Bromelain
Bromelain is not a single substance, but rather a collection of protein-digesting enzymes (also called proteolytic enzymes) found in pineapple juice and in the stem of pineapple plants. It is primarily produced in Japan, Hawaii, and Taiwan, and much of the original research was performed in the first two of those locations. Subsequently, European researchers developed an interest, and, by 1995, bromelain had become the thirteenth most common individual herbal product sold in Germany.
Bromelain (often in combination with other proteolytic enzymes) is used in Europe to aid in recovery from surgery and athletic injuries, as well as to treat sinusitis and phlebitis.
Bromelain has a long history of use as a digestive enzyme. Unlike most digestive enzymes, bromelain is active both in the acid environment of the stomach and the alkaline environment of the small intestine. This may make it particularly effective as an oral digestive aid.
Bromelain appears to exert a wide variety of therapeutic effects including:
• Antiinflammatory activity
• Appetite reduction
• Burn debridement
• Cancer remission and prevention
• Digestion assistance
• Immune stimulation
• Improved wound healing
• Induced pulmonary edema prevention
• Improved antibiotic absorption
• Inhibition of blood platelet aggregation
• Pain reduction
• Shortening of labor
• Sinusitis relief
• Smooth muscle relaxation
• Reduced swelling
• Ulcer prevention
In terms of Cancer... Bromelain appears to delay metastases considerably, delays onset of skin cancer, and is effectively used in adjunctive tumor therapy. There is also some indication that it has a direct effect on cancer cells. The increased understanding of immunology makes it evident that the solution to cancer is not to be entirely found in chemotherapy or radiation therapy, but in the use of immunotherapy (such as systemic enzyme therapy). Pharmacologic and preclinical studies indicate that bromelain acts as an immunomodulator by inducing the production of distinct cytokines (such as interleukin-1β [IL-1β], IL-6, and IL-8, as well as tumor necrosis factor-γ), and by raising the impaired immunocytotoxicity of monocytes against tumor cells. These findings were recently partially confirmed in mammary tumor patients. Particularly encouraging are animal studies suggesting anti-metastatic properties and inhibition of platelet aggregation associated with metastasis, as well as inhibition of invasiveness and growth of tumor cells. It is interesting to note that the anti-invasive activity might not depend on bromelain’s proteolytic activity. An in vitro study on bromelain and glioma (primary brain tumor) cells found that bromelain significantly and reversibly reduced the adhesion, migration, and invasion of glioma cells. Moreover, normal cell viability was not affected, even after treatment up to 3 months.
In the United States, skin cancer is one of the most common forms of cancer. It is generally agreed that exposure to ultraviolet rays increases an individual’s risk of skin cancer. To determine if bromelain could prevent skin cancer, researchers gave hairless mice 20 mg of bromelain per kilogram of body weight per day for 1 year and then subjected them to ultraviolet light for 15 minutes three times per week for the same period. After 1 year, only 40% of the bromelain group developed skin cancer (as opposed to 100% of the control group). In addition, it took the bromelain group twice as long to develop lesions. An earlier, 6-month study found that mice receiving 80 mg of bromelain per kilogram of body weight did not develop any abrasions after 2 months. Bromelain (and other proteolytic enzymes) appears useful in the direct treatment of cancer. A number of mechanisms seem to be responsible. Bromelain had a significant impact on monocytes, natural killer cells, and lymphocytes in a clinical study of 16 women with breast cancer. Regarding monocytic cytotoxicity, some 40% of the patients responded to bromelain with an increase of cytotoxicity from 7.8% to 54% (bMAK-cell activity).
Dosage
When used as a digestive aid, bromelain should be taken just before a meal (no more than 30 minutes before eating). When used systemically (for inflammation or cancer), bromelain should be taken between meals, on an empty stomach (about 1-1/ 2 hours before or after a meal). The preparation’s potency will dictate dosage. Most bromelain currently marketed in the United States is between 600 and 2400 GDUs. A good dosage with which to begin might be 230 to 250 mg taken three to four times daily.
Safety
High doses (nearly 2 g) of bromelain have been administered with no apparent side effects. No lethal dose 50 (LD50) exists up to 10 g/ kg, so it is deemed to be virtually nontoxic. Long-term use seems to be well-tolerated.
There are few known interactions between bromelain and other medications. However, because bromelain is a potent inhibitor of platelet aggregation (both in vivo and in vitro), caution should be exercised when used with anticoagulants (blood thinners), including Jantoven, Lovenox, and warfarin, as well as over-the-counter nonsteroidal antiinflammatory drugs, including aspirin and ibuprofen. In addition, certain botanicals, including garlic, ginkgo biloba, and ginseng, may increase bleeding risk, so patients should be monitored when these are used in conjunction with bromelain. Clinical studies show that bromelain can increase serum levels of several antibiotics (including tetracycline, amoxicillin, and penicillin) in body fluids and tissues. This can be helpful when attempting to improve an antibiotic’s efficacy; however, it is possible that there could be instances where elevated serum levels of antibiotics would be deleterious.