentrations of NG (50 and 100 μM) for 1 h prior to 6 Gy γ-irradiation, and the molecular mechanisms of action were determined through biochemical, immunoblot, flow cytometric, and immunofluorescence studies. Pretreatment with NG significantly prevented IR-induced intracellular ROS generation, thereby preventing the formation of cellular TBARS and the development of cellular nitrite. NG significantly reduced nuclear DNA damage with respect to the irradiated splenocytes, through the inhibition of DNA-PKcs and p-γH2AX. The reduced cell viability as a result of irradiation was recovered by NG through modulation of the redox-regulated cell signaling system. NG pretreatment resulted in significant inhibition of IR-induced G1/S phase cell cycle arrest through the modulation of p53-dependent p21/WAF1, cyclin E, and CDK2 activation. The results also demonstrated that NG blocked the IR-induced p38 function and reversed IR-mediated differential stress response through inhibition of the NF-κB pathway. Thus, the p38/NF-κB pathway participated in the IR-induced inflammatory development, leading to upregulation of CRP, MCP-1, and iNOS2 gene expression. However, NG pretreatment reversed the inflammatory development through downregulation of NF-κB, and regulated the expression of CRP, MCP-1, and iNOS2. The above results provide a theoretical basis for the preventive use of NG against radiation-induced multiple cellular anomalies.
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- 2015
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9. Gossypetin, a naturally occurring hexahydroxy flavone, ameliorates gamma radiation-mediated DNA damage
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Chinchu Bose, Krishnendu Manna, Sanjit Dey, Asoke Banerji, Amitava Khan, Mahuya Sinha, Dipesh Kr. Das, Anindita Chakrabarty, and Swaraj Bandhu Kesh
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Male ,Metal chelating activity ,DNA damage ,Radical ,Intracellular Space ,Radiation-Protective Agents ,Iron Chelating Agents ,Nitric Oxide ,Mice ,chemistry.chemical_compound ,Picrates ,Animals ,Radiology, Nuclear Medicine and imaging ,Flavonoids ,chemistry.chemical_classification ,Biological Products ,Reactive oxygen species ,Gossypetin ,Radiological and Ultrasound Technology ,DNA, Superhelical ,Hydroxyl Radical ,Chemistry ,Biphenyl Compounds ,Free Radical Scavengers ,Free radical scavenger ,Comet assay ,Biochemistry ,Gamma Rays ,Hydroxyl radical ,Reactive Oxygen Species ,Oxidation-Reduction ,DNA Damage - Abstract
To evaluate the protective effect of gossypetin (GTIN) against gamma (γ)-radiation-mediated DNA damage.Increasing concentrations (10-150 μM) of GTIN were incubated with supercoiled DNA 1 h prior exposure to γ-radiation in the range of 5-Gy absorbed dose from Co(60) γ source. To establish the effective protective concentration of GTIN, supercoiled DNA was pre-incubated with 50 μM of GTIN for 1 h followed by exposure of 5, 10 and 20 Gy doses of γ-radiation. Moreover, 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical, hydroxyl radical, nitric oxide (NO) scavenging, metal chelating activity and ferric reducing antioxidant power (FRAP) of GTIN were measured and compared with standards. The flowcytometric analysis and radiation-induced genomic DNA damage by comet assay were employed to estimate the level of intracellular reactive oxygen species (ROS) using isolated murine hepatocytes.GTIN was able to effectively scavenge different free radicals in in vitro situations. It could significantly prevent radiation induced supercoiled and genomic DNA damage with reduced comet parameters. It also acted as a potent scavenger of the radiation induced ROS.GTIN ameliorated radiation-induced oxidative stress and DNA damage by its free-radical scavenging activity.
