Toxic gas might help reduce damage after heart attacks

Associate+Professor+Ming+Xian+%28right%29+speaks+with+Tyler+Biggs%2C+second+year+graduate+student%2C+in+his+lab+in+Fulmer+Hall%2C+Tuesday%2C+April+1.

Associate Professor Ming Xian (right) speaks with Tyler Biggs, second year graduate student, in his lab in Fulmer Hall, Tuesday, April 1.

Hydrogen sulfide gas is considered toxic to humans, but a WSU researcher is developing a method that uses it to treat heart attacks.

Ming Xian, an associate professor in the chemistry department, is developing a treatment that targets reactive oxygen species (ROS) created by heart tissue during heart attacks. Xian said ROS are the substances responsible for the damaging effects of heart attacks, and hydrogen sulfide (H2S) acts as a “scavenger” that effectively mitigates their damaging effects.

Kerry Hipps, department of chemistry chair, explained that during a heart attack, a clogged artery blocks the flow of oxygen to the heart. Hipps said a dose of hydrogen sulfide might limit damage by reducing the amount of oxygen the heart and body need.

Damage can also occur when circulation is restored after a heart attack, causing a large and sudden influx of oxygen.

Xian and other researchers have found that hydrogen sulfide limited tissue damage in mice that experienced induced heart attacks. He noted that the human body produces the substance in small concentrations, but it is unstable and can harm healthy cells.

“It’s almost impossible to control,” he said. “The gas molecule would go everywhere. By using our H2S donor we could make those stable compounds and use a lot of chemical techniques to make them deliverable…that’s why we have to solve the problem and why we are doing this.”

To limit damage, Xian has collaborated with other researchers to prepare a more stable, aqueous solution that can be controlled more effectively. He said the most important challenge is to control the spread of the substance so that it reaches only the intended area of one’s body.

“The value of our work is to provide people with this very unique research tool of H2S donors,” he said. “If they directly use H2S gas, it’s difficult to control the concentration. If it’s difficult to control the concentration, then they could make wrong interpretations.”

The pharmaceutical and therapeutic effects of hydrogen sulfide might make it a viable option for treating diabetes, Alzheimer’s disease, Parkinson’s disease and cancer, Xian said. He said researchers have found lower concentrations of the substance in the brains of mice with Parkinson’s than in those of healthy mice.

Xian said more research must be done to limit the harmful effects of the substance during treatment. So far, no clinical testing has been performed on human subjects.

“There’s lots of places it could go, but the science that enables actually using it as a drug has not been done yet,” said Brian Kraft, the assistant director of business development for the College of Arts and Sciences. “The idea of having it in a chemical that releases hydrogen sulfide in a definable way is something that’s never been done. That level of control is really important.”

Xian said he has constructed molecules that, when introduced into a biological system, react in a specific way to release hydrogen sulfide. In other words, he has built the chemical platforms for future drugs. He and Kraft are working with chemical suppliers to sell compounds that can help detect hydrogen sulfide.

“(Xian’s) research with hydrogen sulfide is viewed by other researchers all across the country and across the world as being important,” Hipps said, commending Xian for his dedication to science and 60-hour weeks of research.

Xian conducts his research using a $300,000 award from the American Chemical Society and $1.5 million from the National Institutes of Health.