Scientists are convinced that they may have already found a new form of painkillers that give relief from pain like morphine without the fatal side effects and will not cause addiction.
Nobody believed it was possible. However, a scientist named Dr. Laura Bohn from Stanford University found a protein called beta-arrestin, which sticks to the opioid receptor when activated by something like morphine. Dr. Bohn tried giving morphine to mice that was not capable of making beta-arrestin. She found that the mice had the numbing effect to pain, but most of the negative side effects of the drug were absent.
She said the mice didn’t build tolerance to the drug, and when given at different dosages, they had less withdrawal. She also found that the animals’ breathing was regular, and they were not as constipated as other mice on morphine.
Before the experiment, npr.org reported that scientists thought the mu-opioid receptor was just a simple switch that switched all the effects of opioids on or off all at once. . “The hope is you’d have another molecule that looks like morphine and binds to the same receptor, but the way it turns the receptor on is slightly different,” says Dr. Aashish Manglik, a researcher at Stanford University School of Medicine who studies opioid receptors.
After the discovery, a number of people, including a team that includes Manglik, started to look for a drug to connect the mu-opioid that will avoid the negative effects of beta-arrestin. They traced the receptor’s structure in a program and started searching for chemicals that would adhere to it. “We tried to look for molecules that would still bind to this 3-D structure, but are as far away from morphine and codeine as possible,” Manglik says.
Among the 3 million possible chemicals they tested, the team picked the 23 best candidates to be tested in the lab. After a series of tests, a chemical called PZM21, seemed to do what they were hoping for. The chemical turned the opioid receptor on without using much beta-arrestin. Their findings were published in the journal Nature, wbur.org reported.
The team then adjusted the chemical to make it more powerful and gave it to mice. There was a reduction in the pain felt by mice similar to that when morphine was used. However, the mice appeared to have a much normal breathing pattern and didn’t appear to be high.
“If you give a mouse a drug that activates its reward pathways like cocaine, amphetamine or morphine, the mice just run around more. In this compound, we saw very little of that,” Manglik says. The mice also didn’t seem to have a preference between the chemical and salt water, independent.co.uk reported.
This simply means that the compound is less dangerous and has less potential for abuse compared to something like morphine, but may still be an effective painkiller. So far, the compound has only been tested in mice, but the scientists are hoping that it would work with humans the same way it did with mice.