Hypermethioninemia is an inherited metabolic disorder characterized by high concentration of
methionine (Met) and its metabolites such as
methionine sulfoxide (Met-SO), which may lead to development of neurological alterations. The aim of this study was to investigate the in vitro effects of Met or Met-SO on viability, proliferation, morphology, and neurochemical parameters in primary culture of cortical astrocytes,
after treatment with 1 or 2 mM Met or 0.5 mM Met-SO, for 24, 48, and 72 h. Met or Met-SO did not affect cell viability and proliferation but induced astrocyte
hypertrophy.
Acetylcholinesterase activity was increased, while Na+, K+-
ATPase activity was decreased by 2 mM
Met, Met-SO, or Met (1 and 2 mM) + Met-SO (P < 0.05).
ATP and
AMP hydrolysis was decreased by Met (1 and 2 mM), Met-SO and Met (1 and 2 mM) + Met-SO treatment, while
ADP hydrolysis was enhanced by Met-SO and Met (1 and 2 mM) + Met-SO (P < 0.05).
Superoxide dismutase activity was increased by Met-SO and Met (1 and 2 mM) + Met-SO (P < 0.05).
Catalase and
glutathione S-transferase activities were reduced by Met or Met-SO treatment for 48 and 72 h (P < 0.05).
Reactive oxygen species and total
thiol content was reduced by Met or Met-SO treatment for 24, 48, and 72 h while
nitrite and
thiobarbituric acid reactive substance levels were increased under the same experimental conditions (P < 0.05). High concentrations of Met and Met-SO do not cause cell death but induced changes in astrocyte function. These alterations in astrocytic homeostasis may be associated with neurological symptoms found in
hypermethioninemia.