[Cytotoxicity of Malondialdehyde and Cytoprotective Effects of Taurine via Oxidative Stress and PGC-1α Signal Pathway in C2C12 Cells]

Baicalin Attenuates Oxidative Stress in a Tissue-Engineered Liver Model of NAFLD by Scavenging Reactive Oxygen Species

Oxidative stress plays an important role in the pathogenesis of nonalcoholic fatty liver disease (NAFLD). Baicalin has been shown to exert protective effects in various liver diseases. The mechanism of baicalin's antioxidative effect in NAFLD is currently unclear. The aim of this study was to investigate the effects and mechanisms of baicalin on oxidative stress in a new tissue-engineered liver model of NAFLD. The 3D model of NAFLD was induced by a fat-supplemented medium (fatty acids, FFA group) for 8 days and baicalin was administered on the 5th day. CCK-8 assay showed that baicalin at concentrations below 100 μM had no obvious cytotoxicity. Baicalin inhibited apoptosis and lactate dehydrogenase release in the FFA group. Baicalin reduced the levels of reactive oxygen species and malondialdehyde induced by FFA, and increased superoxide dismutase and glutathione amounts. However, it did not upregulate nuclear erythroid 2-related factor 2 compared with the FFA group. Mitochondrial morphology was partially restored after baicalin treatment, and ATP5A expression and mitochondrial membrane potential were increased. The superoxide anion scavenging ability of baicalin was enhanced in a dose-dependent manner. In summary, baicalin reduces oxidative stress and protects the mitochondria to inhibit apoptosis in the 3D NAFLD model via its own antioxidant activity.

Taurine as a Natural Antioxidant: From Direct Antioxidant Effects to Protective Action in Various Toxicological Models

Natural antioxidants have received tremendous attention over the last 3 decades. At the same time, the attitude to free radicals is slowly changing, and their signalling role in adaptation to stress has recently received a lot of attention. Among many different antioxidants in the body, taurine (Tau), a sulphur-containing non-proteinogenic β-amino acid, is shown to have a special place as an important natural modulator of the antioxidant defence networks. Indeed, Tau is synthesised in most mammals and birds, and the Tau requirement is met by both synthesis and food/feed supply. From the analysis of recent data, it could be concluded that the direct antioxidant effect of Tau due to scavenging free radicals is limited and could be expected only in a few mammalian/avian tissues (e.g., heart and eye) with comparatively high (>15-20 mM) Tau concentrations. The stabilising effects of Tau on mitochondria, a prime site of free radical formation, are characterised and deserve more attention. Tau deficiency has been shown to compromise the electron transport chain in mitochondria and significantly increase free radical production. It seems likely that by maintaining the optimal Tau status of mitochondria, it is possible to control free radical production. Tau's antioxidant protective action is of great importance in various stress conditions in human life, and is related to commercial animal and poultry production. In various in vitro and in vivo toxicological models, Tau showed AO protective effects. The membrane-stabilizing effects, inhibiting effects on ROS-producing enzymes, as well as the indirect AO effects of Tau via redox balance maintenance associated with the modulation of various transcription factors (e.g., Nrf2 and NF-κB) and vitagenes could also contribute to its protective action in stress conditions, and thus deserve more attention.

Pro-inflammatory Mediators and Oxidative Stress: Therapeutic Markers for Recurrent Angina Pectoris after Coronary Artery Stenting in Elderly Patients

BACKGROUND

Pro-inflammatory mediators and oxidative stress are related to severity of angina pectoris in patients with coronary heart disease.

OBJECTIVE

We evaluated the effects of pro-inflammatory mediators and oxidative stress on recurrent angina pectoris after coronary artery stenting in elderly patients.

METHODS

We determined the expression levels of malondialdehyde (MDA), acrolein (ACR), tumour necrosis factor-α (TNF-α), toll-like receptor 4 (TLR4), superoxide dismutase 3 (SOD3), paraoxonase-1 (PON-1), stromal cell-derived factor-1α (SDF-1α) and endothelial progenitor cells (EPCs) in elderly patients with recurrent angina pectoris after coronary artery stenting.

RESULTS

Levels of MDA, ACR, TNF-α and TLR4 were significantly increased (p<0.001), and levels of SOD3, PON-1, SDF-1α and EPCs were significantly decreased (p<0.001) in the elderly patients with recurrent angina pectoris after coronary artery stenting. MDA, ACR, TNF-α and TLR4 as markers of oxidative stress and pro-inflammatory mediators may have suppressed SOD3, PON-1, SDF-1α and EPCs as markers of anti-oxidative stress/anti-inflammatory responses. Oxidative stress and pro-inflammatory mediators were important factors involved in recurrent angina pectoris of elderly patients after coronary artery stenting.

CONCLUSION

Oxidative stress and pro-inflammatory mediators could be considered as potential non-invasive prognostic, predictive and therapeutic biomarkers for stable recurrent angina and recurrent unstable angina in the elderly patients after coronary artery stenting.