Parkinson’s disease (PD) is a neurodegenerative disorder characterized by the gradual loss of midbrain dopaminergic neurons in association with aggregation of α-synuclein. Oxidative damage has been widely implicated in this disease, though the mechanisms involved remain elusive. Here, we demonstrated that preferential accumulation of peroxidized phospholipids and loss of the antioxidant enzyme glutathione peroxidase 4 (GPX4) were responsible for vulnerability of midbrain dopaminergic neurons and progressive motor dysfunctions in a mouse model of PD. We also established a mechanism wherein iron-induced dopamine oxidation modified GPX4, thereby rendering it amenable to degradation via the ubiquitin-proteasome pathway. In conclusion, this study unraveled what we believe to be a novel pathway for dopaminergic neuron degeneration during PD pathogenesis, driven by dopamine-induced loss of antioxidant GPX4 activity.

It is now well established that the developing embryo is very sensitive to oxidative stress, which is a contributing factor to pregnancy-related disorders. However, little is known about the effects of reactive oxygen species (ROS) on the embryonic cardiovascular system due to a lack of appropriate ROS control method in the placenta. In this study, a small molecule called 2,2-azobis(2-amidinopropane) dihydrochloride (AAPH), a free radicals generator, was used to study the effects of oxidative stress on the cardiovascular system during chick embryo development. When nine-day-old (stage HH 35) chick embryos were treated with different concentrations of AAPH inside the air chamber, it was established that the LD₅₀ value for AAPH was 10 µmol/egg. At this concentration, AAPH was found to significantly reduce the density of blood vessel plexus that was developed in the chorioallantoic membrane (CAM) of HH 35 chick embryos. Impacts of AAPH on younger embryos were also examined and discovered that it inhibited the development of vascular plexus on yolk sac in HH 18 embryos. AAPH also dramatically repressed the development of blood islands in HH 3+ embryos. These results implied that AAPH-induced oxidative stress could impair the whole developmental processes associated with vasculogenesis and angiogenesis. Furthermore, we observed heart enlargement in the HH 40 embryo following AAPH treatment, where the left ventricle and interventricular septum were found to be thickened in a dose-dependent manner due to myocardiac cell hypertrophy. In conclusion, oxidative stress, induced by AAPH, could lead to damage of the cardiovascular system in the developing chick embryo. The current study also provided a new developmental model, as an alternative for animal and cell models, for testing small molecules and drugs that have anti-oxidative activities.

Background: Lutein is an important eye-protective nutrient. This study investigates the protective effects and mechanisms of lutein on lipopolysaccharides (LPS)-induced uveitis in mice. Methods: Lutein, suspended in drinking water at a final concentration of 12.5 and 25 mg/mL, was administered to mice at 0.1 mL/10 g body weight for five consecutive days. Control and model group received drinking water only. Uveitis was induced by injecting LPS (100 mg per mouse) into the footpad in the model and lutein groups on day 5 after the last drug administration. Eyes of the mice were collected 24 hours after the LPS injection for the detection of indicators using commercial kits and reverse transcription-polymerase chain reaction. Results: LPS-induced uveitis was confirmed by significant pathological damage and increased the nitric oxide level in eye tissue of BALB/C mice 24 hours after the footpad injection. The elevated nitric oxide level was significantly reduced by oral administration of lutein (125 and 500 mg/kg/d for five days) before LPS injection. Moreover, lutein decreased the malondialdehyde content, increased the oxygen radical absorbance capacity level, glutathione, the vitamin C contents and total superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities. Lutein further increased expressions of copper-zinc SOD, manganese SOD and GPx mRNA. Conclusion The antioxidant properties of lutein contribute to the protection against LPS-induced uveitis, partially through the intervention of inflammation process.

Abstract:  The special flavor and health effects of chicken essence are being widely accepted by people. Scientific researches are revealing its truth as a tonic food in traditional health preservation. Chicken essence has been found to possess many bioactivities including relief of stress and fatigue, amelioration of anxiety, promotion of metabolisms and post‐partum lactation, improvement on hyperglycemia and hypertension, enhancement of immune, and so on. These activities of chicken essence are suggested to be related with its active components, including proteins, dipeptides (such as carnosine and anserine), polypeptides, minerals, trace elements, and multiple amino acids, and so on. Underlying mechanisms responsible for the bioactivities of chicken essence are mainly related with anti‐stress, anti‐oxidant, and neural regulation effects. However, the mechanisms are complicated and may be mediated via the combined actions of many active components, more than the action of 1 or 2 components alone.