A. Rama Narsimha Reddy

Kakatiya University, Warangal, Andhra Pradesh, India

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Publications (20)19.82 Total impact

  • A. Rama Narsimha Reddy, D.R. Krishna, V. Himabindu, Y. Narsimha Reddy
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    ABSTRACT: The aim of the present study was to evaluate the potential toxicity and general mechanisms involved in single walled carbon nanotubes (SWCNTs)-induced cytotoxicity using human embryonic kidney cell line (HEK293) cells. Carbon nanotubes (coded as CNT) used in this study were synthesized by the chemical vapor deposition method. To elucidate the possible mechanisms underlying SWCNT-induced cytotoxicity, cell viability, cell membrane damage (lactate dehydrogenase activity (LDH) assay), reduced glutathione (GSH), interleukin-8 (IL-8) and lipid peroxidation products levels were quantitatively assessed following SWCNT exposure for 48 hr using HEK293 cells. Exposure of cells to SWCNT at 3–300 μg/ml produced significant reduction in cell viability in a concentration-dependent manner. The IC50 value of SWCNT was found to be 87.58 μg/ml. Exposure of HEK cells to SWCNT at 10–100 μg/ml resulted in concentration-dependent cell membrane damage, increased production of IL-8, elevated levels of thiobarbituric acid reactive substances like malondialdehyde and decreased intracellular GSH levels. In summary, exposure to SWCNT resulted in a concentration-dependent cytotoxicity in cultured HEK293 cells that was associated with increased oxidative stress.
    Toxicological and Environmental Chemistry 07/2014; 96(6). DOI:10.1080/02772248.2014.993112 · 0.72 Impact Factor
  • P Maheshwari, B Baburao, Ch Pradeep Kumar, A Rama Narsimha Reddy
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    ABSTRACT: Diabetes mellitus is a metabolic disorder characterized by hyperglycemia and its occurrence is increasing fast in most of the countries. Herbal medicine derived from plant extracts have been utilized increasingly for the treatment of various disorders like diabetes mellitus. The present study was designed to evaluate the antidiabetic activity of Methanolic Extract of Hiptage bengalensis L. Kurz (MEHB) in alloxan induced diabetic rats and chick model. Alloxan (120 mg kg-1) was used to induce diabetes in rats and the blood glucose levels were estimated by using commercial kit in the market. The methanolic extract of Hiptage bengalensis was administered to diabetic rats as single dose for one day at a dose of 100 and 200 mg kg-1. The extract produced a significant reduction (p<0.01) of blood glucose levels at a dose of 100 and 200 mg kg-1 in diabetic rats. It also showed a beneficial effect on the lipid profile in alloxan induced diabetic rats. These results showed that methanolic extract of Hiptage bengalensis produced a dose dependant antihyperglycemic activity in rats.
    Pakistan Journal of Biological Sciences 09/2013; 16(17):844-51. DOI:10.3923/pjbs.2013.844.851
  • Gangarapu Kiran, Manda Sarangapani, Thumma Gouthami, Anreddy Rama Narsimha Reddy
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    ABSTRACT: In the present study, the synthesis of new bis-isatin carbohydrazone derivatives and their antimicrobial and antioxidant activities were investigated. The structures of new compounds were elucidated by Fourier transform infrared, 1H nuclear magnetic resonance and mass spectra. The antimicrobial activity of the compounds was determined by using the two-fold serial dilution technique against various bacterial and fungal species in comparison to standard drugs. All synthesized compounds displayed a broad spectrum of activities with minimum inhibitory concentration values ranging from 6.25 to 100 μg/ml against tested microorganisms. The in vitro antioxidant activity was evaluated using 1,1-diphenyl-2-picryl-hydrazyl and hydrogen peroxide (H2O2), and the total antioxidant capacity by a phosphomolybdenum assay and their ability to chelate ferrous iron. In general, the derivatives were found to exhibit antioxidant activity. Further, the compounds with electron-withdrawing groups at the C5 position demonstrated significant antimicrobial and antioxidant activities.
