Scientists had discovered pills in a 2,000-year-old shipwreck around 21 years ago.
Now they are trying to unravel the mystery of whether the pills were, in fact, created and used as effective plant-based medicines.
Around 130 B.C., a ship, identified as the Relitto del Pozzino, sank off Tuscany, Italy. Among the artifacts found on board in 1989 were glass cups, a pitcher and ceramics.
Its cargo also included a chest that contained various items related to the medical profession: a copper bleeding cup and 136 boxwood vials and tin containers, reports AOL News.
Inside one of the tin vessels, archaeologists found several circular tablets, many still completely dry.
Using DNA sequencing, Robert Fleischer, an evolutionary geneticist with the Smithsonian's Center for Conservation and Evolutionary Genetics in Washington, D.C, has identified some of the plant components in the tablets - carrot, radish, parsley, celery, wild onion, cabbage, alfalfa, oak and hibiscus.
This is similar to the recent archaeological discovery in China of a 2,400-year-old pot of soup in which the broth was found inside a sealed cauldron.
But the discovery of these tablets in the shipwreck marks the first time ever that archaeological remains of ancient medicines have been found and the first time DNA analysis has been used in the research.
So far, the various things observed in the pills are also found in ancient medical texts, according to Alain Touwaide, scientific director of the Institute for the Preservation of Medical Traditions in Washington.
Applying DNA analysis to the tablets, Fleischer noticed that they differed in their makeup.
"What was a surprise to me was that there were so many things in each pill, and they weren't identical-the pills had different things in them," he said.
As Fleischer and Touwaide continue researching the tablets, they hope to determine their original purpose.
"When I look in my texts-what these plants were used for -- the only common denominator I find is that they were used for gastrointestinal trouble," said Touwaide.
"I came up with the idea that these tablets might have been used to treat dysentery for the people on the boat, and this was quite a problem among sailors," he added.
Both Fleischer and Touwaide hope their research signals a new paradigm in pharmacological studies as the ageless tablets seem to reach across thousands of years of history and medicine.