Direct assessment of the antioxidant properties of midazolam by electron spin resonance spectroscopy

Evaluation of Mitochondrial Oxidative Stress in the Brain of a Transgenic Mouse Model of Alzheimer's Disease by in vitro Electron Paramagnetic Resonance Spectroscopy

Alzheimer's disease (AD) is one of the most common neurodegenerative diseases responsible for progressive dementia. Deposition of amyloid-β (Aβ) in the brain is the most important pathophysiological hallmark of AD. In addition, recent evidence indicates that reactive oxygen species (ROS) derived from mitochondria contribute to progression of AD pathology. We thus hypothesized that Aβ accumulates and oxidative stress increases in the brain mitochondria of a transgenic mouse model of AD (APdE9). We measured the quantity of Aβ and the activity of the antioxidant enzyme superoxide dismutase (SOD) in brain mitochondrial fractions prepared from APdE9 and wild-type (WT) mice aged 6, 9, 15, and 18 months. We also quantified the age-related changes in redox status in the mitochondrial fractions obtained from both APdE9 and WT mouse brains by electron paramagnetic resonance (EPR) spectrometry using a paramagnetic nitroxide "Mito-Tempo" [(2-(2,2,6,6-Tetramethylpiperidin-1-oxyl-4-ylamino)-2-oxoethyl) triphenylphosphonium chloride monohydrate] as a mitochondria-targeted redox-sensitive probe. In APdE9 mice, Aβ accumulated in brain mitochondria earlier than in the non-mitochondrial fraction of the brain. Furthermore, increased oxidative stress was demonstrated in brain mitochondria of APdE9 mice by in vitro SOD assay as well as EPR spectroscopy. EPR combined with a mitochondria-targeted redox-sensitive nitroxide probe is a potentially powerful tool to elucidate the etiology of AD and facilitate the development of new therapeutic strategies for AD.

Comparison of oxidative stress under different propofol administration protocols in Thoroughbred racehorses by bOS and bAP assessment

It is desirable to reduce surgery-induced oxidative stress (OS) because it can cause immune suppression and delayed wound healing. Propofol is known to have antioxidant potential and to reduce OS in humans, but there have been no studies of this issue in horses. This study was conducted to evaluate OS under three different propofol administration protocols in Thoroughbred racehorses undergoing arthroscopic surgery with sevoflurane anesthesia. Blood oxidative stress (bOS) and blood antioxidant power (bAP) were used as OS biomarkers. Both bOS and bAP significantly decreased after surgery in all groups, but no differences in these reductions were found among them. Different propofol administration protocols with sevoflurane anesthesia did not cause a difference in OS in Thoroughbred racehorses that underwent arthroscopic surgery.

A comparison of the effects of midazolam, propofol and dexmedetomidine on the antioxidant system: A randomized trial

Previous studies on the antioxidant activity of sedatives have predominantly been in vitro investigations that are lacking clinical data, resulting in conclusion without cogency. The aim of the present prospective, randomized study was to use single sedative drugs for anesthesia induction to compare their antioxidant properties. The effects on the antioxidant system of midazolam, propofol and dexmedetomidine were assessed using oxidative stress indicators and micronuclei (MN). Forty-nine patients undergoing esophageal cancer radical prostatectomy were selected. Midazolam, propofol and dexmedetomidine were used to induce anesthesia. Venous blood samples were obtained prior to and at 2 and at 24 h after surgery, and oxidative stress indicators were detected using the appropriate kits. The cytokinesis-block micronucleus cytome assay was executed and the frequencies of MN, nucleoplasmic bridges and nuclear buds were examined. It was found that the use of the three sedatives, respectively, led to a marked increase in the levels of free radical indicators at 2 h after surgery, which then decreased at 24 h after surgery. Furthermore, lower levels of oxidative stress were found following the use of propofol and dexmedetomidine compared with those following midazolam administration, and similar results were obtained regarding the level of MN. It is suggested that propofol and dexmedetomidine exhibit a superior antioxidant function to midazolam.