Introduction

Supportive dietary supplementation may be helpful with problems such as inflammation, and digestive disorders. Quoting from the excellent book on Dog Cancer "The Natural Vets Guide to Preventing and Treating Cancer in Dogs" by Shawn Messonier DVM (available for purchase from our website) ... "Additionally various stresses sch as illness, allergy, food intolerance, age {older pets may have reduced digestive enzyme capability}, and radiation, in addition to various orally administered medications {anti biotics and chemotherapy} can decrease gastrointestinal function. This results in poor digestion and incomplete absorption of utrients. Supplying digestive enzymes at these times can improve digestion and absorption.

In the book, Prescription for Herbal Healing, curcumin is noted as causing the death of cancer cells arising from several different types of tissue. By curtailing the activity of platelet-activating factor (PAF), which is necessary for the formation of new blood vessels that tumors need to grow, curcumin can keep tumors from spreading. Curcumin can also aid recovery from cancer by stimulating the immune system. In Dr. Kidd's Guide to Herbal Dog Care, he believes tumeric to have anticancer properties, anti-inflammatory properties, antimicrobial characteristics, cardiovascular system benefits (inhibits platelet aggregation and interferes with intestinal cholesterol uptake), and intestinal benefits (decreases gas formation). He believes it is the perfect herb to sprinkle on your dog's food, as dogs relish its taste.

Turmeric Root (Curcuma longa). Adding curcumin, the active substance found in turmeric, to human cells with the blood cancer multiple myeloma, Dr. Bharat B. Aggarwal of the University of Texas MD Anderson Cancer Center in Houston and his colleagues, not only stopped cancer cells from replicating but also killed the cells that were left.

Mayo Clinic medical oncologist Timothy Moynihan, M.D. states that "Curcumin is thought to have antioxidant properties, which means it may decrease swelling and inflammation. It's being explored as a cancer treatment because inflammation appears to play a role in cancer. Lab research suggests that curcumin may slow the spread of cancer and the growth of new tumor blood vessels. It may also cause cancer cells to die. In the lab, curcumin has been studied for use in treating or preventing colon, skin and breast cancers."

Bioflavonoids

Inflammation, oxidative stress and immune dysfunction underlie many health disorders and disease states. It is fundamental to address these processes in order to maximise health potential. Studies have supported the use of Quercetin, Bromelain and Rutin to down regulate inflammation, reduce oxidative stress, modulate viral activity and to support immune health and wound healing processes.

Quercetin

1. Anti-inflammatory

   Quercetin has the potential to support inflammatory related disorders such as asthma, cancer, arthritis, inflammatory bowel disorders, inflammatory oedema and cardiovascular disease.

   Many substances have been researched for their anti-inflammatory effect; one of the most potent of the natural substances is Quercetin. Quercetin down regulates a number of inflammatory mediators including:

   1. Cyclo-oxygenase 1 and Lipoxygenase 2 pathways
   2. NF-kappa B 3, Tumour Necrosis Factor alpha 4, Prostaglandin E2 5, Series 4 Leukotrienes 6 and Histamine.7
   
   
2. Cancer Support

Recent research has linked inflammation to the progression of cancer development. Clinical studies on non steroidal anti-inflammatory drugs (NSAIDs) have suggested a potential benefit for anti-inflammatory medication in cancer support programs. However one of the concerns with NSAIDs and aspirin is their ability to inhibit only one aspect of the inflammatory process (cyclooxygenase). Quercetin has been shown to modulate both the cyclooxygenase (COX) and lipoxygenase (LO) pathways therefore down regulating a variety of inflammatory mediators 8, including the metabolite 5-HETE which has been strongly associated with cancer growth and development. 9

Figure 1: Represents the effect quercetin has on inflammatory pathways compared with NSAIDs and aspirin.

