If you have ever interacted with a drunk, you may have noticed that his or her brain functions were somewhat impaired. Fortunately, most of the effects from drinking wear off with time, but permanent neurological damage can take place with excessive or chronic ethanol abuse. In particular, alcohol causes oxidative stress on the brain—it increases the levels of reactive oxygen species like peroxides and free radicals, which harm everything from DNA to proteins. At the same time, alcohol slows down naturally occurring antioxidant activity in the brain.
To limit oxidative damage, it makes sense to use powerful antioxidants from outside sources. Anup Srivastava from the University of Alabama at Birmingham and his colleague T. Shivanandappa knew from experience that the roots of Decalepis hamiltonii, a plant commonly used as folk medicine in southern India, are rich in biologically active antioxidants. Thus, they hypothesized that these tuberous roots could shield people from the neural damage of ethanol consumption.
Srivastava and Shivanandappa fed a group of rats extracts from Decalepis hamiltonii roots for seven consecutive days and then gave them ethanol (at a dosage of 5 g per kg of body weight) on the seventh day. After waiting 16 hours for the animals to process the alcohol, they sacrificed the rats and removed their brains for analysis. They also took the brains from two other groups for comparison. One group received alcohol on the seventh day, but did not get root extracts. The third group was used as a control; those rats got neither alcohol nor extracts.
The brains from the three groups of rats showed significant differences in levels of tissue damage and activities of key enzymes. Alcohol is known to degrade lipids and oxidize proteins, so it was no surprise that there were high levels of lipid and protein damage in the brains of untreated, ethanol fed rats. However, rats that ate Decalepis hamiltonii root extracts showed normal levels of lipid and protein degradation. Untreated, alcohol-fed rats also displayed depletions of detoxification enzymes like glutathione-S-transferase and antioxidant enzymes such as catalase, superoxide dismutase, glutathione peroxidase, and glutathione reductase. Treated rats were spared from those harmful effects.
In some cases, Decalepis hamiltonii root left the brain activities of alcohol fed rats in better shape than the control group. Treated rats had increased levels of detoxification and antioxidant enzymes, which further indicates that the extracts have neural protective properties and are potent antioxidants.
While Decalepis hamiltonii roots save the brain from some of the negative effects of alcohol intake, it has not been shown to protect other organs, like the liver. It also won’t prevent drunkenness and any embarrassing behavior that may occur as a result, so it can’t be used as a preparation to overindulge.
The most important results from this study really have little to do with alcohol. The fact that that Decalepis hamiltonii root extracts protect the brain from oxidative damage and have many active antioxidants could be useful for treating and preventing neurological damage from aging or diseases like Alzheimer’s and Parkinson’s. If scientists can determine how these extracts are guarding the brain and isolate the active chemicals from the roots, they might be able to design drugs to remedy a wide range of ailments.
Food Chemistry, DOI: 10.1016/j.foodchem.2009.07.003