Alteration of the Enantioselective Toxicity of Diclofop Acid by Nonylphenol: Effect on Ascorbate-Glutathione Cycle in Microcystis Aeruginosa

Capillary Blood GSH Level Monitoring, Using an Electrochemical Method Adapted for Micro Volumes

Glutathione (γ-glutamyl-cysteinyl-glycine; also known as GSH) is an endogenous antioxidant that plays a crucial role in cell defense mechanisms against oxidative stress. It is thus not surprising that this molecule can serve as a biomarker for oxidative stress monitoring. As capillary blood is a highly accessible target for biomarking, it is a valuable bodily fluid for diagnosing human GSH levels. This study focused on the optimization of GSH measurements from micro volumes of capillary blood prior to using electrochemical detection. The optimization of experimental parameters, including the sample volume and its stability, was performed and evaluated. Moreover, we tested the optimized method as part of a short-term study. The study consisted of examining 10 subjects within 96 h of their consumption of high amounts of antioxidants, attained from a daily dose of 2 g/150 mL of green tea. The subjects' capillary blood (5 μL) was taken at 0 h, 48 h, and 96 h for subsequent analysis. The short-term supplementation of diet with green tea showed an increase of GSH pool by approximately 38% (between 0 and 48 h) within all subjects.

Effects of glyphosate at environmentally relevant concentrations on the growth of and microcystin production by Microcystis aeruginosa

The use of glyphosate, which is a well-known sterilant herbicide, has been growing rapidly because the area under the cultivation of genetically modified crops that are tolerant to this herbicide has increased. Glyphosate can enter into aquatic systems through many different ways. However, information on the potential risks of glyphosate at environmentally relevant levels to aquatic systems is still limited. In this study, we selected the cyanobacterium Microcystis aeruginosa FACHB-905 (M. aeruginosa) as a model organism to evaluate the effects of glyphosate at environmentally relevant concentrations on the former's growth and microcystin (MC) production. Our results show that low levels of glyphosate stimulate the growth of M. aeruginosa. Subsequently, there was significant increase in the total MC-LR and intracellular MC-LR, but not in extracellular MC-LR, after exposure to 0.1-2 mg/L of glyphosate. The increase in total MC-LR is mainly due to the effects of glyphosate on the cell density of M. aeruginosa. The data provided here show that low level of glyphosate in a water body is a potential environmental risk factor that stimulates the growth and enhances MC production in M. aeruginosa, which should arouse great concern.