Sumith Retnamma Panicker

Publications (2)6.22 Total impact

• Article: Quercetin attenuates Monocyte Chemoattractant Protein-1 gene expression in glucose primed aortic endothelial cells through NF-kappaB and AP-1.

  Sumith Retnamma Panicker, Prethish Sreenivas, Mani Sankar Babu, Devarajan Karunagaran, Chandrasekharan Cheranellore Kartha
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  ABSTRACT: Monocyte Chemoattractant Protein-1 (MCP-1) is involved in the diapedesis of blood monocytes into the arterial intima, an early critical event in atherogenesis. Modulating MCP-1 expression can be a key strategy to decrease the risk for atherosclerosis in diabetes. We hypothesized that quercetin, an anti-inflammatory molecule could modulate high glucose concentration (HG) induced MCP-1 expression in aortic endothelial cells in vitro because of its regulatory effects on Activator Protein-1 (AP-1) and Nuclear Factor-kappaB (NF-kappaB). Rat aortic endothelial cells (RAECs) were exposed to HG in the presence or absence of quercetin. Quercetin attenuated HG induced MCP-1 mRNA (42%) and protein synthesis (45%) when estimated using real-time reverse transcriptase-polymerase chain reaction and enzyme-linked immunosorbent assay respectively. Western blot analysis found quercetin to maintain cytosolic p65 protein levels to that seen in control. Quercetin was found to attenuate HG induced increased NF-kappaB and AP-1 DNA binding activity in electrophoretic mobility shift assay. Immunofluorescence studies revealed quercetin to prevent HG induced nuclear localization of p65 and c-jun. Quercetin was also found to decrease HG induced activation of NF-kappaB (71%+/-14%), AP-1 (69%+/-24%) and MCP-1 promoter (79%+/-25%) in EA.hy926 cells when analyzed using luciferase reporter assay. We conclude that quercetin attenuates MCP-1 expression in HG treated RAECs, probably by regulating both NF-kappaB and AP-1 pathways. The findings provide new insights into HG induced MCP-1 gene regulation in aortic endothelial cells and the potential of quercetin in abating the risk for atherosclerosis in diabetes.
  Pharmacological Research 10/2010; 62(4):328-36. · 4.44 Impact Factor
• Article: Curcumin attenuates glucose-induced monocyte chemoattractant protein-1 synthesis in aortic endothelial cells by modulating the nuclear factor-kappaB pathway.

  Sumith Retnamma Panicker, Chandrasekharan Cheranellore Kartha
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  ABSTRACT: High glucose (HG) induces monocyte chemoattractant protein-1 (MCP-1) synthesis in endothelial cells through nuclear factor kappaB (NFkappaB). We investigated whether curcumin, losartan and sodium salicylate (NaSal) attenuate HG-induced MCP-1 synthesis in rat aortic endothelial cells (RAECs) and explored the mechanism of action. RAECs were stimulated with HG (25 mmol/l) for 24 h in the presence or absence of curcumin, losartan, NaSal or NFkappaB inhibitor, Bay 11-0782. The MCP-1 protein and mRNA levels were determined by enzyme-linked immunosorbent assay and real-time reverse transcriptase-polymerase chain reaction, respectively. Nuclear translocation of NFkappaB subunit p65 and NFkappaB DNA-binding activity was studied using confocal microscopy and electrophoretic mobility shift assay, respectively. A significant increase in the synthesis of MCP-1 protein and mRNA (2-fold) was observed in HG-primed RAECs compared to control glucose (5.5 mmol/l). Curcumin (30 micromol/l) significantly decreased HG-induced MCP-1 protein (74%) and mRNA (53%) synthesis. There was no inhibition of HG-induced MCP-1 protein secretion by losartan and NaSal. In HG-stimulated RAECs, curcumin attenuated the nuclear translocation of p65 and decreased the NFkappaB DNA-binding activity. Curcumin blocks HG-induced MCP-1 synthesis in RAECs partly via the NFkappaB pathway.
  Pharmacology 12/2009; 85(1):18-26. · 1.79 Impact Factor