    Toxicological and Environmental Chemistry 03/2013; 95(3). DOI:10.1080/02772248.2013.777605 · 0.72 Impact Factor
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    ABSTRACT: Occupational exposure is unregulated in developing countries like India, and becoming the most common cause of disease of environmental origin. The present study was aimed to investigate the effects of occupational exposure on plasma lipid profiles, and risk of cardiovascular diseases. A total of 79 human volunteers were included in the study. Control subjects were healthy housewives of Karimnagar, India. Occupationally exposed individuals included different occupational workers like petrol station attendants, battery chargers, drivers, welders, pesticide-exposed workers, painters, and auto mechanics. These subjects were shown to be chronic occupationally-exposed for at least three years, and neither associated with any other chronic pathological conditions like hypertension or diabetes, nor under any medication other than analgesics during the month preceding the study. Subjects with excessive high or low caloric intake were excluded from the study. Total cholesterol (TC), LDL cholesterol, triglycerides (TG), VLDL cholesterol, LDL/HDL cholesterol, and TC/HDL ratio in these subjects were significantly higher than those in control subjects, whereas HDL cholesterol was not markedly affected. Blood pressure (systolic and diastolic), and other anthropometric parameters (body mass index (BMI), body fat index (BFI), body surface area (BSA)) were not significantly different between groups. Data suggest that chronic occupational exposure increases plasma lipid levels and is thereby associated with cardiovascular complications.
    Toxicological and Environmental Chemistry 02/2013; 95(2). DOI:10.1080/02772248.2013.769322 · 0.72 Impact Factor
  • Ch. Tejasree, G. Kiran, G. Rajyalakshmi, A. Rama Narsimha Reddy
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    ABSTRACT: The aim of the present study was to evaluate the hepatoprotective activity of 1-(4-(dimethylamino)benzylidene)-5-(2-oxoindolin-3-ylidene) thiocarbohydrazone, a novel isatin derivative against carbon tetrachloride (CCl4)-induced hepatotoxicity in rats. Hepatic damage was induced by administration of CCl4 (1 ml/kg, b.w., p.o.) in combination with liquid paraffin (1:1) as a single dose. The hepatotoxic rats were treated with test compound at doses of 50 or 100 mg/kg for three days and liver damage biomarkers, including activities of serum glutamate pyruvate transaminase (SGPT), serum glutamate oxaloacetate transaminase (SGOT), serum alkaline phosphatase (ALP), and levels of total serum bilirubin (TB) measured in blood samples. Results demonstrated that treatment with test compound at doses of 50 or 100 mg/kg to hepatotoxic rats produced a significant dose-dependent reduction of elevated SGOT, SGPT, ALP activities and TB levels indicating a hepatoprotective effect that was confirmed by histopathological examination of liver tissues. The study results confirmed the hepatoprotective activity of 1-(4-(dimethylamino)benzylidene)-5-(2-oxoindolin-3-ylidene) thiocarbohydrazone in rats.
    Toxicological and Environmental Chemistry 01/2013; 95(9). DOI:10.1080/02772248.2014.887257 · 0.72 Impact Factor
  • A. Rama Narsimha Reddy, J. Nagaraju, G. Rajyalaksmi, M. Sarangapani
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    ABSTRACT: The present study was aimed to evaluate the cardioprotective activity of N-(benzo[d]oxazol-2-yl)-2-(5-bromo-2-oxoindolin-3-ylidene)hydrazinecarboxamide (coded as ARL) in rats. Doxorubicin (DOX) (15 mg kg−1, i.p, single dose) was used to induce cardiotoxicity in rats. Four groups of female Wistar albino rats were used. Group 1 was used as control (0.5% CMC, oral); the other groups were treated with DOX (single i.p. dosage of 15 mg kg−1) or DOX plus compound ARL (50 or 100 mg kg−1 day−1, p.o.), respectively. Animals were treated with ARL or CMC for 7 days. On 6th day, a single dose of DOX was administered to rats. Blood was collected on 7th day. Evaluation of cardioprotective activity was estimated using biochemical parameters including plasma aspartate aminotransferase, creatine kinase (CK-MB), lactate dehydrogenase (LDH), and triglycerides (TG) levels. Pretreatment with compound ARL significantly reduced the elevated levels of cardiotoxic biomarkers in plasma. DOX-induced depletion of glutathione levels in blood was significantly alleviated by pretreatment with compound ARL.
