An extract is made by cooking the fruit of an eggplant for about 15 to 30 minutes at about 120 to about 250.degree. C., extracting the juice from the cooked fruit, and adding an oxidant to the juice that reacts with a component in it and changes its color from beige to black. Eggplants such as the Chinese eggplant and oxidants such as ferrous salts, such as ferrous sulfate, work particularly well. The extract can be formulated into various types of products, including pills, tablets, capsules, suppositories, foams, lotions, creams, and enema liquids. The products may be used for treating a variety of medical conditions, including gastrointestinal inflammation, hemorrhoids, skin inflammation, and other problems.