Browsing by Author "Gayathri, V"

Now showing 1 - 12 of 12
  • Item
    An in vitro study on the interaction of hydroxyapatite nanoparticles and bone marrow mesenchymal stem cells for assessing the toxicological behaviour
    (COLLOIDS AND SURFACES B-BIOINTERFACES, 2014) Remya, NS; Syama, S; Gayathri, V; Varma, HK; Mohanan, PV
    Mesenchymal stem cells or multipotent progenitor cells isolated from bone marrow presents close resemblance to the natural in vivo milieu and hence preferred more than the conventional cell culture systems to predict the toxicological behavior of bio-nano interaction. The objective of the present study is to evaluate the molecular toxicity of hydroxyapatite nanoparticles (HANPs) using mouse bone marrow mesenchymal stem cells (BMSCs). In-house synthesized HANPs (50 nm) were used to study the cytotoxicity, nano particle uptake, effect on cyto skeletal arrangement, oxidative stress response and apoptotic behavior with the confluent BMSCs as per standard protocols. The results of the MIT assay indicated that HANPs does not induce cytotoxicity up to 800 mu g/mL. It was also observed that oxidative stress related apoptosis and reactive oxygen species (ROS) production following nanoparticle treatment was similar to that of control (cells without treatment). Hence it can be concluded that the in-house synthesized HANPs are non-toxic/safe at the molecular level suggesting that the HANPs are compatible to BMSCs. Further, the in vitro BMSCs cell culture can be used as a model for evaluating the preliminary toxicity of nanomaterials. (C) 2014 Elsevier B.V. All rights reserved.
  • Item
    Assessing the systemic toxicity in rabbits after sub acute exposure of known ocular irritant chemicals
    (Toxicological Research, 2015-06) Reshma, SC; Sruthi, S; Syama, S; Gayathri, V; Mohanan, PV
    Eye is a highly vascularised organ. There are chances that a foreign substance can enter the systemic circulation through the eye and cause oxidative stress and evoke immune response. Here the eyes of rabbits were exposed, for a period of 7 days, to 5 known ocular irritants: Cetyl pyridinium chloride (CPC), sodium salicylate (SS), imidazole (IMI), acetaminophen (ACT) and nicotinamide (NIC). The eyes were scored according to the draize scoring. Blood collected from the treated rabbit were analyzed for haematological and biochemical parameters. After sacrifice, histological analysis of the eye and analysis of pro-inflammatory biomarkers (IL-1α, IL-1β, IL-8 and TNF-α) in the cornea using ELISA was carried out. Spleen was collected and the proliferation capacities of spleenocytes were analyzed. Liver and brain were collected and assessed for oxidative stress. The eye irritation potential of the chemicals was evident from the redness and swelling of the conjunctiva and cornea. Histopathological analysis and ELISA assay showed signs of inflammation in the eye. However, the haematological and biochemical parameters showed no change. Spleenocyte proliferations showed only slight alterations which were not significant. Also oxidative stress in the brain and liver were negligible. In conclusion, chemicals which cause ocular irritation and inflammation did not show any systemic side-effects in the present scenario
  • Item
    Assessment of hydroxyapatite nanoparticles induced oxidative stress- An in vitro study.
    (J Free Rad Antioxidants, 2014) Syama, S; Reshma, SC; Gayathri, V; Varma, HK; Mohanan, PV
  • Item
    Assessment of Immunotoxicity of Dextran Coated Ferrite Nanoparticles in Albino Mice
    (Molecular Biology International, 2015-10) Syama, S; Gayathri, V; Mohanan, PV
    In this study, dextran coated ferrite nanoparticles (DFNPs) of size <25 nm were synthesized, characterized, and evaluated for cytotoxicity, immunotoxicity, and oxidative stress by in vitro and in vivo methods. Cytotoxicity was performed in vitro using splenocytes with different concentrations of DFNPs. Gene expression of selected cytokines (IL-1, IL-10, and TNF 𝛽) secretion by splenocytes was evaluated. Also, 100 mg of DFNPs was injected intraperitoneally to 18 albino mice for immunological stimulations. Six animals each were sacrificed at the end of 7, 14, and 21 days. Spleen was subjected to immunotoxic response and liver was analyzed for antioxidant parameters (lipid peroxidation, reduced glutathione, glutathione peroxidase, superoxide dismutase, and glutathione reductase). The results indicated that DFNPs failed to induce any immunological reactions and no significant alternation in antioxidant defense mechanism. Also, mRNA expression of the cytokines revealed an increase in IL-10 expression and subsequent decreased expression of IL-1 and TNF 𝛽. Eventually, DNA sequencing of liver actin gene revealed base alteration in nonconserved regions (10–20 bases) of all the treated groups when compared to control samples. Hence, it can be concluded that the DFNPs were nontoxic at the cellular level and nonimmunotoxic when exposed intraperitoneally to mice.
