Cytotoxic and antioxidant activity of selected marine sponges

ObjectiveTo evaluate the anticancer activity of the crude extracts of Rhabdastrella globostellata (R. globostellata) and Spirastrella inconstans (S. inconstans) var. moeandrina Dendy.MethodsSoxhlet extraction method was used to extract the secondary metabolites and various assays antioxidant, anticancer and various assays were carried out. The extract were tested anticancer activity against a HeLa, Raw 264.7 and Hek-293.ResultsThe sponge extracts tested exhibited from median to high toxicity in at least one of the toxicity bioassays performed. The antioxidant activity of the isolated metabolite in ethylacetate solution was assessed by SOD and GTH assays and compared with that of other known natural antioxidants.ConclusionsPotent antioxidants have been detected among both phenolic metabolites and alkaloids. Antioxidant effects of tested compounds have been attributed to their action as chain-breaking antioxidants and/or as scavengers of radicals     

International Academy of Cardiovascular Sciences,Japanese Section Meeting: July 7 to 8, 2012, Tokyo,Japan

BACKGROUND:

An excessive immune-mediated inflammation is associated with cardiac dysfunction and poor clinical outcomes after myocardial infarction (MI). However, the precise regulatory mechanism to control the inflammatory response and subsequent tissue repair following MI is unclear.

METHODS AND RESULTS:

Bone-marrow (BM) cells from CD11c-diphtheria toxin receptor/GFP transgenic mice were transplanted into lethally irradiated wild-type (WT) recipient mice. After reconstitution of BM-derived cells, the recipient mice were treated with either diphtheria toxin (DC ablation) or vehicle (control), and MI was created by left coronary ligation. CD11c⁺ GFP⁺ DCs expressing CD11b and MHC class II were recruited into the heart, peaking on day 7 after MI in control group. Mice with DC ablation for 7 days showed deteriorated left ventricular (LV) function and remodeling. The DC-ablated group demonstrated enhanced and sustained expression of inflammatory cytokines, prolonged extracellular matrix degradation associated with a high level of matrix metalloproteinase-9 activity, and diminished expression level of interleukin (IL)-10 and endothelial cell proliferation post-MI compared with control group. In vivo and in vitro analyses revealed that DC-ablated infarcts had an enhanced capacity of monocyte/macrophage recruitment. Among these cells, augmented infiltration of proinflammatory Ly6Chigh monocytes and F4/80⁺ CD206 M1 macrophages and, conversely, impaired recruitment of anti-inflammatory Ly6Clow monocytes and F4/80⁺ CD206⁺ M2 macrophages in the infarcted myocardium were identified in DC-ablated group than in control group. Flow cytometric analysis for inflammatory cells extracted from infarcted tissue revealed that CD11c⁺ DC is one of the major sources of IL-10. Adoptive transfer of BM-derived DCs from WT, but not IL-10-deficient mice, abrogated the adverse effects of DC depletion on inflammatory response and LV remodeling after MI.

CONCLUSION:

DC could be a potent immunoprotective regulator during the postinfarction healing process, via controlling monocyte/macrophage homeostasis through IL-10 secretion.

• Exp Clin Cardiol. 2012 Summer; 17(2): 50–58.
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• Y-2: Cardiac Nuclear High Mobility Group Box 1 Prevents Cardiac Dysfunction Induced by Pressure Overload

Exp Clin Cardiol. 2012 Summer; 17(2): 50. Abstracts

Y-2: Cardiac Nuclear High Mobility Group Box 1 Prevents Cardiac Dysfunction Induced by Pressure Overload

Akira Funayama, Tetsuro Shishido, and Isao KubotaAuthor information Copyright and License information DisclaimerDepartment of Cardiology, Pulmonology and Nephrology, Yamagata University School of Medicine, Yamagata, JapanCopyright © 2012, Pulsus Group Inc. All rights reserved     

Bacillus pumilus of Palk Bay origin inhibits quorum-sensing-mediated virulence factors in Gram-negative bacteria

The aim of the current study was to inhibit quoring-sensing(QS)-mediated virulence factors of representative Gram-negative bacteria by marine bacterial isolates. Bacteria isolated from Palk Bay sediments were screened for anti-QS activity. Eleven strains inhibited QS signals in Chromobacterium violaceum (ATCC 12472) and C. violaceum CV026. The marine bacterial strain S8-07 reduced the accumulation of N-acyl homoserine lactone (AHLs) and showed significant inhibition of LasA protease(76%), LasB elastase(84%), caseinase(70%), pyocyanin (84%), pyoverdin and biofilm formation(87%) in Pseudomonas aeruginosa PAO1. Strain S8-07 also showed highly significant reduction (90%) in prodigiosin, secreted casienase (92%), hemolytic activity (73%) and biofilm formation (61%) in Serratia marcescens. Strain S8-07, identified as Bacillus pumilus (accession number FJ584416), showed distinct profiles of inhibition against the virulence factors of both P. aeruginosa PAO1 (las, rhl) and S. marcescens (shl). Polar extraction and proteinase K treatment of the culture supernatant confirmed that the anti-QS activity of S8-07 was indeed due to a protein molecule. Acidification assay and HPLC analysis revealed that the degradation of AHL was not due to lactonase activity, but rather, was due to acylase activity of S8-07. Thus, novel anti-QS acylase activity is reported for the first time from a B. pumilus strain of marine origin.