Quercetin has also been shown to up regulate apoptosis (healthy programmed cell death) and down regulate mitosis (cell division) thus having a direct effect on cancer cell growth and development. Due to its ability to up regulate apoptosis, quercetin has also shown promising benefit as support therapy during chemotherapy. 10, 11

3. Antioxidant

One of the reasons flavonoids are reported to exert multiple biological effects is due to their free radical scavenging and antioxidant properties. 12 Quercetin has been shown to inhibit LDL oxidation in vitro 13 and protect against oxidative damage in a number of health conditions. For example quercetin has been shown to protect neurovasculature structures in skin from oxidative damage. 14

4. Antiviral and Immune Support

In vitro studies show quercetin possesses antiviral properties. A study conducted on herpes simplex type 1, polio-virus type 1, parainfluenza virus type 3 (Pf-3), and respiratory syncytial virus (RSV) found that quercetin caused a concentration-dependent reduction in the infectivity of each virus. In addition, it reduced intracellular replication of each virus. 15

5. Allergies

As mentioned in the inflammatory section, quercetin has the ability to down regulate histamine and stabilize mast cells. In animal studies quercetin has also been shown to inhibit anaphylactic contraction of smooth muscle. 16

6. Eye Health

Aldose reductase, the enzyme which catalyzes the conversion of glucose to sorbitol, is especially important in the eye, and plays a part in the formation of diabetic cataracts. Quercetin is a strong inhibitor of human lens aldose reductase. 17

Rutin

1. Anti-inflammatory, Antioxidant, Immune Support & Heavy Metal Conjugation

Like quercetin, rutin has shown to help support inflammatory processes. It has been suggested that rutin may play a more specific role in chronic inflammatory processes. 18 Rutin also possesses antioxidant properties and may help to support immune health. In animal studies rutin has been shown to increase the total of superoxide dismutase (an antioxidant enzyme) activity in the liver. 19 It has also been suggested that flavonoids such as rutin and quercetin possess iron chelating properties. 20

2. Reduce Capillary Permeability

Studies dating back to the 1960's have been conducted on flavonoids' potential to act as capillary stabilizers. A recent animal study in 2003 found that a flavonoid compound could completely abolish arachidonate induced vascular permeability. 21 A Cochrane review in 2000 found that rutosides (a flavonoid compound) appeared to relieve symptoms of venous insufficiency in late pregnancy, although safety was not confirmed during pregnancy. 22

3. Connective Tissue Support

There is evidence to suggest that flavonoids may be beneficial to connective tissue for several reasons, which include the limiting of inflammation and associated tissue degradation, the improvement of local circulation, as well as the promoting of a strong collagen matrix. 23

Bromelain

1. Reduces Inflammation

Bromelain can help to reduce oedema and inflammation. In vivo and in vitro studies have suggested that bromelain has the ability to reduce inflammatory mediators such as prostaglandin E2 and substance P. 24 Bromelain has also been shown to reduce bradykinin which is also involved in pain and inflammation. 25

2. Supports Wound Healing

Bromelain may play an important role in wound healing; it has been shown to improve healing time following trauma and surgical procedures. 26 It has been suggested that a non-proteolytic component of bromelain is involved in the wound healing properties of the substance.

3. Cancer

Results from preclinical and pharmacological studies recommend bromelain as a complementary tumour therapy. Bromelain acts as:

1. Immunomodulator: Bromelain raises the activity of impaired monocytes against tumour cells. 27
2. Inducer of cytokines: Bromelain induces the production of distant cytokines such as tumour necrosis factor-a, interleukin (11)-beta, Il-6, and Il8. 27
3. Anti-inflammatory: Bromelain reduces inflammatory mediators.


4. Improves Nutrient Absorption

It has been suggested that bromelain has the potential to improve the absorption of flavonoids such as rutin and quercetin however further research is required. 28 Bromelain is also well known for its proteolytic properties and may be used to help improve the digestion of proteins. In humans, bromelain has also been shown to increase excretion of antibiotics. 29

