Plant DNA Found in Medicines from Ancient Roman Shipwreck

DNA testing performed on more than 2,000-year-old tablets has confirmed what historians of pharmacy have known for some time—ancient Romans regarded plants as medicines.¹

The green tablets, sealed in tin containers from what is presumed to have been a medical kit, were found aboard the sunken ship Relitto del Pozzino, which was discovered off the coast of Italy, in the Gulf of Baratti, in 1974.^1,2

In the 1980s and ‘90s, a team from the Archaeological Superintendency of Tuscany partially excavated the shipwreck.² Underwater archaeologist Enrico Ciabatti told Discovery News that the Relitto probably met its watery grave as the result of a storm.² In 2004, fragments of the medicinal tablets were given to Alain Touwaide, PhD, founding member and scientific director of the Institute for the Preservation of Traditional Medicines, a nonprofit organization hosted by the Smithsonian Institution in Washington, DC.³

“When I knew about these tablets,” Dr. Touwaide said, “I did everything I could to get them. And it took such a long time—6 years—to get the results" (oral communication, November 30, 2010).

Originally circular, the fragments bestowed on Dr. Touwaide were approximately 1 inch in diameter and one-quarter of an inch thick, “We had two small fragments of one half-an-inch segment of the tablets,” said Dr. Touwaide. “Small, but enough to have good DNA material in it.”

According to Dr. Touwaide, the results from preliminary tests on the tablets shocked him, because these less-advanced analyses showed botanical ingredients not indigenous to the area. “We had plants which are more from central Asia or the Far East, and for me, it didn’t work... though [the Romans of this period] knew some plants from the Far East.”

The following DNA analysis of the tablets was performed by Robert Fleischer, PhD, who heads the Genetics Program at the Smithsonian Institution’s National Museum of Natural History. The DNA sequences he turned up were compared to those in the US National Institutes of Health's (NIH) GenBank genetic database, and the scientist ultimately identified carrot (Daucus spp.), radish (Raphanus spp.), parsley (Petroselinum spp.), celery (Apium spp.), wild onion (Allium spp.), and cabbage (Brassica spp.) as components.² The testing turned up other botanicals, including yarrow (Achillea spp.) and hibiscus (Hibiscus spp.). The latter is endemic to North Africa and Asia, and has been used in traditional African medicine to lower body temperature and to treat flesh wounds.⁴

“When he came up with the result that had been published, I said, ‘That’s it,’ because immediately I recognized that these are ingredients listed in my texts,” said Dr. Touwaide. “And so I was not surprised.”

At the Smithsonian’s "Science at the Smithsonian" website, an article about the discovery notes that “References to all of the components identified in the medicines can be found in ancient medical texts. Not only does this new discovery validate these ancient texts, but it opens promising avenues for new scientific research and innovative thinking in drug discovery.”¹

“What the Smithsonian [article] fails to note,” said John Scarborough, PhD, professor of pharmacy and history at the University of Wisconsin, “is the pervasive assumption in Classical Antiquity (as well as almost all succeeding eras up to our own time) that foodstuffs also were frequently ‘drugs’ and that culinary lore included almost all ‘common vegetables’ as possessing ‘powers’ or ‘properties’ which ‘acted’ much as did ‘drugs’” (e-mail, November 29, 2010).

Due to the abundance of vegetable-based drug compound recipes in ancient texts, the question of what the tablets may have been meant to treat is a challenging one. (Although, according to Scarborough, the presence of vegetable-based tablets in a tin container is in itself unusual, as Dioscorides—a 1^st century pharmacologist—directed that tin should house animal fats and marrows, not botanicals.) At present, there are 2 primary hypotheses for the use of the tablets, according to Dr. Touwaide. One is that they were meant for application on the skin, and the other is that the tablets were meant to treat intestinal problems. Dr. Touwaide has built a database of all of the plants listed in the Corpus Hippocraticum (a text detailing the 300 or so herbs and natural materials used by the 5^th century BCE Greek physician Hippocrates), as well as in the texts of Dioscorides and the 2^nd century CE Roman physician Galen. Dr. Touwaide plans to expand the database to include other relevant works, and to run increasingly advanced test results through.

The list of plants that has been published only enumerates those for which the researchers have “an exact match at the species level,” according to Dr. Touwaide. Two more categories of botanical ingredients exist, he said: “The second category is a group of plants for which we have alternatives—it can be that or that—and the third [contains plants] that are not yet clarified in our work.”

Dr. Touwaide plans to continue to test and study the tablets. "Now that I have the thing in my hand," he said, "I want to pursue it, because it really is the hottest thing, the sexiest thing, in the history of ancient medicine right now.”

—Ashley Lindstrom

References

1. DNA sequencing reveals simple vegetables in ancient Roman medicines. Smithsonian Institution Science at the Smithsonian website. October 21, 2010. Available at: www.smithsonianscience.org/2010/10/dna-sequencing-reveals-simple-vegetables-in-ancient-roman-medicines/. Accessed November 22, 2010.

2. Lorenzi R. Ancient medical kit held veggie pills. Discovery News. September 14, 2010. Available at: www.news.discovery.com/archaeology/roman-ship-medical-kit.html.  Accessed November 22, 2010.

3. The Institute. Institute for the Preservation of Traditional Medicine website. Available at: http://medicaltraditions.org/institute. Accessed November 30, 2010.

4. Engels G. Herb Profile: Hibiscus. HerbalGram. 2007; No. 74:1-6.