    Toxicological and Environmental Chemistry 12/2012; 94(10). DOI:10.1080/02772248.2012.741335 · 0.72 Impact Factor
  • G. Rajyalakshmi, A. Rama Narsimha Reddy, M. Sarangapani
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    ABSTRACT: A new series of 5- or 7-substituted 3-{4-(5-mercapto-1,3,4-oxadiazol-2-yl)phenylimino}-indolin-2-one derivatives were screened for In vitro antioxidant and antimicrobial activities. The results of this study revealed that all synthesized compounds were significantly scavenged DPPH free radicals in a concentration-dependant manner. The IC50 values of all test compounds were found to be between 18.34 and 50.54 µM. All compounds significantly inhibited growth of bacteria and most of the minimum inhibitory concentration values were between 20 and 100 mg mL−1 indicating potent to moderate antibacterial activity. In conclusion, 3-{4-(5-mercapto-1,3,4-oxadiazole-2-yl)phenylimino)-5 or 7-substituted indolin-2-ones derivatives exhibited moderate antioxidant and antimicrobial activities.
    Toxicological and Environmental Chemistry 12/2012; 94(10). DOI:10.1080/02772248.2012.741336 · 0.72 Impact Factor
  • G Kiranmai, A. Rama Narsimha Reddy
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    ABSTRACT: In this present study, antioxidant status was evaluated in rat serum following exposure to magnesium oxide (MgO) nanoparticles. The lungs of rats were intratracheally instilled with (single dose) phosphate-buffered saline (PBS) + 1% of Tween 80 (solvent control) or MgO or carbonyl iron (negative control) or quartz particles (positive control) at a dose of 1 and 5 mg/kg of body weight. The blood samples were collected at 1, 7, and 30 days of postinstillation of nanoparticles after their exposure, and different parameters were estimated to assess the oxidative stress induced by the instillation of MgO. Exposure of rats to MgO produced a significant (p < 0.05) dose-dependent reduction in blood total antioxidant capacity, superoxide dismutase, and catalase activity levels than PBS + 1% Tween 80 control group. This reduction in the antioxidant capacity in MgO nanoparticle-exposed rats indicates the reduction in antioxidant defense mechanisms due to the instillation of MgO. These results indicate that exposure to MgO nanoparticles induces oxidative stress by reducing the total antioxidant capacity in rats. The findings suggest possible occupational health hazard in chronic exposures.
    Toxicology and Industrial Health 06/2012; 29(10). DOI:10.1177/0748233712446723 · 1.71 Impact Factor
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    ABSTRACT: In this study, we have evaluated the pulmonary toxicity of intratracheally (i.t.) instilled two multi walled carbon nanotubes (MWCNT) in rats. The lungs of rats were instilled with phosphate buffered saline + 1% of Tween 80 or MWCNT or carbonyl iron or quartz particles at a dose of 0.2, 1, and 5 mg/kg b.w. Following exposure, bronchoalveolar lavage (BAL) fluid was collected from the lungs to analyze lactate dehydrogenase (LDH), alkaline phosphatase (ALP), lipid peroxidation products (MDA; malondialdehyde), and total microprotein (MTP) levels at 24 h, one week, one month, and three months post instillation periods. The lungs of particle exposed rats were also collected at the same intervals to evaluate for histopathology. Exposures of MWCNT and quartz particles to rats produced transient dose dependant increase in BAL fluid LDH, ALP, MDA, and MTP values than control at all post exposure periods. Results of lung histopathology revealed that exposure of MWCNT produced a dose dependant focal peribronchiolar lymphoid aggregates, foamy alveolar macrophage accumulation, lymphoplasmocytic infiltration, fibrosis and diffuse alveolar damage. In conclusion, instillation of MWCNT produced a greater pulmonary toxicity in rats and was comparable with that of quartz.
