Rachel Kogan ‘19

Many plant species that are accidentally transported from one continent to the other by humans become invasive species. The Giant Hogweed, Heracleum mantegazzianum,is one such species. The plant, originally found in the Caucasus Mountains in central Asia, has recently spread throughout Canada and the United States’ Northeastern region. Recently, scientists discovered the hogweed in Virginia, following reports of unusual burns associated with its contact.

According to the team of researchers led by Jordan Metzgar of the Massey Herbarium at Virginia Polytech Institute, H. mantegazzianum releases a unique sap that can be activated by sunlight. The sap contains a molecule known as furocoumarin, which when contacted by the sun’s ultraviolet light, changes its structure and binds strongly to thymine and cytosine in DNA. As a result, the cell is unable to replicate DNA or transcribe RNA and undergoes apoptosis, or programed cell death. The resulting sloughing off of dead cells causes burns and extreme skin pealing known as phytophotodermatitis. The researchers warned that H. mantegazzianum sap in the eyes can cause blindness.

Although it is difficult to treat phytophotodermatitis, there are methods of preventing it. If an individual comes in contact with the giant hogweed, researchers suggest washing the affected area immediately with soap and water for a prolonged time. Additionally, these areas should be covered from the sun until the water is reached in order to prevent the sap’s photoactivation. With these methods in mind, it is possible for individuals to combat the invasive species’ stinging burns as the plant becomes increasingly common in the United States.

References

1. D. Ackerman. Invasive Giant Hogweed’s Solar-Activated Sap Causes Blistering Skin Burns. Scientific American 119 (2018).  
2. Image retrieved from: http://www.geograph.ie/photo/1372690