  • Item
    Assessment of Immunotoxicity of Dextran Coated Ferrite Nanoparticles in Albino Mice
    (Molecular Biology International., 2015-12) Syama, S; Gayathri, V; Mohanan, PV
    In this study, dextran coated ferrite nanoparticles (DFNPs) of size <25 nm were synthesized, characterized, and evaluated for cytotoxicity, immunotoxicity, and oxidative stress by in vitro and in vivo methods. Cytotoxicity was performed in vitro using splenocytes with different concentrations of DFNPs. Gene expression of selected cytokines (IL-1, IL-10, and TNF β) secretion by splenocytes was evaluated. Also, 100 mg of DFNPs was injected intraperitoneally to 18 albino mice for immunological stimulations. Six animals each were sacrificed at the end of 7, 14, and 21 days. Spleen was subjected to immunotoxic response and liver was analyzed for antioxidant parameters (lipid peroxidation, reduced glutathione, glutathione peroxidase, superoxide dismutase, and glutathione reductase). The results indicated that DFNPs failed to induce any immunological reactions and no significant alternation in antioxidant defense mechanism. Also, mRNA expression of the cytokines revealed an increase in IL-10 expression and subsequent decreased expression of IL-1 and TNF β. Eventually, DNA sequencing of liver actin gene revealed base alteration in nonconserved regions (10–20 bases) of all the treated groups when compared to control samples. Hence, it can be concluded that the DFNPs were nontoxic at the cellular level and nonimmunotoxic when exposed intraperitoneally to mice.
  • Item
    Attenuation of Cisplatin Induced Toxicity by Melatonin, Loaded on a Dextran Modified Iron Oxide Nanoparticles: An In Vitro Study
    (J Forensic Toxicol Pharmacol, 2015-06) Shyma, MS; Ansar, EB; Gayathri, V; Varma, HK; Mohanan, PV
    Conjugation drug therapy of melatonin has emerged as a promising modality for reducing cisplatin (cis-diammine di chloro platinum (II) or cis-DDP or CDDP) induced toxicity. The objective of the present study is to determine the attenuation of cisplatin induced toxicity by Melatonin loaded on a Dextran modified Iron Oxide nanoparticles (DIO-M). The DIO-M was developed, characterized and analyzed. Loading of melatonin was confirmed by Fouriertransform infrared spectroscopy (FTIR). Particle size analysis was carried out using Dynamic Light Scattering (DLS) and Transmission Electron Microcope (TEM) techniques. Phase purity of crystals was determined by X-ray diffraction analysis (XRD) and the magnetic property of particle material was characterized by Vibrational sample magnetometry (VSM). Cytotoxicity studies using by MTT assay in L929 cell lines confirmed the melatonin nanoparticles to be nontoxic. The protective effect of DIO-M against cisplatin induced toxicity was confirmed by antioxidant parameters such as reduced glutathione, superoxide dismutase, and glutathione peroxidase and glutathione reductase. Free radical mediated cell damage was quantitatively determined by the measurement of malondialdehyde level. It was found that the inhibitory effect of malondialdehyde levels by DIO-M could be attributed to the increased activities of antioxidant enzymes (p<0.005). Splenocyte proliferation demonstrated that DIO-M has the ability to influence the spleen cells. Splenocytes when treated with cisplantin and DIO-M was able to overcome the antiproliferative property of cisplatin. Hence, these findings contribute with important insight that DIO-M can be useful for management of toxicity induced by anti-cancer drug cisplatin.
