ABSTRACT
Depletion of glutathione levels and perturbations in redox status are considered to play a crucial role in aging and chronic inflammatory processes through the activation of redox sensitive transcription factors, including nuclear factor-kappaB (NF-kappaB). In the current study, we assessed the regulatory action of dietary betaine in the suppression of NF-kappaB by comparing kidney tissue from old, betaine-supplemented rats or non-betaine-supplemented rats (age 21 months) and 7 month-old rats. In addition, cultured HEK 293T cells were utilized for the molecular assessment of betaine's restorative ability of redox status when treating cells with potent glutathione (GSH)-depleting agents. Results showed that in old rats a short-term feeding (10 d) with betaine attenuated the age-related decrease in thiol levels, increase in reactive species and TNFalpha expression via NF-kappaB activation, compared to the young controls. These findings were verified in the cell-cultured system. Further investigations found that redox imbalance due to thiol depletion caused increased NF-kappaB activation, and cyclooxygenase (COX)-2 and TNFalpha levels, both of which were suppressed by betaine treatment. Based on both in vivo and in vitro data, we concluded that betaine exerts its efficacy by maintaining thiol status in the regulation of COX-2 and TNFalpha via NF-kappaB activation during aging.
Subject(s)
Aging/physiology , Antioxidants/pharmacology , Betaine/pharmacology , NF-kappa B/biosynthesis , Sulfhydryl Compounds/metabolism , Animals , Blotting, Western , Body Weight/drug effects , Cell Nucleus/drug effects , Cell Nucleus/metabolism , Cells, Cultured , Cyclooxygenase 2/biosynthesis , Diet , Glutathione/metabolism , Humans , Kidney/drug effects , Kidney/metabolism , Male , Oxidation-Reduction , Oxidative Stress/physiology , Rats , Rats, Sprague-Dawley , Tumor Necrosis Factor-alpha/biosynthesis , Tumor Necrosis Factor-alpha/metabolismABSTRACT
Intravenous (IV) busulfan has been developed to overcome variable absorption of oral busulfan and tested in several trials. We tested its pharmacological properties and tolerability in 16 Korean stem cell transplantation (SCT) patients. IV busulfan was administered at 0.8 mg/kg every six h for a total of 16 doses (days -7 to -4), which was followed by cyclophosphamide administration at 60 mg/kg every 24 h for two d (days -3 and -2). The median AUC(inf) values (at the first dose) and AUC(ss) (at the steady state) were 1060.4 microM.min (range: 511.1-1812.7) and 1092.5 microM.min (range: 539.7-1560.8) respectively. All patients had an AUC(inf) of <1500 microM.min at the first dose, and 13 of the 16 (81.3%) maintained AUC(ss) levels between 800 and 1500 microM.min. Thirteen of 16 patients showed successful engraftments but four patients (25%) developed hepatic VOD (two of which were fatal), three of whom had advanced disease at the time of SCT. Overall, pharmacokinetics of IV busulfan in our SCT patients appeared comparable with those observed in other study. However, hepatic VOD was a major morbidity in patients with advanced disease.
