Dipesh Kr. Das

Promising role of ferulic acid, atorvastatin and their combination in ameliorating high fat diet-induced stress in mice.

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 (10mg/kg) or F (100mg/kg) and both (10 and 100mg/kg) for 8weeks. 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.

Role of Ferulic Acid in the Amelioration of Ionizing Radiation Induced Inflammation: A Murine Model

Ionizing radiation is responsible for oxidative stress by generating reactive oxygen species (ROS), which alters the cellular redox potential. This change activates several redox sensitive enzymes which are crucial in activating signaling pathways at molecular level and can lead to oxidative stress induced inflammation. Therefore, the present study was intended to assess the anti-inflammatory role of ferulic acid (FA), a plant flavonoid, against radiation-induced oxidative stress with a novel mechanistic viewpoint. FA was administered (50 mg/kg body wt) to Swiss albino mice for five consecutive days prior to exposing them to a single dose of 10 Gy 60Co γ-irradiation. The dose of FA was optimized from the survival experiment and 50 mg/kg body wt dose showed optimum effect. FA significantly ameliorated the radiation induced inflammatory response such as phosphorylation of IKKα/β and IκBα and consequent nuclear translocation of nuclear factor kappa B (NF-κB). FA also prevented the increase of cycloxygenase-2 (Cox-2) protein, inducible nitric oxide synthase-2 (iNOS-2) gene expression, lipid peroxidation in liver and the increase of tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) in serum. It was observed that exposure to radiation results in decreased activity of superoxide dismutase (SOD), catalase (CAT) and the pool of reduced glutathione (GSH) content. However, FA treatment prior to irradiation increased the activities of the same endogenous antioxidants. Thus, pretreatment with FA offers protection against gamma radiation induced inflammation.

Epicatechin ameliorates ionising radiation-induced oxidative stress in mouse liver

Abstract The current study was intended to evaluate the hepatoprotective effect of Epicatechin (EC) against radiation-induced oxidative stress, in terms of inflammation and lipid peroxidation. Swiss albino mice were administered with EC (15 mg/kg body weight) for three consecutive days before exposing them to a single dose of 5-Gy 60Co gamma (γ) irradiation. Mice were necropsied and livers were taken for immunohistochemistry, western blot analysis and biochemical tests for the detection of markers of hepatic oxidative stress. Nuclear translocation of nuclear factor kappa B (NF-κB) and lipid peroxidation were increased whereas the activities of superoxide dismutase (SOD) and catalase (CAT), reduced glutathione (GSH) content and ferric reducing antioxidant power (FRAP) were diminished upon radiation exposure compared to control. Translocation of NF-κB from cytoplasm to nucleus and lipid peroxidation were found to be inhibited whereas an increase in SOD, CAT, GSH and FRAP was observed in the mice treated with EC prior to irradiation. Thus, pre-treatment with EC offers protection against γ-radiation induced hepatic alterations.

Naringin inhibits gamma radiation-induced oxidative DNA damage and inflammation, by modulating p53 and NF-κB signaling pathways in murine splenocytes

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.

Modulatory role of quercetin against gamma radiation-mediated biochemical and morphological alterations of red blood cells

Abstract Purpose: The present work was intended to evaluate the radioprotective effect of quercetin against gamma radiation-induced oxidative stress on red blood cells (RBC). Materials and methods: Swiss albino male mice were treated with quercetin (100 mg/kg body wt) for three consecutive days prior to 5 Gy 60Co-gamma irradiation. RBC was isolated to estimate the level of intracellular reactive oxygen species (ROS), membrane lipid peroxidation (LPO), intracellular reduced glutathione (GSH), mean corpuscular hemoglobin concentration (MCHC), osmotic fragility and morphological alterations by atomic force microscope (AFM). Results: Irradiation increased intracellular ROS and membrane LPO whereas it decreased the intracellular GSH. Quercetin pretreatment ameliorated these alterations. The MCHC value decreased after irradiation whereas quercetin pretreatment restored it. The average osmotic fragility (H50) and the maximum rate of hemolysis (dH/dC)max increased after irradiation. Quercetin pretreatment decreased the H50 and (dH/dC)max. The AFM study showed that irradiation transformed RBC from biconcave to echinocytes, increased their surface roughness and decreased the vertical distance whereas pretreatment of quercetin significantly prevented both the alterations. Conclusions: Gamma radiation produced ROS and LPO which rendered oxidative stress and ultimately damaged RBC whereas quercetin ameliorated these changes and protected RBC from radiation-mediated damage.

Gossypetin, a naturally occurring hexahydroxy flavone, ameliorates gamma radiation-mediated DNA damage

Abstract Purpose: To evaluate the protective effect of gossypetin (GTIN) against gamma (γ)-radiation-mediated DNA damage. Materials and methods: 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 Co60 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. Results: 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. Conclusions: GTIN ameliorated radiation-induced oxidative stress and DNA damage by its free-radical scavenging activity.

Biosynthesis of stabilised gold nanoparticle using an aglycone flavonoid, quercetin

Biosynthesis of gold nanoparticles (AuNPs) was obtained by a simple chemical reduction method using a plant-derived aglycone flavonoid, quercetin, as a reducing agent. The aqueous chloroauric acid when exposed to quercetin was reduced and converted to AuNPs in the size range from 20 to 45 nm. AuNPs were characterised by UV–visual spectroscopy, transmission electron microscopy, atomic force microscopy and dynamic light scattering method. These quercetin-mediated AuNPs have shown excellent stability for more than 30 days at 2–8°C. These quercetin-stabilised AuNPs will have an enormous potential for further conjugation studies since no other external stabilising agent is used.

Gossypetin ameliorates ionizing radiation-induced oxidative stress in mice liver--a molecular approach.

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.