References

1. O'Leary KA, et al, Effect of flavonoids and vitamin E on cyclooxygenase-2 (COX-2) transcription. Mutat Res. 2004 Jul 13;551(1-2):245-54
2. Borbulevych OY et al, Lipoxygenase interactions with natural flavonoid, quercetin, reveal a complex with protocatechuic acid in its X-ray structure at 2.1 A resolution. Proteins. 2004 Jan 1;54(1):13-9.
3. Ishikawa Y, Sugiyama H, Stylianou E, Kitamura M. Bioflavonoid quercetin inhibits interleukin-1-induced transcriptional expression of monocyte chemoattractant protein-1 in glomerular cells via suppression of nuclear factor-kappaB. J Am Soc Nephrol. 1999 Nov;10(11):2290-6
4. Wadsworth TL et al, Effects of Ginkgo biloba extract (Egb 761) and quercetin on lipopolysaccharide-induced signalling pathways involved in the release of tumor necrosis factor-alpha. Biochem Pharmacol. 2001 Oct1;62(7):963-74
5. Mascolo N et al, Flavonoids, leucocyte migration, and eicosanoids. J Pharm Pharmacol. 40:293-295,1988
6. Wang ZY et al, Effect of leukotriene B4 on arachidonate metabolism and activation of blood cells and endothelial cells. Zhongguo Yao Li Xue Bao. 1993 Mar;14(2):155-8
7. Miller A. The etiologies, pathophysiology, and alternative/complementary treatment of asthma. Alternative Medicine Review. 6(1):20-47, 2001
8. Wallace JM. Nutritional and botanical modulation of the inflammatory cascade--eicosanoids, cyclooxygenases, and lipoxygenases--as an adjunct in cancer therapy. Integr Cancer Ther. 2002 Mar;1(1):7-37; discussion 37.
9. Bio Concepts Publishing " Cancer: A Nutritional/Biochemical Approach" 2nd edition Henry Osiecki Pg 76
10. Debes A et al. Sensitization of human Ewing's tumor cells to chemotherapy and heat treatment by the bioflavonoid quercetin. Anticancer Res. 2003 Jul-Aug;23(4):3359-66.
11. Russo M et al. Flavonoid quercetin sensitizes a CD95-resistant cell line to apoptosis by activating protein kinase C-alpha. Oncogene. 2003 May 22;22(21):3330-42.
12. Chen YT, Zheng RL, Jia ZJ, Ju Y. Flavonoids as superoxide scavengers and antioxidants. Free Radic Biol Med 1990;9:19-21.
13. Martinez-Florez S et al. Flavonoids: properties and anti-oxidizing action. Nutr Hosp. 2002 Nov-Dec;17(6):271-8.
14. Skaper SD, Fabris M, Ferrari V, et al. Quercetin protects cutaneous tissue-associated cell types including sensory neurons from oxidative stress induced by glutathyone depletion: cooperative effects of ascorbic acid. Free Radic Biol Med 1997;22:669-678.
15. Kaul TN et al. Antiviral effect of flavonoids on human viruses. J Med Virol. 1985 Jan;15(1):71-9.
16. Fanning MJ et al. Quercetin inhibits anaphylactic contraction of guinea pig ileum smooth muscle. Int Arch Allergy Appl Immunol. 1983;71(4):371-3
17. Chaudry PS, Cabera J, Juliani HR, Varma SD. Inhibition of human lens aldose reductase by flavonoids, sulindac, and indomethacin. Biochem Pharmacol 1983;32:1995- 1998.
18. Rotelli AE et al, Comparative study of flavonoids in experimental models of inflammation. Pharmacol Res. 2003 Dec;48(6):601-6.
19. Gao Z et al, Antioxidant status and mineral contents in tissues of rutin and baicalin fed rats. Life Sci. 2003 Aug 8;73(12):1599-607.
20. Juurlink BH, Paterson PG. Review of oxidative stress in brain and spinal cord injury: suggestions for pharmacological and nutritional management strategies. J Spinal Cord Med. 1998 Oct;21(4):309-34.
21. Alvarez-Guerra M et al, Vascular permeabilization by intravenous arachidonate in the rat peritoneal cavity: antagonism by antioxidants. Eur J Pharmacol. 2003 Apr 11;466(1-2):199-205
22. Young GL, Jewell D. Interventions for varicosities and leg oedema in pregnancy. Cochrane Database Syst Rev. 2000(2):CD001066.
23. Teixeira S. Bioflavonoids: proanthocyanidins and quercetin and their potential roles in treating musculoskeletal conditions. J Orthop Sports Phys Ther. 2002 Jul;32(7):357- 63.
24. Inoue K et al. Effect of etodolac on prostaglandin E2 biosynthesis, active oxygen generation and bradykinin formation. Prostaglandins Leukot Essent Fatty Acids. 1994 Dec;51(6):457-62.
25. Kumakura S, Yamashita M, Tsurufuji S. Effect of bromelain on kaolin-induced inflammation in rats. Eur J Pharmacol. 1988 Jun 10;150(3):295-301.
26. MacKay et al. Nutritional Support for Wound Healing. Alternative Medical Review. 2003 Nov;8(4):359-77
27. Maurer HR. Bromelain: biochemistry, pharmacology and medical use. Cell Mol Life Sci. 2001 Aug;58(9):1234-45.
28. Shoskes DA et al, Quercetin in men with category III chronic prostatotos: a preliminary prospective, double-blind, placebo-controlled trial. Urology 1999 Dec;54(6):960-3.
29. Maurer HR. Bromelain: Ibid. :1234-45

