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Mediators of Inflammation
Volume 2013, Article ID 741804, 20 pages
Research Article

Biphasic Modulation of NOS Expression, Protein and Nitrite Products by Hydroxocobalamin Underlies Its Protective Effect in Endotoxemic Shock: Downstream Regulation of COX-2, IL-1 , TNF- , IL-6, and HMGB1 Expression

1The William Harvey Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, UK
2Far Manguinhos—FIOCRUZ, R. Sizenando Nabuco 100, 21041-250 Rio de Janeiro, RJ, Brazil
3Department of Science, University of Basilicata, Potenza, Italy
4Orthomolecular Oncology, Registered Charity No. 1078066, 4 Richmond Road, Oxford OX1 2JJ, UK
5St Catherine’s College, Oxford University, Manor Road, Oxford OX1 3UJ, UK

Received 21 December 2012; Revised 19 February 2013; Accepted 19 February 2013

Academic Editor: Fábio Santos Lira

Copyright © 2013 André L. F. Sampaio et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Background. NOS/NO inhibitors are potential therapeutics for sepsis, yet they increase clinical mortality. However, there has been no in vivo investigation of the (in vitro) NO scavenger, cobalamin’s (Cbl) endogenous effects on NOS/NO/inflammatory mediators during the immune response to sepsis. Methods. We used quantitative polymerase chain reaction (qPCR), ELISA, Western blot, and NOS Griess assays, in a C57BL/6 mouse, acute endotoxaemia model. Results. During the immune response, pro-inflammatory phase, parenteral hydroxocobalamin (HOCbl) treatment partially inhibits hepatic, but not lung, iNOS mRNA and promotes lung eNOS mRNA, but attenuates the LPS hepatic rise in eNOS mRNA, whilst paradoxically promoting high iNOS/eNOS protein translation, but relatively moderate NO production. HOCbl/NOS/NO regulation is reciprocally associated with lower 4 h expression of TNF- , IL-1β, COX-2, and lower circulating TNF- , but not IL-6. In resolution, 24 h after LPS, HOCbl completely abrogates a major late mediator of sepsis mortality, high mobility group box 1 (HMGB1) mRNA, inhibits iNOS mRNA, and attenuates LPS-induced hepatic inhibition of eNOS mRNA, whilst showing increased, but still moderate, NOS activity, relative to LPS only. experiments (LPS+D-Galactosamine) HOCbl afforded significant, dose-dependent protection in mice Conclusions. HOCbl produces a complex, time- and organ-dependent, selective regulation of NOS/NO during endotoxaemia, corollary regulation of downstream inflammatory mediators, and increased survival. This merits clinical evaluation.