    Environmental Toxicology 04/2012; 27(4):211-9. DOI:10.1002/tox.20632 · 2.56 Impact Factor
  • P Maheshwari, B Baburao, A Rama Narsimha Reddy
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    ABSTRACT: The objective of the present study was to evaluate hepatoprotective activity of methanolic extract of Hiptage bengalensis (L.) kurz (MEHB) in rats. Hepatic damage was induced by administration of carbontetrachloride(1 ml/kg, b.w, p.o.) in combination with liquid paraffin (1:1) as a single dose on 7th day. The extent of liver damage was studied by estimating biochemical parameters. Administration of MEHB (200 mg & 400 mg/kg) for 6 days before carbontetrachloride administration showed a significant reduction (p < 0.01) of serum liver damage enzymes markers-aspartate transaminase, alanine transaminase, total bilirubin and alkaline phosphatase (ALP). Histopathological changes of hepatic tissue were also evaluated in control and MEHB treated groups. Results also indicated that MEHB possessed potential antioxidant effect by increasing the levels of glutathione and also possessed free radical scavenging activities. The hepatoprotective effect of Hiptage bengalensis (L.) kurz was comparable to standard drug silymarin (50 mg/kg).
    Toxicology mechanisms and methods 03/2012; 22(6):483-7. DOI:10.3109/15376516.2012.674068 · 1.37 Impact Factor
  • A. Rama Narsimha Reddy, Y. Narsimha Reddy, V Himabindu, D. Rama Krishna
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    ABSTRACT: In this study, we investigated the mechanisms involved in multi-wall carbon particles/nanomaterials (MWCNM) induced cytotoxicity using human embryonic kidney (HEK293) cells and to assess the effect of physicochemical properties on the cytotoxicity and oxidative stress induced by the carbon nanomaterials (CNM). To elucidate the possible mechanisms of CNM-induced cytotoxicity, cell viability (3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide [MTT assay]), cell membrane damage (lactate dehydrogenase enzyme [LDH] assay), reduced glutathione (GSH), interleukin-8 (IL-8) and lipid peroxidation levels were quantitatively assessed under carbon nanomaterials exposed (48 h) conditions. Exposure of different sizes of four CNM at dosage levels between 3 and 300 μg/mL decreased cell viability in a concentration- and size-dependent manner. Exposure of CNM (10-100 μg/mL) to HEK cells resulted in size-, surface area- and concentration-dependent cell membrane damage, increased production of IL-8, increased thiobarbituric acid reactive substances (TBARS) and decreased intracellular glutathione levels. In summary, the physical properties of carbon nanoparticles may alter the CNM-induced concentration-dependent cytotoxicity and oxidative stress.
    Toxicology and Industrial Health 02/2011; 27(1):3-10. DOI:10.1177/0748233710377780 · 1.71 Impact Factor
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    A. Shyam Sunder, A. Rama Narsimha Reddy, G. Kiran, S. Thirumurugu
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    ABSTRACT: The methanolic extract of Trianthema portulacastrum (Aizoaceae) was evaluated for antihyperlipidemic and antioxidant activity in high-fat-diet–induced hyperlipidemic rats. It was found that the extract caused a significant reduction in the lipid levels in hyperlipidemic rats and was comparable with the standard anti-hyperlipidemic drug atorvastatin. It was also found that the plant extract increased the liver antioxidant enzyme (catalase, superoxide dismutase, glutathione) levels while reducing the lipid peroxide (malondialdehyde) levels.
