Scientists at the University of Bonn have identified a substance that appears to be partly responsible for the previously unexplained sedative effect of valerian, a herbal native to Europe and used for more than 2,000 years.The researchers say that a lignan in valerian latches on to specific receptors in the brain which control the body’s sleeping and waking rhythms. Caffeine affects the same type of receptor but has the opposite effect, according to the team. They are now trying to copy a simplified version of the substance chemically to increase its efficacy.