Enzymes

Enzymes have aptly been called the "Fountains of Life". They are biological catalysts that are ubiquitously found in nature and are responsible for the myriad reactions taking place in our bodies. Not only do they orchestrate the break down of complex molecules into simple molecules useful to our body, but they also regulate and control each and every process that keeps the body functioning harmoniously.

Consequently, their therapeutic applications are equally varied and as far-reaching, from digestive aids and nutritional supplements to treatment of pancreatic insufficiency in diseases such as chronic pancreatitis and even for the lysis of blood clots especially for treating cardio vascular diseases (streptokinase, tissue plasminogen activator, urokinase).

The following article takes a look at some of the varied applications of enzymes as therapeutic molecules.

Enzyme therapy is not new to us. Several evidences show that it has been in practice since times ancient. Enzyme therapy began with using enzymes from herbal origin for curing certain ailments. The enzyme papain is obtained from the leaves and fruit of the papaya plant Carica papaya while the enzyme bromelain is obtained from the pineapple plant stem Ananas comosus. These fruits or parts of plants have been used therapeutically by the ancient people of Central and South America. Pineapples have been used as a folk medicine by the natives of the tropics for centuries. The fruit has been put to multiple uses: as a digestive aid, as a cleansing agent to improve the texture of the skin and even to promote the healing of wounds (1). The enzyme ficin obtained from the fig plant has been employed for treating cancer since times ancient. This has been documented in the Bible (Second book of Kings, Chapter 20, Verse 7). In Europe, during the Middle Ages, early forms of enzyme therapy were practiced, in which topical enzyme preparations were used to heal ulcers and warts.

Beginning in the 1900s, proteolytic enzyme extracts of pancreas (pancreatin) were used systemically with some success for treating certain cancers. In the early 1950s it was discovered that intravenous trypsin was capable of relieving the symptoms of many different inflammatory conditions, including rheumatoid arthritis, ulcerative colitis, and atypical viral pneumonia. Subsequently intramuscular enzyme injections were found to be beneficial in counteracting post-surgical swelling (edema), treating thrombophlebitis and lower back strain, and rapidly healing bruises caused by sports injuries.

Later on pancreatic enzymes were added to mixtures of enzymes from plant origin. Initially enzyme therapy was followed empirically but over the years systematic scientific work has lead to elucidation of mode of action so as to support applications.

Since non-invasive routes of administration of drugs are preferred over invasive routes, soon, the possibility of developing oral formulations of proteolytic enzymes was explored. It is essential that any enzyme preparation be properly enterically coated so as to release the enzymes in the intestines, where they can be absorbed and not in the stomach where they can be degraded. Around 35 years ago it was shown that enterically coated enzymes are equally useful. Oral proteolytic enzymes have been used successfully ever since for treating inflammatory conditions. The intestinal absorption of orally administered serrapeptase has been demonstrated. to achieve an ideal therapeutic effect.

Thus, Modern Day systemic enzyme therapy involves orally administering high doses of mixtures of enzymes from plant, animal and microbial origin. Some of them include other constituents such as anti-oxidants as well.

Pioneering work in the field of Enzyme Therapy has been done in Germany independently, by Dr Hans Nieper, as well as Dr. Max Wolf along with the American Doctor, Dr Benitez. They successfully showed that mixtures of enzymes had positive effects in people with vascular diseases, lymphedema, certain viral infections, and in the healing of injuries and inflammations. They reached the conclusion that, in fact it is the deficiency of proteolytic enzymes that was a primary factor in premature aging. As we age, the level of proteolytic enzymes in our body is lowered. This leads to disturbance in the physiology and metabolism of the individual often leading to diseased conditions. Also this disturbed equilibrium deteriorates the immune status.

