Publications

ABSTRACT Ergothioneine (ET) is a naturally occurring thiol/thione that possesses several cytoprotective properties. Multiple studies suggest a potential neuroprotective role for ET. Here, we show in various Parkinson's disease (PD) models that ET is indeed neuroprotective. Firstly, using Drosophila genetic PD models, we demonstrated that ET treatment ameliorates the pathological phenotypes of parkin and LRRK2 PD mutant flies. This includes an improvement in their climbing score and the preservation of their dopaminergic neuronal number and mitochondrial integrity. Similarly, we observed the rescue of PD phenotypes by ET in mice treated with the Parkinsonian neurotoxin 6‐OHDA. This protective effect of ET is abolished in mice lacking OCTN1. Finally, we found that ET protects human LRRK2‐G2019S patient‐derived dopaminergic neurons from rotenone‐induced neurotoxicity; the action of ET is again OCTN1‐dependent. Collectively, our results strongly support a neuroprotective role for ET in PD and suggest that ET may be useful in the prevention and/or treatment of PD. image

Many products of lipid oxidation have been associated with human diseases. These include F2 -isoprostanes (F2-IsoPs), hydroxyeicosatetraenoic acid products (HETEs), and cholesterol oxidation products (COPs). Here we present measurements of F2-IsoPs, HETEs, COPs, and arachidonate in single plasma samples of patients with acute (dengue fever and ischemic stroke) and chronic (Parkinson's) diseases, and in age-matched study controls. Urine samples were collected for F2-IsoPs analysis. Our analysis demonstrated elevated F2-IsoPs levels in ischemic stroke, HETEs in Parkinson's disease, dengue fever, and ischemic stroke, and COPs in Parkinson's disease and dengue fever patients, as compared with those in age-matched study controls. Strong but complex correlations were observed between levels of certain oxidized lipid products and age. The relations between various oxidized lipids and dengue fever, stroke, and Parkinson's disease are discussed in relation to the selection and application of biomarkers of oxidative lipid damage, in particular the need for corrections for age and lipid levels.

Positive genotoxicity results are often observed using mammalian cells in culture with agents that are not in vivo genotoxins. We here illustrate one possible explanation: interaction of test chemicals with the cell-culture media used. We find that the toxicity and clastogenicity of epigallocatechin gallate (EGCG) to Chinese Hamster ovary (CHO) cells is affected by the culture medium used and appears largely or entirely due to variable rates of formation of hydrogen peroxide (H2O2) by chemical reactions of EGCG with the culture media. Catalase decreased EGCG toxicity substantially. Of seven different types of commonly used media evaluated, F-10 and F-12 nutrient mixtures were the least prone to produce this artefact. Although it generated H2O2 in the culture media, ascorbate was not toxic to CHO cells because the H2O2 levels achieved were insufficient to kill these cells. Thus, the culture medium, the cell type and the presence or absence of catalase (e.g. its variable amounts in S9 fractions) must be taken into account in in vitro genotoxicity testing.