  • Item
    Evaluation of Toxicity of Maura Reduced Graphene Oxide using In vitro Systems
    (J Nanomed Nanotechnol., 2014) Cherian, RS; Sreejith, R; Syama, S; Sruthi, S; Gayathri, V; Maekawa, T; Sakthikumar, D; Mohanan, PV
    The intriguing properties of graphene has paved way for many potential biomedical applications like drug delivery, tissue engineered scaffold, bio sensing and so on. Here, we report the interaction of Maura reduced graphene oxide (MRGO) with the peripheral blood mononuclear cells (PBMNCs), as there is a likelihood of graphene coming in contact with the blood through intentional or accidental exposure. MRGO was synthesized by reducing graphene oxide using Halomonas Maura and autoclaved subsequently to prevent microbial contamination. It was characterized by TEM, AFM and FITR. Initial cytotoxicity was conducted in L929 cells to get the dose response. Oxidative stress potential, effect on proliferative capacity, genotoxicity and induction of apoptosis in PBMNCs treated with MRGO were assessed. MRGO elicited a dose dependent ROS generation which promoted apoptosis in PBMNCs. Proliferation of these cells were also found to be hindered. However, MRGO did not induce genotoxicity and generation of reactive nitrogen species. In conclusion MRGO shows a dose dependent toxicity in cells, generating ROS, inducing apoptosis and affecting proliferation, which may be due to the loss of exopolysaccharide coating due to autoclaving. This study raises a serious concern regarding the in vivo biomedical application of MRGO, where IV and IP are the main routes of exposure. Further evaluation is required regarding the interaction of autoclaved MRGO with the blood cells.
  • Item
    An in vitro study on the interaction of hydroxyapatite nanoparticles and bone marrow mesenchymal stem cells for assessing the toxicological behavior
    (Colloids Surf B Biointerfaces, 2014-05) Remya, NS; Syama, S; Gayathri, V; Varma, HK; Mohanan, PV
    Mesenchymal stem cells or multipotent progenitor cells isolated from bone marrow presents close resemblance to the natural in vivo milieu and hence preferred more than the conventional cell culture systems to predict the toxicological behavior of bio-nano interaction. The objective of the present study is to evaluate the molecular toxicity of hydroxyapatite nanoparticles (HANPs) using mouse bone marrow mesenchymal stem cells (BMSCs). In-house synthesized HANPs (50 nm) were used to study the cytotoxicity, nano particle uptake, effect on cyto skeletal arrangement, oxidative stress response and apoptotic behavior with the confluent BMSCs as per standard protocols. The results of the MTT assay indicated that HANPs does not induce cytotoxicity up to 800 μg/mL. It was also observed that oxidative stress related apoptosis and reactive oxygen species (ROS) production following nanoparticle treatment was similar to that of control (cells without treatment). Hence it can be concluded that the in-house synthesized HANPs are non-toxic/safe at the molecular level suggesting that the HANPs are compatible to BMSCs. Further, the in vitro BMSCs cell culture can be used as a model for evaluating the preliminary toxicity of nanomaterials.
  • Item
    Induction of immunotoxicity and oxidative stress by imidazole on immune cells
    (Applied Cell Biology, 2015-07) Gayathri, V; Mohanan, PV
    Imidazole is a known irritant to rabbit eye and possesses moderate oral toxicity. However Imidazole toxicity to immune cells if any, is unclear therefore needs to be scientifically evaluated. Aim of the present study was to evaluate the immuno-toxicity properties, if any, of imidazole par- ent compound. The study included assessment of the expression of im- mune modulatory cytokine mediators using real time PCR from the total RNA, isolated from mixed and T lymphocytes. Nitrosative stress was assessed by Nitric oxide formation. Apoptotic potential of imidazole on T lymphocytes using Annexin V assay kit was carried out using flow cytometer. Higher concentration of imidazole (10mg/ml) showed a sig- nificant increase in pro inflammatory cytokines like interleukin-1, mono- cyte chemo attractant protein-1, tumour necrosis factor beta, whereas drastic reduction in anti inflammatory cytokine, interleukin -10 was noted. This study also demonstrated that Imidazole (10 mg/ml) induces mixed and T lymphocyte proliferation by DNAsynthesissignificantly. The mRNA expressions of mitogen-activated protein kinases 14 gene, inducible Nitric oxide synthase and Bcl-2ñassociated X protein were also signifi- cantly increased (p<0.01). However, lower concentrations of imidazole did not exhibit such effect on both types of cells. Continuous exposure of workers to imidazole used in industries could suppress the bodyís immune system, especially cellular immunity thereby triggering the inflammatory pathway and targeting the p38 MAPK signal transduction pathway. These observations are of interest in view of workers in pesti- cide, pharmaceutical industries
