Sickle-cell disease is a blood disorder that affects tens of thousands of Americans and millions worldwide. A modified form of vanilla may someday help treat it.
Turning vanilla into a drug. I'm Bob Hirshon and this is Science Update.
Aside from flavoring cakes, cookies, and trendy new colas, vanilla has serious potential as a medicine. Scientists have long known that vanillin, the main flavor compound in vanilla, can fight a blood disease called sickle-cell anemia.
According to Toshio Asakura, a research hematologist at Children's Hospital of Philadelphia, the problem is that it works only in test tubes.
If you give the vanillin or vanilla to patients with sickle-cell disease, all vanillin is destroyed in the stomach, because we have enzymes to destroy vanillin.
So eating a pint of vanilla ice cream won't do a sickle-cell patient any good. But now, a San Diego company called Medinox has made a modified form of vanillin that resists digestion.
Dr. Asakura's team recently tested the compound in mice—with good results. He says it could be a promising alternative to hydroxurea, the only sickle-cell drug on the market.
Although hydroxurea is beneficial for many patients, some patients have strong side effects from hydroxurea, and cannot take it. My goal is to find a very safe and very effective new drug that can be used by all patients.
It's hoped that the vanilla-based drug will be just one of many. I'm Bob Hirshon for AAAS, the Science Society.
Making Sense of the Research
This study shows how much time can pass between the steps in a scientific discovery. It's been known for decades that vanillin has the potential to fight sickle-cell disease. But it took until now for someone to figure out how to get vanillin to work in the body.
Sickle-cell disease is caused by a malfunction in a protein called hemoglobin, which gives blood its red color. In a sickle-cell patient, the defective hemoglobin can cause a normally round red blood cell to collapse into a bent sickle shape. Unlike normal red blood cells, the bent sickle cells are too stiff to pass through capillaries and into smaller blood vessels. As a result, they clog and damage the blood vessels. The results can include severe pain, stroke, anemia, life-threatening infections, and damage to the lungs and other organs.
The modified version of vanillin described here, which has the catchy name MX-1520, is called a prodrug. A prodrug is a drug that turns into an active drug in the body. Dr. Asakura found that MX-1520 turns into vanillin in the mouse bloodstream. Once there, it binds to the defective hemoglobin and prevents sickle cells from forming. If you just fed the mouse vanilla cake frosting, on the other hand, the vanillin would be completely digested before it ever reached the bloodstream.
The chemical hasn't been tested in humans yet. Dr. Asakura guesses that if it works, patients would have to take the prodrug one to several times per day, because the vanillin would probably clear from the body after several hours. The first step in testing a new drug like this on people is to test for safety. Only after the drug is proven safe can additional experiments be approved to test its effectiveness. The good news is that vanillin itself is already known to be safe to eat, so there's a good chance that the prodrug will be safe too.
Now try and answer these questions:
- What is sickle-cell disease? How does vanillin help fight it?
- Why has vanillin not been used as a medicine?
- What is a prodrug? Why is it useful?
- Why is it important to keep looking for new treatments for a disease, even if an effective treatment already exists?