Blue Food Dye Shown to Speed Healing of Spinal Cord Injuries in Rats

Researchers have stumbled upon a surprise possible treatment for swelling of nerves in the spinal cord. It turns out that FD&C blue dye No. 1 bears certain key similarities to a compound used to treat nerve inflammation. Since there is no active immediate treatment for spinal cord injuries, and secondary inflammation often leads to long-term damage, this treatment holds great promise. The one side-effect observed: the rats’ skin turned blue.

According to Wired:

In 2004, [neuroscientist Maiken Nedergaard of the University of Rochester Medical Center] and colleagues discovered that swelling around the cord is caused by the rapid release of ATP, the molecule that normally provides energy for the cell. Excessive amounts of ATP overstimulate nerve cells and cause them to die of metabolic stress. The researchers found that blocking an ATP receptor called P2X7 prevented much of the inflammation associated with spinal cord injury. But until now, they hadn’t identified a clinically useful drug that could block the receptor.

“We just had proof of principle,” Nedergaard said. “We didn’t have anything we could give to patients.” Then, while searching for chemicals with structures similar to the P2X7 receptor, the scientists came across FD&C blue dye No. 1, completely non-toxic and approved by the FDA in 1928.

The huge amount of blue dye consumed by Americans every year —100 million pounds in total— is an effective demonstration of the chemical’s non-toxicity. It has also been demonstrated that the substance is able to transfer across the blood-brain barrier, making it possible to treat nerve inflammation without a direct spinal injection, which could present added risks to patients already suffering injury to the spinal cord.

Wired reports that “Animals who received the blue dye recovered much faster than animals who didn’t: By six weeks, the treatment group could walk with a limp, while the no-treatment group never recovered the ability to walk.” That result came when the treatment was given within 15 minutes of a weight falling on the rats’ backs (under anesthesia). The 15-minute treatment time-frame is a problem, because most human victims of spinal cord injury are not able to receive diagnosis and treatment so quickly.

Further testing may be attempted, to see if there may be positive effects in treatment delivered long after injury. With such a dramatic difference in outcome —six weeks to walking as opposed to never walking again—, the discovery of blue dye’s anti-inflammatory properties will result in some innovation in the spinal cord injury treatment regime, which is, at present, desperately in need of reliable options.

The effectiveness of blue food dye in treating inflammation in such delicate tissue as spinal cord nerve cells could translate into broader anti-inflammatory uses for the active chemical, but such studies have not yet been conducted. The focus will remain on the most effective gain over standard current practice, a direct, targeted treatment for reducing inflammation in spinal cord tissue. A first step will be to try to reduce the bluing effect of the treatment. Further research may change the way inflammatory injuries are understood broadly.

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