The year is 659 AD: the Central American city of Monte Alban already holds 30,000 people; the Indian mathematician Brahmagupta has introduced the use of negative numbers; Penda, the last heathen king of England, has just died in battle and an extract from the honeysuckle plant is considered an herbal remedy for releasing poisons from the body, reducing fever and as an expectorant. You could care less because you're currently living in China during the Tang dynasty, you've just spent the previous night drinking far too much yellow wine (first produced in about 2100 BCE) and you now have a hangover.
Fortunately, there is an extract from the oriental raisin tree, Hovenia dulcis, which has recently become popular among your fellow revelers as a remedy for many of your symptoms. Ironically, the fruits of this tree are not actually raisins, they just taste like them, and they often used to make wine, which presumably could also produce a hangover. One component of this extract, known as either ampelopsin or dihydromyricetin, may be able to protect the liver from various toxins (Hase et al., Biol & Pharmaceut Bull, 1997).
Recently, a group from UCLA (Shen et al., J Neurosci, 2012) published a study showing that rats given dihydromyricetin were significantly less vulnerable to the inebriating effects of alcohol. These rats were able to consume massive quantities of alcohol without passing out. Not only that, they demonstrated fewer indications of being hung over afterwards. Even more surprising after weeks of alcohol consumption the rats given this herbal extract failed to show the usual signs of alcohol addiction.
The UCLA researchers allowed a group of rats to consume the equivalent of about 20 beers in less than two hours. Needless to say, within a short period of time the rats had passed out and were completely unable to right themselves when placed on their backs. About one hour later the rats began to recover some simple motor skills and improved coordination.
A second group of rats were administered the dihydromyricetin and then allowed access to the same amount of alcohol. Overall, these extract-treated rats tolerated the alcohol far better. They required far more time to demonstrate the impaired motors skills that the same amount of alcohol induced in the first group of rats. In addition, their stupor lasted for a much shorter period of time; only about fifteen minutes. Two days later the symptoms of hangover, such as increased anxiety and susceptibility to seizures, were also much reduced by simultaneous treatment with the tree extract.
It gets better! The authors concluded that this extract might even prevent addiction. Most rats when offered free access to alcohol will continue to increase their daily consumption; in humans, we would call this becoming addicted. Rats administered the dihydromyricetin did not increase their daily consumption of alcohol. Essentially, they remained just social drinkers.
It is thought that dihydromyricetin is able to achieve these benefits by blocking the action of alcohol at its primary site of action in the brain, the GABA receptor. Therefore, this extract will not protect you from the negative peripheral consequences of binge drinking on the liver and other organs. Thus, this extract might one day be used to prevent hangovers or rescue people from alcohol poisoning, which is exactly what the extracts from this tree were once claimed to do in 659 AD.
© Gary L. Wenk, Ph.D. Author of Your Brain on Food (Oxford Univ Press)