What Is Radiation Sickness and Are There Drugs to Treat It?

Scientists from Tennessee recently said a drug they have been developing could treat radiation sickness, and they are working to raise the money to fulfill the last stage of requirements from the Food and Drug Administration (FDA).

Currently, there is no drug available to treat gastrointestinal radiation sickness, but a team of University of Tennessee researchers led by cell biologist and cancer researcher Dr. Gabor Tigyi and Professor Leonard Johnson said they are working on a drug that shows potential.

People develop radiation sickness after receiving a large dose of radiation over a short period of time, with the amount of radiation absorbed by the body determining the degree of illness, according to the Mayo Clinic. The disease is also known as Acute Radiation Syndrome (ARS) or radiation poisoning and can cause diarrhea, nausea and fatigue, with high levels of radiation fallout leading to death, often within a couple of weeks.

Since the first atomic bombings at the end of World War II, radiation sickness has largely been linked to accidents at nuclear power plants, such as the 1986 fire and explosion at the Chernobyl nuclear plant in Ukraine.

With the war in Ukraine escalating, a number of news outlets have reported that European and U.S. consumers were panic buying iodine and potassium iodide tablets in response to Russian President Vladimir Putin's threats to use nuclear weapons as his war with Ukraine extended into its second month.

Potassium iodide is absorbed by the thyroid gland. The right dose can saturate the thyroid gland, helping to block the radioactive iodine that is released by radiation fallout. However, according to the American Council on Science and Health, the compound is only effective at blocking one radiation-related illness—thyroid cancer. By contrast, until recently there have been no effective treatments for parts of the body, including the gastrointestinal tract, which are especially vulnerable to radiation exposure.

The team led by Tigyi and Johnson has focused their work on the gastrointestinal tract and on the body's mechanism for repairing the damage caused by high-energy radiation.

Ukraine Nuclear Disaster Tribute
Researchers in Tennessee have said they are working on the first-ever drug that could treat gastrointestinal radiation sickness, which would help victims of nuclear disasters, such as the one at Chernobyl in 1986. Pictured, employees of the Chernobyl nuclear power plant visit a memorial on April 2021, the 35th anniversary of the accident.

Focusing on repair

Radiation exposure affects the human body's main molecules, DNA, proteins, lipids and sugars, but the body has a highly efficient DNA damage repair mechanism, which is capable of protecting against changes in our DNA, Tigyi told Newsweek. His team has spent two decades investigating lysophosphatidic acid (LPA), which acts as a natural protective molecule in cells. The researchers discovered that LPA has the ability to boost DNA damage repair and cell regeneration pathways after exposure to radiation.

Yet when the LPA system is hijacked in aggressive tumor stem-like cells, this mechanism can also help cancer cells resist radiation-therapy induced cell death.

The drug that the team has developed, RX-100, aims to use both the beneficial and destructive tendencies of LPA, Tigyi says.

"The drug discovery efforts we have been undertaking are targeting at both sides," he added. "To exploit LPA-based drugs that humans can benefit from and other drugs to hit the cancer stem-cells on the head and prevent them from being able to use LPA for generating resistance, invasion, and evasion of tumor immunity."

The target of RX-100 is intestinal stem cells, which regenerate the intestinal lining, but can be hard to replace because of their location at the bottom of the gut. However, the drug candidates they have developed, when administered via a single jab, can reach these intestinal stem cells, protect them and promote the regeneration of the gut.

In addition to treating ARS, the drug has the potential to be used to combat other illnesses, Tigyi said, including blocking the toxin-inducing process responsible for the development of diarrhea in cholera. It also has the potential to fight clostridium difficile, a severe bacterial infection, by strengthening the gut barrier function.

RxBio Inc., the company that Tigyi founded, has already tested the drug's efficacy in rodents, but must show that it is safe and effective in an additional animal species, as trials using radiation can not include human beings. For this stage, the company is looking to raise around $170 million of additional funding.