Effects of enzymes shown by Dr. Wolf and Dr. Benitez include :

1. Reduced swelling and inflammation
2. Enhanced immune function
3. Improved circulation
4. Reduction in pain
5. Strengthen connective tissue
6. More rapid recovery from traumatic injury
7. Minimal scar formation
8. Prevention of serious consequences of injury
9. Management of rheumatic diseases, such as rheumatoid arthritis, soft tissue rheumatism and ankylosing spondylitis

• Enzymes as digestive aids and dietary supplements:

The natural production of enzymes slows down as the body ages. Hence, selected enzymes are given as supplements to boost up the enzyme levels thereby normalizing enzyme levels and consequently metabolism and repair.

• Enzymes as fibrinolytic agents:

Conventionally, streptokinase and tissue plasminogen activator or urokinase are being used as fibrinolytic agents following heart attack. The ability of other proteolytic enzymes such as serratiopeptidase to bring about fibrinolysis and digest arterial plaque makes them attractive molecules for cardiovascular disease.

• Enzymes as mucolytic agents:

Proteolytic enzymes like bromelain and serratiopeptidase have shown mucolytic activity and thus have found use in treating respiratory tract diseases such as sinusitis and bronchitis. (22)

• Enzymes as NSAIDS (non steroidal anti inflammatory drugs):

The anti-inflammatory activity of proteolytic enzymes has been attributed to several mechanisms. They can reduce the swelling on mucous membranes, decrease capillary permeability, dissolve blood clot-forming fibrin deposits and microthrombi. Enzymes reduce the viscosity of the blood and thus improve circulation. This consequently increases the supply of oxygen and nutrients to traumatized tissue, at the same time transporting harmful waste products away from it. Bromelain has been shown to inhibit platelet aggregation by using in vitro and in vivo models (21).

Proteolytic enzymes also help break down plasma proteins and cellular debris at the site of an injury into smaller fragments facilitating their passage through the lymphatic system and resulting in more rapid resolution of swelling. The net result is relief of pain and discomfort. Comparative studies in animal models for anti-inflammatory action of proteolytic enzymes with standard drugs such as phenylbutazone, hydrocortisone, indomethacin, and acetylsalicylic acid (aspirin) revealed that the enzymes were on par with the standard drugs and at times even superior (3).

• Enzymes as healing agents:

Due to the above properties, enzymes act as excellent healing agents for minor musculoskeletal injuries, and accelerate recovery in surgeries and burns (14,15,16). Proteolytic enzymes have been of particular use to sportsmen for reducing bruising, swelling, pain and discomfort and improving healing thereby putting athletes back in action. Studies were conducted in Germany on hockey players and skiers to prove this and the enzyme formulations proved to be far more effective than non-steroidal anti-inflammatory drugs (NSAIDS) like ibuprofen and aspirin (1, 2).

• Enzymes and heart disease

Due to their anti-inflammatory activity, proteolytic enzymes like bromelain have been found useful for cardiovascular disease such as atherosclerosis and coronary heart disease (17,19). The enzyme serratiopeptidase is anti-inflammatory as well as fibrinolytic making it very suitable as a drug for keeping away heart disease. It is a blood thinning agent without the side effects of conventional drug thinning agents like Aspirin.

• Enzymes as analgesic agents:

It is also thought that the analgesic effect of proteolytic enzymes is due to their cleavage of bradykinin, a messenger molecule involved in pain signaling. However, according to another theory, peptidases such as trypsin may be acting not as anti-inflammatory agents but rather as accelerants of the inflammatory process, thereby shortening its duration.

• Enzymes as novel antimicrobial agents:

Overuse and misuse of antibiotics is leading us towards a world in which there would be no effective treatment available for the very infections that were once upon a time curable. Besides, the steadily emerging antibiotic resistance, antibiotics have other limitations such as numerous side effects and toxicities. Therefore, there is a constant need for looking for new antimicrobials to combat these limitations.

Proteolytic enzymes are indeed quite amazing. They have been found to be useful against certain bacterial infections. Papain and trypsin inhibit the growth of pathogens whereas bromelain, trypsin and chymotrypsin are known to increase the bioavailability of antibiotics: when combined with antibiotics enzymes can increase the concentration of the drug at the site of infection leading to rapid control of infection. Synergistic action of enzyme - antibiotic mixtures could be an answer to the several problems associated with antibiotic therapy. This was proved using proteolytic enzymes in conjunction with Ampicillin, Tetracyclines and Trimethoprim. Enzyme - antibiotic combinations have proved to be of particular use for treatment of urinary tract infections.