  • Item
    Induction of oxidative stress and lymphocyte proliferation by nanohydroxyapatite in mice
    (Journal of Basic & Applied Research International, 2015-06) Lekshmy, MS; Gayathri, V; Sabareeswaran, A; Mohanan, PV
    The aim of this study is to evaluate the potential impact of intraperitoneally administered nanohydroxyapatite on the liver oxidative status and also to study the immunogenicity of the administered nanohydroxyapatite in Swiss albino mice. Biochemical estimation of the lipid peroxidation, reduced glutathione and the activities of the Glutathione peroxidase, Glutathione reductase and the Superoxide dismutase in the liver were carried out following 7, 14 and 21 days post-treatment with nanohydroxyapatite. Tritiated thymidine uptake studies were done with the splenic lymphocytes for studying the immunogenic potential. Histopathological evaluation of the liver, spleen and the kidney was also carried out. There was marked reduction in the reduced glutathione levels and in the activities of the antioxidant enzymes GPX, GR and SOD at 7 and 14 day and further showed an increase by the 21 day. The LPO levels showed a significant increase by the 21 day. The T lymphocytes proliferated by two-fold by the 7 day and returned to normal levels by the 14 day and an increase was seen by the 21 days. There was no histopathological lesion observed in the treated groups. The nanohydroxyapatite treatment lead to a marked reduction in the levels of the antioxidant enzyme activities which however increases by the 21 day indicating that the body is able to defend against the oxidative stress mounted by the nanohydroxyapatite. Nanohydroxyapatite has immunogenic potential as it was able to elicit proliferation of the T lymphocytes up to 21 days.
  • Item
    Integration of Rabbit Adipose Derived Mesenchymal Stem Cells to Hydroxyapatite Burr Hole Button Device for Bone Interface Regeneratio
    (International Journal of Biomaterials, 2016-01) Gayathri, V; Varma, HK; Mohanan, PV
    Adipose Derived Mesenchymal Stem Cells, multipotent stem cells isolated from adipose tissue, present close resemblance to the natural in vivo milieu and microenvironment of bone tissue and hence widely used for in bone tissue engineering applications. The present study evaluates the compatibility of tissue engineered hydroxyapatite burr hole button device (HAP-BHB) seeded with Rabbit Adipose Derived Mesenchymal Stem Cells (ADMSCs). Cytotoxicity, oxidative stress response, apoptotic behavior, attachment, and adherence of adipose MSC seeded on the device were evaluated by scanning electron and confocal microscopy. The results of the MTT (3-(4,5-dimethylthiazol)-2,5-diphenyl tetrazolium bromide) assay indicated that powdered device material was noncytotoxic up to 0.5 g/mL on cultured cells. It was also observed that oxidative stress related reactive oxygen species production and apoptosis on cell seeded device were similar to those of control (cells alone) except in 3-day period which showed increased reactive oxygen species generation. Further scanning electron and confocal microscopy indicated a uniform attachment of cells and viability up to 200 μm deep inside the device, respectively. Based on the results, it can be concluded that the in-house developed HAP-BHB device seeded with ADMSCs is nontoxic/safe compatible device for biomedical application and an attractive tissue engineered device for calvarial defect regeneration.
  • Item
    Protective Effect of Melatonin On Kainic acid Induced-Liver Damage And Immune Modulatory Cytokines
    (Immunome Res., 2014) Gayathri, V; Neelima, R; Mohanan, PV
    Liver toxicity occurs when liver develops inflammation due to exposure to several toxic substances. The study was aimed to assess the liver damage induced by kainic acid and subsequently protective role of exogenous melatonin against the liver toxicity. Interestingly, kainic acid caused severe liver damage as evident from deleterious alterations in liver histology, increased lipid peroxide levels, decrease in the activities of liver anti-oxidant enzymes, DNA damage (adduct formation and sequence alterations), increased expression of cytokines like monocyte chemoattractant protein-1, interleukin 6, interferon γ and decreased expression of interleukin 10. These changes were normalized by melatonin (0.5-1.0 mM, (in vitro) or 10–20 mg/kg, (in vivo)). The study included assessment of the expression of immune modulatory cytokine mediators using real time PCR in both in vitro and in vivo conditions in the mouse liver. DNA damage was also studied. Various oxidative stress parameters and liver histopathology was also evaluated. Melatonin’s anti-kainic acid toxicity could be brought about by counter acting the influence of kainic acid on the levels of the cytokines, immune reactions and free radical production. This work suggests that melatonin receptors present could be mediate the hepatoprotective actions of melatonin therapy.