According to ancient sources, the principal ingredient of absinthe was sometimes used medically to do what?

Question

First used in western medicine in the 17th century what was the drug developed from the bark of the cinchona tree used to treat?

Answer 1

Expel intestinal worms
The ingredient is artemisia absinthium, or wormwood. The de-worming or antihelminthic use is documented in Pliny's "Natural History" (1st century CE).