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- 2013
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10. Radiation Protection by Major Tea Polyphenol, Epicatechin
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Sanjit Dey, Kankana Das, Krishnendu Manna, Dipesh Kr. Das, Amitava Khan, and Mahuya Sinha
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medicine.medical_specialty ,biology ,Chemistry ,business.industry ,Acid phosphatase ,Glutathione ,medicine.disease_cause ,Lipid peroxidation ,chemistry.chemical_compound ,Endocrinology ,Polyphenol ,Internal medicine ,Genetics ,medicine ,biology.protein ,Alkaline phosphatase ,Liver function ,Radiation protection ,business ,Genetics (clinical) ,Oxidative stress - Abstract
Whole body radiation exposure causes extensive physiological stress which may prove fatal if it is not appropriately managed. The current study is intended to evaluate the radioprotective effects of epicatechin (EC) in terms of amelioration of radiation induced hepatic and testicular oxidative stress. Swiss albino mice were administered with EC for three consecutive days before exposing them to a single dose of 5-Gy 60 Co gamma (γ) irradiation. Mice were necropsied and liver and testis were taken for biochemical tests for the detection of hepatic and testicular oxidative stress markers. To determine the oxidative stress developed after radiation SGOT, SGPT and ALP were measured to assess the alterations in liver function, reduced glutathione (GSH) content and lipid peroxidation (LPO) were also determined from liver homogenate. To evaluate oxidative stress of testis, LPO, Alkaline Phosphatase (ALP) and Acid Phosphatase (ACP) were also evaluated. Whole body gamma radiation enhanced SGOT, SGPT and ALP level increased as also LPO and depleted GSH level in liver homogenate. Testicular damage was prominent since LPO and ACP level enhanced where as ALP level decreased. Epicatechin pretreatment ameliorated all these gamma radiation mediated alterations and improved the mice from the situation of oxidative stress. Thus, epicatechin pretreatment ameliorated radiation mediated systemic oxidative stress which also prevented liver and testis from further damage.
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- 2013
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11. Smokeless tobacco consumption impedes metabolic, cellular, apoptotic and systemic stress pattern: A study on Government employees in Kolkata, India
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Surajit Bose, Anirban Pradhan, Amitava Khan, Sushobhan Biswas, Ujjal Das, Krishnendu Manna, Aaveri Sengupta, Saurabh Ghosh, and Sanjit Dey
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0301 basic medicine ,Adult ,Cyclin-Dependent Kinase Inhibitor p21 ,Male ,Pathology ,medicine.medical_specialty ,Erythrocytes ,Tobacco, Smokeless ,genetic structures ,India ,Nitric Oxide Synthase Type II ,Apoptosis ,Peripheral blood mononuclear cell ,Article ,03 medical and health sciences ,0302 clinical medicine ,Bcl-2-associated X protein ,Stress, Physiological ,TBARS ,Medicine ,Humans ,Interleukin 6 ,bcl-2-Associated X Protein ,Multidisciplinary ,biology ,business.industry ,Interleukin-6 ,Tumor Necrosis Factor-alpha ,Lipids ,030104 developmental biology ,Smokeless tobacco ,Proto-Oncogene Proteins c-bcl-2 ,Cyclooxygenase 2 ,030220 oncology & carcinogenesis ,Immunology ,Absolute neutrophil count ,biology.protein ,Leukocytes, Mononuclear ,Tumor necrosis factor alpha ,Female ,Tumor Suppressor Protein p53 ,business - Abstract
Smokeless tobacco (SLT) remains a threat amongst a large population across the globe and particularly in India. The oral use of tobacco has been implicated to cause physiological stress leading to extreme toxicological challenge. The study included 47 SLT-users and 44 non-users providing a spectrum of pathophysiological, clinico-biochemical, antioxidant parameters, cell cycle progression study of PBMC and morphological changes of red blood cells (RBC). The expressions of p53, p21, Bax, Bcl-2, IL-6, TNF- α, Cox-2, iNOS were analyzed from thirteen representative SLT-users and twelve non-users. Difference in CRP, random glucose, serum cholesterol, TG, HLDL-C, LDL-C, VLDL-C, neutrophil count, monocyte count, ESR, SOD (PBMC) and TBARS (RBC membrane) were found to be statistically significant (p
