Beer Brews Up Good Medicine for the Brain

A glass of red wine a day could be just what the doctor ordered, but does that leave beer drinkers behind? Not according to a recent study published by researchers at Lanzhou University in China. The scientists studied the concept that beer, too, may provide health benefits, specifically for neurological conditions, and could protect neurons from oxidative stress.

Led by first author Juan Yao, the investigators studied the compound xanthohumol (2′,4′,4-trihydroxy-6′-methoxy-3′-prenylchalcone), a molecule derived from hops, a key beer ingredient. According to the article, xanthohumol “has received increasing attention due to its multiple pharmacological activities. As an active component in beers, its presence has been suggested to be linked to the epidemiological observation of the beneficial effect of regular beer drinking.” The main source of xanthohumol in the human diet apparently is beer.

The scientists synthesized xanthohumol in the lab and tested it on PC12 cells to determine whether the beer-derived compound was neuroprotective against oxidative stress. PC12 cells, a frequently used research tool, are a cell line derived from pheochromocytoma of rat adrenal medulla. They are neuron-like but also divide, making them easy to grow in the lab. They can be used as a first step to study neurological conditions.

Oxidative stress occurs in many disorders of the brain, such as Alzheimer disease (AD) and Parkinson disease (PD), and in several other diseases, such as cancer. In vitro, xanthohumol has indeed been observed to prevent the formation of cancerous cells.

The researchers found that not only did xanthohumol reduce oxidative stress–induced PC12 cell death, it also increased the cells’ production of antioxidants. It appeared to do this by upregulating several neuroprotective genes and gene products. The antioxidant molecules that increased included glutathione, heme oxygenase, NAD(P)H:quinone oxidoreductase, thioredoxin, and thioredoxin reductase. Their production was determined to be dependent on xanthohumol’s activation of the Nrf2 transcription factor, a previously unrecognized target of xanthohumol.

Known to be present in a latent form in all cells, Nrf2 is activated in the presence of free radicals, where it acts as a master regulator of antioxidants.

Yao and colleagues concluded, “Our results demonstrate that [xanthohumol] is a novel small-molecule activator of Nrf2 in neuronal cells and suggest that [xanthohumol] might be a potential candidate for the prevention of neurodegenerative disorders.” To determine whether xanthohumol can protect brain cells, additional studies in animal models of neurodegenerative disease are needed, as well as studies in humans.

Aside from the study making beer-lovers and brewers happy, the work has implications for treatment of neurological conditions. Additional research of the compound xanthohumol might point toward preventative measures for AD, PD, or even other neurodegenerative conditions.

The article appeared on January 28, 2015, in the Journal of Agricutural and Food Chemistry, published by The American Chemical Society.

Take-aways:

• Xanthohumol found in beer may protect against oxidative stress, which occurs in many disorders of the brain, such as AD and PD.

• An in vitro study demonstrated neuronal protection via xanthohumol, which appears to work via activation of Nrf2, an antioxidant regulator.

• Additional research might point toward preventative measures for AD, PD, or other neurodegenerative conditions.

References:

1. Yao J, Zhang B, Ge C, et al. Xanthohumol, a polyphenol chalcone present in hops, activating Nrf2 enzymes to confer protection against oxidative damage in PC12 cells. J Agric Food Chem. 2015 Jan 28. [Epub ahead of print]