Proteolytic enzymes also have activity against the otherwise difficult to treat fungi. Antiviral activity of different enzymes has been recorded. At last, do we have an answer to the escalating drug resistance problems associated with bacteria, fungi and viruses?

• Enzymes as immunomodulators:

Enzymes are an indispensable part of the regulatory mechanisms involved in the Immune System of our body. It has been found that enzymes can act as wonderful immunomodulators. They play a significant role in inflammation and other processes of the Immune System.

They are known to induce or enhance the production of cytokines such as tumour necrosis factor, interferon (IFN-g), interleukins such as IL-1, Il-6 (18).

They are known to bring about a 7-10 fold increase in the phagocytic activity of macrophages and in the potency of NK cells. Enzymes bring about proteolytic modification of cell-surface adhesion molecules, which play an important role in auto-immune diseases such as arthritis and guide inflammatory cells to their targets.

Circulating immune complexes are the primary causes of auto-immune diseases such as rheumatoid arthritis, glomerulonephritis, type 1 diabetes, multiple sclerosis etc. Proteolytic enzymes such as trypsin, chymotrypsin and papain are capable of preventing the formation of such complexes, facilitate the breaking up these complexes enhancing their lymphatic drainage.

A study of the immunological basis of protease therapy (trypsin, papain, chymotrypsin, bromelain) for type I diabetes revealed that the proteins present on T cells and antigen presenting cells changed along with changed cytokine profiles. The authors concluded that proteases have pleiotropic immunological effects and thus they potentially have an immunomodulatory role in chronic inflammatory diseases and Th-1 mediated oedema formation (12).

• Enzymes as novel anticancer agents:

Studies have shown that enzyme therapy can reduce the adverse effects caused by radiotherapy and chemotherapy. The survival of patients with certain types of tumours may be prolonged with systemic enzyme therapy along with quality of life. Although, the exact role of enzymes is not clear, the beneficial role of enzymes has been attributed to the anti-inflammatory property of enzymes. (13). Other possibilities include digestion of adhesion molecules present on tumour cells and a possible role in differentiation of tumour cells (20). In general, proteolytic enzymes have been suggested as complementary therapy with the usual chemotherapeutic practices.

• Safety issues and enzymes:

The long term safety of enzyme supplements has been explored in great details. The result is that enzymes are generally found to be highly safe and no toxic limit no matter how much you take or how long you take them. It is the lack of enzymes that causes problems, not taking too many. Enzyme action is highly specific and is well known and well characterized. Each enzyme has its own specific role and activity and has typical biochemical properties. Therefore there are few side effects. Healthy tissues and cells have natura mechanisms protecting them from enzyme action. The body is full of checks and balances including lots of enzyme inhibitors, which allow the enzymes to function properly without self-digestion. Enzymes are used for wound healing because they selectively degrade dead tissue and infected tissue wgile leaving the healing tissue growing. Enzymes are used to remove tumours: they attack the cancerous tissue and remove it while facilitating growth of healthy tissue. This built-in natural selective property of enzymes can be seen on surface wounds and tumours (Enzyme Therapy, Max Wolf). No known toxicity at any level of enzyme dosing in animal / human studies has been recorded. Animals survived large quantities of enzymes without damage so it has been impossible to find LD 50. Rats fed with human doses have shown no ill effects.