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- 2015
12. Dinuclear zinc(II) complexes with compartmental ligands: syntheses, structures, and bioactivities as artificial nuclease
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Sudhanshu Das, Sanjit Dey, Ennio Zangrando, Pali Maiti, Dipayan Bose, Tanmay Chattopadhyay, Debasis Das, Amitava Khan, Krishnendu Manna, Pali, Maiti, Amitava, Khan, Tanmay, Chattopadhyay, Sudhanshu, Da, Krishnendu, Manna, Dipayan, Bose, Sanjit, Dey, Zangrando, Ennio, and Debasis, Das
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Nuclease ,Coordination sphere ,[compartmental ligands] ,biology ,zinc(II) complex ,Stereochemistry ,Ligand ,Metal ions in aqueous solution ,chemistry.chemical_element ,Zinc ,Metal ,Trigonal bipyramidal molecular geometry ,chemistry ,visual_art ,Materials Chemistry ,visual_art.visual_art_medium ,biology.protein ,compartmental ligands ,Chelation ,Physical and Theoretical Chemistry - Abstract
Four water-soluble dinuclear Zn(II) complexes (1–4) of compartmental ligand L = 2,6-bis(R-iminomethyl)-4-R′-phenolate (where R = N-ethylpiperidine or R = N-ethylpyrrolidine, R′ = methyl or tert-butyl) have been synthesized, characterized, and their DNA cleavage activity and cytotoxicity toward HepG2 cancerous cells are evaluated. The dinuclear complexes are formed by a pentadentate-substituted phenolate ligand chelating the metal ions separated by ca 3.27 A. Each metal is a distorted trigonal bipyramid, completing the coordination sphere through acetate. The X-ray structural determination of 2 shows that the complex is counterbalanced by half (formulation [Zn2L2(CH3CO2)2][(Zn(SCN)4]0.5), while in 1 and 3 two crystallographically-independent complexes are present in the unit cell with a . Among the four complexes only the 4-tert-butyl-phenolato derivatives (3 and 4) show DNA cleavage activity in in-vivo conditions and appear to be promising toward metal complexes to be used as anticancer agents. The cytoto...
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- 2011
13. Phytochemicals Safeguard the Genome: Tiny Molecules, Big Role
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Sanjit Dey, Nilanjan Das, Debdutta Ganguli, Mahuya Sinha, Kunal Sikder, Swaraj Bandhu Kesh, Dipesh Kr Das, Amitava Khan, Ujjal Das, Krishnendu Manna, Sushobhan Biswas, Anirban Pradhan, and Rakhi Sharma Dey
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- 2015
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14. Seabuckthron (Hippophae rhamnoides L.) leaf extract ameliorates the gamma radiation mediated DNA damage and hepatic alterations
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Amitava, Khan, Krishnendu, Manna, Chinchubose, Dipesh Kr, Das, Mahuya, Sinha, Swaraj Bandhu, Kesh, Ujjal, Das, Rakhi Sharma, Dey, Asoke, Banerji, and Sanjit, Dey
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Male ,Plant Leaves ,Mice ,Liver ,DNA, Superhelical ,Gamma Rays ,Plant Extracts ,Hippophae ,Animals ,Free Radical Scavengers ,DNA Damage - Abstract
In vitro assessment showed that H. rhamnoides (HrLE) extract possessed free radical scavenging activities and can protect gamma (gamma) radiation induced supercoiled DNA damage. For in vivo study, Swiss albino mice were administered with HrLE (30 mg/kg body weight) for 15 consecutive days before exposing them to a single dose of 5 Gy of beta radiation. HrLE significantly prevented the radiation induced genomic DNA damage indicated as a significant reduction in the comet parameters. The lipid peroxidation, liver function enzymes, expression of phosphorylated NFkappaB (p65) and IkappaBalpha increased whereas the endogenous antioxidants diminished upon radiation exposure compared to control. Pretreatment of HrLE extract ameliorated these changes. Based on the present results it can be concluded that H. rhamnoides possess a potential preventive element in planned and accidental nuclear exposures.