    Journal of Herbs Spices & Medicinal Plants 11/2010; 16:193-202. DOI:10.1080/10496475.2010.511074
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    ABSTRACT: The aim of the present study was to evaluate the oxidative stress and anti-oxidant status in rat serum following intra-tracheal instillation of multi wall carbon nanotubes (MWCNT). The lungs of rats were intra-tracheally instilled with (single dose of) Phosphate-buffered saline (PBS)+1% of Tween 80 (Solvent Control) or MWCNT or carbonyl Iron (negative control) or quartz particles (positive control) at a dose of 0.2, 1 and 5 mg/kg body weight. Following exposure, the blood samples were collected at 1, 7, 30 and 90 days of post instillation of nanoparticles and different parameters were estimated to assess the oxidative stress induced by the instillation of MWCNT. Exposure of MWCNT to rats produced a significant (p<0.05) dose dependent reduction of blood total anti-oxidant capacity, glutathione, superoxide dismutase, catalase activity and increased lipid peroxidation product, (Malondialdehyde) levels than PBS+1% Tween 80 control group. This reduction in the total anti-oxidant capacity in nanotubes exposed rats indicates the reduction in anti-oxidant deference mechanisms due to the instillation of MWCNT. These results indicate that, exposure of multi wall carbon nanotubes induces oxidative stress by reducing the total anti-oxidant capacity in rats. The findings suggest possible occupational health hazard in chronic exposures.
    Regulatory Toxicology and Pharmacology 10/2010; 59(2):251-7. DOI:10.1016/j.yrtph.2010.10.007 · 2.14 Impact Factor
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    ABSTRACT: The aim of this study was to evaluate the in vitro toxicity of two multi-wall carbon nanotubes on four different cell lines: human alveolar epithelial (A549) cells, hepatocytes (Hep 3B cells), human embryonic kidney cells, and intestinal (P407 cells) cells. The adverse effects of carbon nanoparticles were analyzed after 24 h incubation with different cell lines using the trypan blue dye exclusion method. Incubation of carbon nanotubes with different cells produced a concentration-dependent inhibition of growth of the cells. The TC50 or IC50 values (toxic concentration 50, i.e., concentration of particles inducing 50% cell mortality) of two nanoparticles were (1) found to be in the range 23.5–30.5 µg mL−1, and (2) less than that of quartz (known toxic agent, 28.8–66.9 µg mL−1), indicating the greater cytotoxic effect of carbon nanoparticles than quartz particles.
    Toxicological and Environmental Chemistry 10/2010; 92(9):1697-1703. DOI:10.1080/02772241003682962 · 0.72 Impact Factor
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    ABSTRACT: This study evaluated the ability of the multi wall carbon nanotubes (MWCNT) to induce extra pulmonary toxicities in rats following intra-tracheal (IT) instillation of two MWCNT. Two carbon nanoparticles were instilled into the lungs of rats (0.2, 1, and 5 mg/kg b.w.) and at different post-exposure intervals, blood and organs like liver, kidney, etc. were collected. The histopathological examination of liver tissues revealed a dose-dependent periportal lymphocytic infiltration, ballooning, foamy degeneration, and necrosis at all post-instillation periods. However, examination of kidney revealed the tubular necrosis and interstitial nephritis with 5 mg/kg dose at 1 month of post-instillation of both MWCNT. These liver and kidney toxicities were further confirmed by the elevated levels of respective tissue damage biomarkers. These results suggest the extra pulmonary toxicities of these carbon nanoparticles might be due to the translocation into the liver and kidney.
