Researchers have discovered how a Chinese herbal tea remedy for jaundice works at a molecular level, opening up new avenues for drug development.
Jaundice is caused by the accumulation of the bile pigment bilirubin, leading to yellowing of the skin and whites of the eyes. The condition is extremely common in newborn infants owing to inadequate functioning of the liver, which normally removes bilirubin from the bloodstream.
In Western nations neonatal jaundice is usually treated by exposure to ultraviolet light, which helps to break down bilirubin in the skin. But in Asia the herbal remedy Yin Zhi Huang (YZH), a tea made of four different plants including Artemisia capillaris, has been used for centuries to prevent and treat neonatal jaundice.
Writing in last week's Journal of Clinical Investigation, a research team based at Baylor College of Medicine in Houston, United States, reports that YZH works by interacting with a liver receptor involved in the breakdown of bilirubin. Furthermore, they have tracked the effect of YZH down to a single active component: 6,7-dimethylesculetin.
"This is a wonderful example of knowledge gained by applying the Western scientific method to an Eastern herbal remedy," writes Mitchell A. Lazar, an endocrinologist at the University of Pennsylvania, United States, in a related perspective article.
Many Western medicine practitioners view the therapeutic use of such herbal concoctions with scepticism, as their effects on biochemical pathways are often unknown. But the researchers are optimistic that their discovery might prompt research into this particular mechanism for the development of new drugs to treat neonatal, genetic or acquired forms of jaundice.
"It will be very exciting if a pure compound emerges from the tea leaves as a pharmacological therapy for neonatal jaundice that is complementary or alternative to the current Western practice of phototherapy," adds Lazar.