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- 2014
15. Role of ligand backbone of tridentate Schiff-base on complex nuclearity and bio-relevant catalytic activities of zinc(II) complexes: Experimental and theoretical investigations
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Debasis Das, Amitava Khan, Prateeti Chakraborty, Ennio Zangrando, Sanjit Dey, Krishnendu Manna, Antonio Bauzá, Ria Sanyal, Jaydeep Adhikary, Antonio Frontera, Chakraborty, Prateeti, Adhikary, Jaydeep, Sanyal, Ria, Khan, Amitava, Manna, Krishnendu, Dey, Sanjit, Zangrando, Ennio, Bauzá, Antonio, Frontera, Antonio, and Das, Debasis
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Materials Chemistry2506 Metals and Alloys ,Schiff base ,Ligand ,Stereochemistry ,Mononuclear zinc ,chemistry.chemical_element ,Trinuclear zinc ,Zinc ,Cleavage (embryo) ,Catalysis ,Inorganic Chemistry ,chemistry.chemical_compound ,chemistry ,Morpholine ,DFT study ,DNA cleavage activity ,Phosphatase activity ,Physical and Theoretical Chemistry ,Phosphodiester bond ,Materials Chemistry ,Hydroxyl radical - Abstract
Reaction of ZnII-acetate with two N, N, O-donor Schiff-base ligands, HL1 {4-Chloro-2-[(2-morpholin-4-yl-ethylimino)-methyl]-phenol} and HL2 {4-Chloro-2-[(3-morpholin-4-yl-propylimino)-methyl]-phenol}, which are formed in situ via condensation of 5-chlorosalicylaldehyde and N-(2-aminoethyl/propyl)morpholine, produce one tri- and one mononuclear species, Zn3L1(OAc)4 (1) and ZnL2(OAc) (2). The hypothetical ZnL1(OAc) and Zn3L2(OAc)4 are energetically unfavorable by 9.2 and 5.1 kcal/mol, in compare with their respective real counterparts 1 and 2 evidenced from DFT calculations. Both 1 and 2 catalyze the hydrolytic cleavage of phosphoester bond of (4-nitrophenyl) phosphate where 1 shows higher activity than that of 2. The proposed mechanistic pathways of phosphatase activity of 1 and 2 and the higher efficiency of the latter have been rationalized by DFT study. DNA cleavage activities have been investigated using supercoiled pET28a plasmid DNA where both the complexes show dose dependent DNA cleavage activity with varying degree. Complex 1 shows excellent breakage activity even at a concentration of 20 μM. However, in both cases hydroxyl radical pathway is most probably operative in DNA cleavage activity.
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- 2014
16. Protective effect of coconut water concentrate and its active component shikimic acid against hydroperoxide mediated oxidative stress through suppression of NF-κB and activation of Nrf2 pathway
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Sreya Chattopadhyay, Sayan Ghosh, Ujjal Das, Amitava Khan, Debprasad Chattopadhyay, Krishnendu Manna, Swaraj Bandhu Kesh, Krishna Das Saha, Anindita Chakraborty, Rakhi Sharma Dey, Dipesh Kr. Das, and Sanjit Dey
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Cocos ,Programmed cell death ,NF-E2-Related Factor 2 ,Apoptosis ,Shikimic Acid ,Biology ,medicine.disease_cause ,Antioxidants ,chemistry.chemical_compound ,Mice ,Drug Discovery ,medicine ,Animals ,Protein kinase B ,PI3K/AKT/mTOR pathway ,Pharmacology ,Dose-Response Relationship, Drug ,NF-kappa B ,Glutathione ,Hydrogen Peroxide ,Flow Cytometry ,Oxidative Stress ,Biochemistry ,chemistry ,Hepatocytes ,Liver function ,Intracellular ,Oxidative stress ,DNA Damage ,Signal Transduction - Abstract
