significantly higher in POS women with insomnia than PRE women without insomnia (0.364±0.05 vs. 0.317±0.04 μmol/L, p=0.001). LPO decreased after 6 months in HT group (0.346±0.06 vs. 0.307±0.07 μmol/L, P<0.05); GPx increased (52.2±18.6 vs. 65.5±11.3 U/gHb, p=0.001) and AIS score also decreased (9±5 vs. 5±4, p=0.001); PRE and P did not change. the women with high LPO levels and insomnia in HT decreased after 6 month, pre-treatment 13 (42%) to 3(10%) post-treatment (P<0.05), and the other groups did not change. Our findings suggest that HT decreases OS and insomnia in posmenopausal women. This work was supported by grant DGAPA-UNAM IN306111 and sponsored by Laboratorios Senosiain SA de CV. Trial registration: COF000120.

doi:10.1016/j.freeradbiomed.2011.10.467

229 S-Allylmercapto-N-acetylcysteine (ASSNAC) Up-Regulates Brain Glutathione Level and Attenuates Experimental Autoimmune Encephalomyelitis Naphtali Savion1, Nira Izigov1, Milana Morein1, Nahid Farzam1, and Sarah Pri-Chen2 1Tel Aviv University, 2Sheba Medical Center Oxidative stress is associated with development and progression of numerous neurodegenerative diseases such as multiple sclerosis (MS). We have previous shown that allicin (diallyl thiosulfinate) and its newly synthesized derivative, S-allylmercapto-N-acetylcysteine (ASSNAC) up-regulates both glutathione level and the expression of phase II detoxifying enzymes in cultured vascular endothelial cells and neuroblastoma SH-SY5Y cells. the proposed mechanism of action of ASSNAC is: (i) high cell and tissue permeability due to the hydrophobic nature of the S-allyl mercaptan residue; (ii) attacking free sulfhydryls by the thiol-disulfide exchange reaction resulting in induced expression of phase II detoxifying enzymes and release of free N-acetylcyteine, both increasing glutathione synthesis; (iii) up-regulation of the cystine transporter (xCT) expression thereby increasing cellular cysteine. This study is aimed to test the effect of ASSNAC on the development of myelin oligodendrocyte glycoprotein (MOG) induced experimental autoimmune encephalomyelitis (EAE) disease, a mouse model of MS. the EAE disease induced by MOG injection resulted in the development of paralysis symptoms starting on day 16 increasing up to a maximal score of 2.5 (mean of 8 mice) on day 30 following MOG injection. On the other end, if the MOG treated mice were daily treated with ASSNAC (50 mg/kg/day) a significant reduction in the paralysis symptoms to a score of 0.5 (mean of 8 mice; P<0.001) was observed. the glutathione level in the brain of the MOG treated mice, on day 35, was slightly (26%) higher than the control level, while that of the ASSNAC treated mice was significantly higher (47%; P<0.05) than the control level. in conclusion, this study suggests that ASSNAC, a conjugate of the natural compounds, allicin and N-acetylcysteine, is highly hydrophobic and therefore may better penetrate into tissues and cells including the brain. It reacts with free cellular sulfhydryls resulting in de novo glutathione biosynthesis and induces phase II detoxifying enzymes. the induction of these mechanisms results in increased glutathione level in the brain of EAE mice in association with attenuation of the clinical symptoms of EAE.

doi:10.1016/j.freeradbiomed.2011.10.468

230 Nox4 Controls Bone Mass by Regulation of Osteoclastogenisis Katrin Schröder1, Claudia Göttsch2, Lorenz C. Hofbauer2, Reinhold G Erben3, and Ralf P. Brandes1 1Goethe-Universität, Frankfurt, Germany, 2TU, Dresden, Germany, 3University of Veterinary Medicine, Vienna, Austria NADPH oxidases (Nox) are important sources of reactive oxygen species (ROS), which have been implicated in osteoclastogenesis. the contribution of individual Nox proteins in osteoclastogenesis is unknown. We generated a Nox4 deficient mouse (Nox4-/-) and determined the impact of Nox4 on osteoclastogenesis and subsequently bone mass in mice. Nox4-/- mice displayed higher bone density and reduced numbers and markers of osteoclasts. Interestingly a significant increase in trabecular thickness and width was observed in Nox4-/- mice, whereas the trabecular number and separation were not altered when compared to their wildtype littemates. Bones form Nox4-/- mice showed lower level of osteoclast-associated receptor (OSCAR), when compared to wildtype as measured by Western blot. These data point towards an osteoclast phenotype in Nox4-/- mice. Indeed, the number of osteoclasts per bone area was significantly lower in Nox4-/- mice as demonstrated by TRAP (tartrate-resistant acid phosphatase) staining. Ex vivo, differentiation of monocytes into osteoclasts with RANKL and M-CSF induced Nox4 expression. Loss of Nox4 activity attenuated osteoclastogenesis as a consequence of an impaired RANKL-induced NFAT1c and c-Jun activation. In conclusion, deficiency of Nox4 causes a high bone mass phenotype due to impaired osteoclastogenesis.

doi:10.1016/j.freeradbiomed.2011.10.469

231 Effects of Hyperbaric Oxygen (HBO) Preconditioning On Plasma Constituents Eilam Palzur1, Khatib Soliman2, Jacob Vaya2, Ilan Chezar 1, Regina Michelis1, and Shifra Sela1,3 1Western Galilee Hospital, Nahariya, 2Oxidative Stress Research Laboratory, MIGAL-Galilee Technology Center, 3Bar Ilan University,Galilee Faculty of Medicine, Israel HBO is commonly used in the treatment of tissue hypoxia or ischemia, and is based on the ability of oxygen to effectively dissolve in blood (20 times greater than under atmospheric conditions). However, in some cases, exposure to HBO may cause adverse effects, leading to oxygen toxicity of the central nerve system. It is accepted that HBO leads to increased formation of reactive oxygen species (ROS), which play a major role in cell injury, underlying various pathologies. N-linoleoyl tyrosine (LT) is an exogenous marker sensitive to oxidative stress (OS) as it is composed of linoleic acid and tyrosine, representing lipids and proteins respectively. Under OS, LT subunits are oxidized reflecting the susceptibility of the body lipids and proteins to oxidative damage. Hypothesis: Exposure to HBO will result in oxidative damage, manifested by oxidized LT and blood constituents. Preconditioning with multiple short HBO exposures prior to a long one will attenuate the induced oxidative damage. Methods: Three groups of rats were used: "HBO" rats received a single long HBO exposure: 2.8 ATA for 90min; "Pre conditioned" rats, received daily exposure of 2.8 ATA for 20min, for 4 days, followed by one "long" exposure on the fifth day; and "unexposed" rats as a control group. the oxidized LT marker was analyzed by LC/MS/MS, following its incubation with blood drawn prior and following HBO exposures. in addition, protein oxidation products

SFRBM 2011 S97