References

1. Engel A Erfahrungsbericht Ÿber das PrSparat Wobenzym bei den Olympischen Spielen 1984 in Los Angeles. Report from the Allgemein Kranken-haus, Vienna, University Orthopedic Clinic. 1985.
2. Muller-Hepburn W. Anwendung von Enzymen in der Sportmedizin. Forum prakt Allg.-Arzt. 1979; 18:7-10.
3. Netti C, Bandi C, Pecile A. Anti-inflammatory action of proteolytic enzymes of animal, vegetable or bacterial origin administered orally com-pared with that of known antiphlogistic compounds. Il Farmaco. 1972;27:453-466.
4. Logan D, King L. Proteolytic enzymes in urethral edema: A laboratory study. Invest Urol. 1965;3:17-20.
5. Moss J, Frazier C, Martin G. Bromelains. The pharmacology of the enzymes. Arch Int Pharmacodyn. 1963;145:166-189.
6. Monkhouse F. An investigation of the coagulation defect brought about in rabbits and dogs by the intravenous injection of papain. Can J Biochem Physiol. 1954;33:112.121.
7. Kapur B. Talwar J, Gulati S. Use of papase in prevention of experimental peritoneal adhesions. Surgery, 1969;65:629-632.
8. Ochsner A, Storck A. The prevention of peritoneal adhesions by papain. Ann Surg. 1936;104:736-747.
9. Zatuchni G, Colombi D. Bromelain therapy for the prevention of episiotomy pain. Obst Gynecol. 1967;29:275-278.
10. Metro P, Horton R. Plant enzymes in oral surgery. Oral Surg. 1965;19:309-316.
11. Leipner J, Iten F, Saller R. BioDrugs. 2001;15(12):779-89.Therapy with proteolytic enzymes in rheumatic disorders.
12. Roep BO, van den Engel NK, van Halteren AG, Duinkerken G, Martin S. Diabetologia. 2002 May;45(5):686-92. Epub 2002 Mar 28. Modulation of autoimmunity to beta-cell antigens by proteases.
13. Systemic enzyme therapy in oncology: effect and mode of action. Leipner J, Saller R. Drugs. 2000 Apr;59(4):769-80. PMID: 10804034
14. Masson M. Bromelain in the treatment of blunt injuries to the musculoskeletal system. A case observation study by an orthopedic surgeon in private practice. Fortschr Med 1995;113:303-6.
15. Levensen S. Supportive therapy in burn care. Debriding agents. J Trauma 1979;19(11 Suppl):8-30.
16. Seltzer AP. Minimizing post-operative edema and ecchymoses by the use of an oral enzyme preparation (bromelain). EENT Monthly 1962;41:813-7.
17. Gutfreund AE, Taussig SJ, Morris AK. Effect of oral bromelain on blood pressure and heart rate of hypertensive patients. Hawaii Med J 1978;37:143-6.
18. Desser L, Rehberger A, Paukovits W. Proteolytic enzymes and amylase induce cytokine production in peripheral blood mononuclear cells in vitro. Cancer Biother 1994;9:253-63.
19. Nieper HA. Effect of bromelain on coronary heart disease and angina pectoris. Acta Med Empirica 1978;5:274-8.
20. Batkin S, Taussig SJ, Szekerezes J. Antimetastatic effect of bromelain with or without its proteolytic and anticoagulant activity. J Cancer Res Clin Oncol. 1988; 114:507-508.
21. Metzig C, Grabowska E, Eckert K, et al. Bromelain proteases reduce human platelet aggregation in vitro, adhesion to bovine endothelial cells and thrombus formation in rat vessels in vivo. In Vivo. 1999; 13:7-12.
22. A New Method for Evaluating Mucolytic Expectorant Activity and its Application
II. Application to two proteolytic enzymes, serrapeptase and seaprose* By Y. Kase, H. Seo, Y. Oyama, M. Sakata, K. Tomoda, K. Takahama, T. Hitoshi, Y. Okano, and T. Miyata Arzneim.-Forsch. / Drug Res. 32 (1), Nr. 4 (1982)
23. Chandler DS, Mynott TL. Bromelain protects piglets from diarrhea caused by oral challenge with K88 positive enterotoxigenic Escherichia coli. Gut. 1998; 43:196-202.
24. Mynott TL, Guandalini S, Raimondi F, Fasano A. Bromelain prevents secretion caused by Vibrio cholerae and Escherichia coli enterotoxins in rabbit ileum in vitro. Gastroenterology. 1997; 113:175-184.
25. Mori S, Ojima Y, Hirose T, et al. The clinical effect of proteolytic enzyme containing bromelain and trypsin on urinary tract infection evaluated by double blind method. Acta Obstet GynaecolJpn 1972;19:147-53.
26. Taussig SJ, Batkin S. Bromelain, the enzyme complex of pineapple (Ananas comosus) and its clinical application. J Ethnopharmcol. 1988; 22:191-203.