Hops have long been used in Chinese medicine to prevent and treat various ailments, from tuberculosis to heart disease to cancer. Recently, data from scientists at Lanzhou University support a role for hops in protecting the brain from neurodegenerative diseases like Alzheimer’s and Parkinson’s.
The Lanzhou scientists – Juan Yao, Baoxin Zhang, Chunpo Ge, Shoujiao Peng, and Jianguo Feng – identified oxidative stress as a primary cause of neurodegeneration, because neurons are particularly vulnerable to “free radicals” – atoms (or groups of atoms) that have an odd number electrons and are formed when oxygen interacts with certain molecules. Free radicals create the most damage when they form chain reactions and react with cellular DNA or cell membranes, often killing the cell. Cell death has more impact in the brain since neurons have limited replenishment over the human lifetime compared to other cell types. However, this process occurs throughout the body and is the reason why “antioxidants” – molecules that block activity of free radicals – are so trendy.
Yao et al. hypothesized that Xanthohumol (“Xn”), a compound in hops that has already been studied for various pharmacological properties, may protect neurons from oxidative damage. They isolated Xn and tested its effects against oxidative-stress-induced neural cell damage in a particular line of rat cells (PC12). The data showed not only that Xn may itself attack free radicals, but also that it activates a transcription factor (a protein that helps make DNA from RNA, thus regulating gene expression, contributing to cellular processes such as development and communication) called Nrf2 in the rat cells. Nrf2 in turn increases activity of cytoprotective genes, and correspondingly, availability of their antioxidant gene products, including glutathione, heme oxygenase, NAD(P)H:quinone oxidoreductase, thioredoxin, and thioredoxin reductase. This activity by Xn provided a protective benefit for the cells against free radicals and their negative oxidative effects.
The scientists state that the data show the first demonstration of this mechanism underlying the neuroprotective action of Xn. While it’s not clear that the hops in a pint of beer a day will supply sufficient Xn to protect your neurons, the study suggests that Xn is a good pharmacological candidate for prevention of neurodegenerative disorders like Alzheimer’s and Parkinson’s.
Yao J, Zhang B, Ge C, Peng S, Fang J. Xanthohumol, a Polyphenol Chalcone Present in Hops, Activating Nrf2 Enzymes To Confer Protection against Oxidative Damage in PC12 Cells. Journal of Agriculture and Food Chemistry. 2015.