Magnesium may help protect retinal cells from the harmful calcium overload that can damage them, according to computer simulations by scientists from Poland, Germany and Iran. However, the simulations show that the protective effect depends on the magnesium concentration and on how early it is introduced.
Retinal ganglion cells transmit visual information from the eye to the brain. Their death causes permanent vision loss and occurs in conditions including glaucoma, retinal ischaemia, diabetic retinopathy and optic nerve injuries.
Glaucoma affects more than 70 million people worldwide. One mechanism of retinal cell damage involves an excess of glutamate, which overstimulates receptors and allows harmful amounts of calcium ions to enter the cells.
‘Retinal ganglion cells serve as the eye's output channels. Our model shows that magnesium can limit dangerous calcium overload without completely cutting off information transmission. Finding a balance between protection and maintaining function was our top priority’, says Mehdi Borjkhani, PhD, from the International Centre for Translational Eye Research (ICTER) at the Institute of Physical Chemistry of the Polish Academy of Sciences, as quoted in the institute's press release.
The researchers developed a digital model of a single retinal ganglion cell. In their simulations, the cell was exposed to glutamate pulses at different frequencies.
Frequencies of 10 to 60 Hz represented normal, healthy eye function, while 80 to 100 Hz were used to model the intense, prolonged stress associated with disease progression.
Under these stress conditions, magnesium helped block the influx of calcium ions. The simulations allowed the researchers to calculate a range of magnesium concentrations that reduced calcium levels below the toxicity threshold during severe stress.
Within this range, the cell retained the ability to transmit 80 percent of its signals.
‘Below this range, the protection was too weak; above it, function suffered too much’, Mehdi Borjkhani says.
The timing of the magnesium increase was also important. The simulations showed that the greatest protection occurred when magnesium concentration was increased before the cell accumulated approximately 35 percent of the maximum toxic calcium load.
The study is based entirely on computer modelling and does not constitute a ready-made therapy or recommendation for home supplementation. The results provide a framework for further testing in tissues and clinical trials.
The study concept was developed by Mehdi Borjkhani of ICTER, who led the project. The team also included Hadi Borjkhani from HTW Berlin and Morteza A. Sharif from Urmia University of Technology in Iran.
The findings were published in PLOS One.
PAP - Science in Poland
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