    Toxicology mechanisms and methods 06/2010; 20(5):267-72. DOI:10.3109/15376516.2010.484077 · 1.37 Impact Factor
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    ABSTRACT: The present study was aimed at evaluating the potential toxicity and the general mechanism involved in multi wall carbon nanotubes (MWCNT)-induced cytotoxicity using human embryonic kidney cell line (HEK293) cells. Two multi wall carbon nanotubes (coded as MWCNT1, size: 90-150nm and MWCNT2, size: 60-80nm) used in this study are MWCNT1 (produced by the electric arc method and size of the nanotubes was 90-150nm) and MWCNT2 (produced by the chemical vapor deposition method with size of 60-80nm). To elucidate the possible mechanisms of MWCNT induced cytotoxicity, cell viability, mitochondrial function (MTT assay), cell membrane damage (LDH assay), reduced glutathione (GSH), interleukin-8 (IL-8) and lipid peroxidation levels were quantitatively assessed under carbon nanotubes exposed (48h) conditions. Exposure of different sizes of two carbon nanotubes at dosage levels between 3 and 300mug/ml decreased cell viability in a concentration dependent manner. The IC(50) values (concentration of nanoparticles to induce 50% cell mortality) of two (MWCNT1, MWCNT2) nanoparticles were found as 42.10 and 36.95mug/ml. Exposure of MWCNT (10-100mug/ml) to HEK cells resulted in concentration dependent cell membrane damage (as indicated by the increased levels of LDH), increased production of IL-8, increased TBARS and decreased intracellular glutathione levels. The cytotoxicity and oxidative stress was significantly more in MWCNT2 exposed cells than MWCNT1. In summary, exposure of carbon nanotubes resulted in a concentration dependent cytotoxicity in cultured HEK293 cells that was associated with increased oxidative stress.
    Toxicology 04/2010; 272(1-3):11-6. DOI:10.1016/j.tox.2010.03.017 · 3.75 Impact Factor
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    ABSTRACT: The aim of the present study was to evaluate the anti hyperglycemic activity of methanolic extract of leaves of Salacia fruticosa (Family:Hippocrataceae) in alloxan induced diabetic rats. The hyperglycemic rats were divided into different groups and were treated with methanolic extract of S. fruticosa at a dose of 125 & 250mg/kg. Treatment with extract produced a significant dose dependent reduction in blood glucose levels and this anti hyperglycemic activity was comparable with the reference standard, metformin. The results of the present study revealed the anti-diabetic activity of methanolic extract of leaves of Salacia fruticosa in alloxan induced diabetic rats.
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    ABSTRACT: The present study was aimed at evaluating the In vitro free radical scavenging activity of some new isatin-5-sulphonamide derivatives using DPPH and H 2 O 2 methods. The free radical scavenging activity of test compounds was determined by DPPH, H 2 O 2 and nitric oxide radical scavenging methods. All the five test compounds showed dose dependent scavenging activity.
    Pharmacologyonline 01/2009; 1:540-545. · 0.16 Impact Factor
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    ABSTRACT: The present study was aimed at evaluating the anticonvulsant activity of some new isatin-5-sulphonamide derivativesagainst maximum electric shock induced and Pentylenetetrazol (PTZ) induced seizures in mice using phenytoin as astandard. All the five test compounds were effectiveagainst electric shock and PTZ induced convulsions at a dose of 100mg/kg. The anticonvulsant activities of test compounds were comparable with standard anticonvulsant , Phenytoin.
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    ABSTRACT: The present study was aimed at investigating the effect of nifedipine (N) on the pharmacodynamics of simvastatin (S) in hyperlipidemic rats. The standard cholesterol diet was used to induce hyperlipidemia in Wister rats. The blood samples were collected from simvastatin treated and simvastatin plus nifedipine treated rats and analyzed for pharmacodynamics (lipid profiles) of simvastatin using reported methods. The combination therapy produced a significant change in lipid profiles which were comparable with simvastatin alone.The results of the present study suggest that nifedipine may enhance the lipid lowering property of simvastatin.