Ethnopharmacological relevance Conventionally coconut water has been used as an ‘excellent hydrating’ drink that maintain the electrolyte balance and help in treating diverse ailments related to oxidative stress including liver function. The present study was aimed to elucidate whether and how the coconut water concentrate (CWC) and its major active phytoconstituent shikimic acid (SA) can effectively protect murine hepatocytes from the deleterious effect of hydroperoxide-mediated oxidative stress. Materials and methods Bioactivity guided fractionation of CWC resulted in the isolation of a couple of known compounds. Freshly isolated murine hepatocytes were exposed to hydrogen peroxide (H 2 O 2 ) (1 and 3 mM) in the presence or absence of CWC (200 and 400 μg/ml) and SA (40 μM) for the determination of antioxidative, DNA protective, cellular ROS level by modern methods, including immunoblot and flowcytometry to find out the possible mechanism of action. Results Pre-treatment of hepatocyte with CWC and SA showed significant prevention of H 2 O 2 -induced intracellular ROS generation, nuclear DNA damage along with the formation of hepatic TBARS and cellular nitrite. Further, the H 2 O 2 induced cell death was arrested in the presence of CWC through the inhibition of CDC42 mediated SAPK/JNK pathways and activation of other molecules of apoptotic pathways, including Bax and caspase3. Moreover, CWC and SA help in maintaining the GSH level and endogenous antioxidants like Mn-SOD, to support intracellular defense mechanisms, probably through the transcriptional activation of Nrf2; and inhibition of nuclear translocation of NF-κB. Conclusion CWC and its active components SA reversed the H 2 O 2 induced oxidative damage in hepatocytes, probably through the inhibition of NF-κB, with the activation of PI3K/Akt/Nrf2 pathway and reduction of apoptosis by interfering the SAPK/JNK/Bax pathway.
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- 2013
17. Dinuclear cobalt(II) complexes of Schiff-base compartmental ligands: Syntheses, crystal structure and bio-relevant catalytic activities
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Jaydeep Adhikary, Amitava Khan, Ennio Zangrando, Krishnendu Manna, Arpita Banerjee, Debasis Das, Averi Guha, Sanjit Dey, Banerjee, Arpita, Guha, Averi, Adhikary, Jaydeep, Khan, Amitava, Manna, Krishnendu, Dey, Sanjit, Zangrando, Ennio, and Das, Debasis
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DNA cleavage ,Schiff base ,Stereochemistry ,Cobalt(II) complexes ,Cytotoxicity ,Substrate (chemistry) ,chemistry.chemical_element ,Crystal structure ,Catalysis ,Inorganic Chemistry ,chemistry.chemical_compound ,chemistry ,Cobalt(II) complexes, DNA cleavage, Cytotoxicity, Catechol oxidase ,Catechol oxidase ,Materials Chemistry ,MTT assay ,Physical and Theoretical Chemistry ,Single crystal ,Cobalt ,DNA - Abstract
Three dicobalt(II) complexes, namely [Co2(L1H)(H2O)2(OAc)2](OAc)2 (1), [Co2(L2)(H2O)2(OAc)2](OAc) (2) and [Co2(L3)(H2O)2(OAc)2](OAc) (3) of the p-cresol based “end-off” compartmental ligands 2,6-bis(R-iminomethyl)-4-methyl-phenolato, where R = N-ethylpiperazine for L1, 2-ethylpyridine for L2 and N-ethylpiperidine for L3, have been synthesized and characterized by common physicochemical techniques, and in the case of complex 1 also by single crystal X-ray diffraction analysis. All the complexes show excellent catecholase-like activity, monitored not only with 3,5-di-tert-butylcatechol but also with tetrachlorocatechol, a substrate reluctant to be oxidized. To the best of our knowledge, to date no cobalt complex has been found in the literature to manifest such activity. The complexes are observed to interact efficiently with CT-DNA and on incubation (employing plasmid pTZ57/R/T DNA) they exhibit concentration dependent DNA cleavage activity. The mechanisms related to the DNA cleavage and catecholase-like activities have been investigated. The cytotoxicity of the complexes has also been examined through an MTT assay.
