Some people use a product (Phlogenzym) for arthritis (osteoarthritis) that combines bromelain with trypsin (a protein) and rutin (a substance found in buckwheat). Bromelain used in this way seems to reduce pain and improve knee function in people with arthritis.ore evidence is needed to rate the effectiveness of bromelain for these uses. 1  Arthritis (osteoarthritis). 2  Arthritis (rheumatoid arthritis). 3  Knee pain. 4  Severe burns. 5  Inflammation. 6  Sinusitis. 7  Improving antibiotic absorption. 8  Hay fever. 9  Preventing cancer. 10  Shortening of labor. 11  Ulcerative colitis. 12  Other conditions.