Papain comes from the latex of green papaya fruit.
Bromelain comes from pineapple stems and fruits. They are called proteolytic enzymes because they break up biological products like thick mucus. Proteolytic enzymes are involved with repair and healing in the body. They have anti-inflammatory action. In the 50's, dozens of clinical trials that showed that these enzymes yielded clear positive results, when they were administered via buccal route, i.e. dissolved slowly between the cheek and gums.