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- 2013
18. Promising role of ferulic acid, atorvastatin and their combination in ameliorating high fat diet-induced stress in mice
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Krishnendu Manna, Dipesh Kr. Das, Sanjit Dey, Kunal Sikder, Amitava Khan, Nilanjan Das, and Swaraj Bandhu Kesh
- Subjects
Male ,medicine.medical_specialty ,Antioxidant ,Normal diet ,Coumaric Acids ,medicine.medical_treatment ,Atorvastatin ,Hyperlipidemias ,medicine.disease_cause ,Diet, High-Fat ,Weight Gain ,General Biochemistry, Genetics and Molecular Biology ,Antioxidants ,Ferulic acid ,Lipid peroxidation ,chemistry.chemical_compound ,Mice ,Internal medicine ,Hyperlipidemia ,medicine ,Animals ,Pyrroles ,General Pharmacology, Toxicology and Pharmaceutics ,chemistry.chemical_classification ,Inflammation ,Reactive oxygen species ,Interleukin-6 ,Tumor Necrosis Factor-alpha ,NF-kappa B ,General Medicine ,Free Radical Scavengers ,medicine.disease ,Oxidative Stress ,Endocrinology ,chemistry ,Liver ,Heptanoic Acids ,Hepatocytes ,Drug Therapy, Combination ,Lipid Peroxidation ,Hydroxymethylglutaryl-CoA Reductase Inhibitors ,Reactive Oxygen Species ,Oxidative stress ,medicine.drug ,Signal Transduction - Abstract
Aims The present study evaluated a comparative and combined hepatoprotective effect of atorvastatin (AS) and ferulic acid (F) against high fat diet (HFD) induced oxidative stress in terms of hyperlipidemia, anti-oxidative status, lipid peroxidation and inflammation. Main methods Male Swiss albino mice were given a diet containing high fat (H) (23.9% wt/wt), supplemented with AS (10 mg/kg) or F (100 mg/kg) and both (10 and 100 mg/kg) for 8 weeks. The control mice (C) were fed with normal diet. Key findings The H mice exhibited increased body weight; hyperlipidemia; serum level of tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6); hepatic lipid profile; lipid accumulation; reactive oxygen species (ROS) of hepatocytes, lipid peroxidation and liver antioxidant capacity was decreased. Immunofluorescent and Western blot assay revealed activation of nuclear factor kappa B (NF-κB) signaling pathway. The addition of F or AS and both in the diet significantly counteracted HFD induced body weight gain; hyperlipidemia; TNF-α, IL-6; hepatic lipid profile; fatty infiltration; NF-κB signaling pathway; ROS; lipid peroxidation and moreover elevated levels of hepatic antioxidant enzymes activity were observed. Significance Simultaneous treatment with AS, F and their combination protected against HFD induced weight gain and oxidative stress. The protection may be attributed to the hypolipidemic and free radical scavenging activity of AS or F and their combination. This study illustrates that AS and F have relatively similar hypolipidemic, antioxidative, anti-inflammatory actions and the AS + F combination along with HFD has shown outstanding effects as compared to other treated groups.
- Published
- 2012
19. Gossypetin ameliorates ionizing radiation-induced oxidative stress in mice liver—a molecular approach
- Author
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Amitava Khan, Krishnendu Manna, Dipesh Kr Das, Swaraj Bandhu Kesh, Mahuya Sinha, Ujjal Das, Sushobhan Biswas, Aaveri Sengupta, Kunal Sikder, Sanjukta Datta, Mahua Ghosh, Anindita Chakrabarty, Asoke Banerji, Sanjit Dey, Amitava Khan, Krishnendu Manna, Dipesh Kr Das, Swaraj Bandhu Kesh, Mahuya Sinha, Ujjal Das, Sushobhan Biswas, Aaveri Sengupta, Kunal Sikder, Sanjukta Datta, Mahua Ghosh, Anindita Chakrabarty, Asoke Banerji, and Sanjit Dey
- Published
- 2015
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