Proteases (also sometimes referred to as proteolytic enzymes or peptidases) are in use, or have been proposed or tried, for a number of purposes related to medicine or surgery. Some preparations involving protease have undergone successful clinical trials and have regulatory authorization; [1] and some further ones have shown apparently useful effects in experimental medical studies. [2] Proteases have also been used by proponents of alternative therapies, or identified in materials of traditional or folk medicine. [3] A serine protease of human origin, activated protein C, was produced in recombinant form and marketed as Drotrecogin alfa (also known as Xigris (TM)) and licensed for intensive-care treatment of severe sepsis. It was voluntarily withdrawn by the manufacturer in 2011 after being shown to be ineffective. [4] [5]
Some of these uses rely directly on the proteolytic activity: others rely on observations of anti-inflammatory activity.
Tissue plasminogen activator (TPA) is a serine protease occurring in animals including humans. Human-identical TPA (produced industrially by genetically recombinant microorganisms) has an established medical use in the treatment of ischemic stroke: by its proteolytic activity it enables the action of another enzyme (plasmin), which breaks down the protein (fibrin) of blood clots. [6] [7]
Venombin A from snake venom were used in stokes to deplete fibrinogen by forming very weak clots that can be easily dissolved. Available evidence does not support any benefit in such usage. [8]
Debridement involves the removal of dead or damaged tissue from wounds in order to assist healing. Much of the debris to be removed is proteinaceous, and proteolytic enzymes have been applied to this purpose.
Papain is a protease obtained from the latex of the fruit of the papaya tree. It has been used (without regulation) for wound debridement for many years, but in the US in 2008 it was brought under regulation by the U.S. Food and Drug Administration and removed from sale for this purpose, following reports of adverse effects. On the other hand, recent research has been exploring new ways of administering papain for wound debridement. [9]
Papain as well as other proteases, including bromelain, collagenase, trypsin and thermolysin, have also been tried or used according to other reports on the use of proteases for debridement of wounds and burns without damaging healthy tissue. [10]
Maggot therapy for wound debridement is a traditional therapy which was in recent years approved by the FDA. [11] It has been identified that the maggots produce proteolytic enzymes which take part in the debridement process. [12]
Some pathogenic bacteria produce biofilms or exudates containing protein, which in some degree help the bacteria adhere to host tissue, or in some degree physically shield the bacteria or hinder the penetration of substances such as antibiotics administered with the intent that they contact the bacteria. Accordingly, proteolytic enzymes have been tried in conjunction with antibiotics. Thus, it has been reported that Serratia sp. E-15 protease (also known as serratiopeptidase; P07268 ) [13] was effective for eradicating infection caused by biofilm-forming bacteria in an experimental animal model (which involved carrying out experimental limb surgery on rats, at the same time experimentally introducing Staphylococcus infection). The authors considered that "The antibiofilm property of the enzyme may enhance antibiotic efficacy in the treatment of staphylococcal infections." [2]
The same enzyme, when used concomitantly with an antibiotic, was also reported to increase antibiotic concentration at a target site. [14]
Protease is also capable of medical applications. It is one of the enzymes in Sollpura (Liprotamase), a pancreatic enzyme replacement therapy (PERT). It assists in the breakdown of proteins into amino acids and polypeptides. [15]
Bromelain is a protease usually obtained from pineapple stem tissue, which has been medically used for its anti-inflammatory effects (see Bromelain - medical uses).
Serratia E-15 protease (also known as serratiopeptidase [13] or serrapeptidase [16] ) is another protease that has been proposed as an anti-inflammatory agent. [17] Anti-inflammatory effects of this protease have been reported again more recently, [18] and the material has come into some use in alternative or complementary medicine. On the other hand, it does not appear that there are positive clinical trial results for this material of a kind that would be needed to gain regulatory approval for controlled pharmaceutical uses. [19]
Necrosis is a form of cell injury which results in the premature death of cells in living tissue by autolysis. The term "necrosis" came about in the mid-19th century and is commonly attributed to German pathologist Rudolf Virchow, who is often regarded as one of the founders of modern pathology. Necrosis is caused by factors external to the cell or tissue, such as infection, or trauma which result in the unregulated digestion of cell components. In contrast, apoptosis is a naturally occurring programmed and targeted cause of cellular death. While apoptosis often provides beneficial effects to the organism, necrosis is almost always detrimental and can be fatal.
Gangrene is a type of tissue death caused by a lack of blood supply. Symptoms may include a change in skin color to red or black, numbness, swelling, pain, skin breakdown, and coolness. The feet and hands are most commonly affected. If the gangrene is caused by an infectious agent, it may present with a fever or sepsis.
Fibrinolysis is a process that prevents blood clots from growing and becoming problematic. Primary fibrinolysis is a normal body process, while secondary fibrinolysis is the breakdown of clots due to a medicine, a medical disorder, or some other cause.
Necrotizing fasciitis (NF), also known as flesh-eating disease, is a bacterial infection that results in the death of parts of the body's soft tissue. It is a severe disease of sudden onset that spreads rapidly. Symptoms usually include red or purple skin in the affected area, severe pain, fever, and vomiting. The most commonly affected areas are the limbs and perineum.
A wound is any disruption of or damage to living tissue, such as skin, mucous membranes, or organs. Wounds can either be the sudden result of direct trauma, or can develop slowly over time due to underlying disease processes such as diabetes mellitus, venous/arterial insufficiency, or immunologic disease. Wounds can vary greatly in their appearance depending on wound location, injury mechanism, depth of injury, timing of onset, and wound sterility, among other factors. Treatment strategies for wounds will vary based on the classification of the wound, therefore it is essential that wounds be thoroughly evaluated by a healthcare professional for proper management. In normal physiology, all wounds will undergo a series of steps collectively known as the wound healing process, which include hemostasis, inflammation, proliferation, and tissue remodeling. Age, tissue oxygenation, stress, underlying medical conditions, and certain medications are just a few of the many factors known to affect the rate of wound healing.
A maggot is the larva of a fly ; it is applied in particular to the larvae of Brachycera flies, such as houseflies, cheese flies, and blowflies, rather than larvae of the Nematocera, such as mosquitoes and crane flies.
Bromelain is an enzyme extract derived from the stems of pineapples, although it exists in all parts of the fresh plant and fruit. The extract has a history of folk medicine use. As a culinary ingredient, it may be used as a meat tenderizer.
Debridement is the medical removal of dead, damaged, or infected tissue to improve the healing potential of the remaining healthy tissue. Removal may be surgical, mechanical, chemical, autolytic (self-digestion), or by maggot therapy.
Urokinase, also known as urokinase-type plasminogen activator (uPA), is a serine protease present in humans and other animals. The human urokinase protein was discovered, but not named, by McFarlane and Pilling in 1947. Urokinase was originally isolated from human urine, and it is also present in the blood and in the extracellular matrix of many tissues. The primary physiological substrate of this enzyme is plasminogen, which is an inactive form (zymogen) of the serine protease plasmin. Activation of plasmin triggers a proteolytic cascade that, depending on the physiological environment, participates in thrombolysis or extracellular matrix degradation. This cascade had been involved in vascular diseases and cancer progression.
Papain, also known as papaya proteinase I, is a cysteine protease enzyme present in papaya and mountain papaya. It is the namesake member of the papain-like protease family.
Maggot therapy is a type of biotherapy involving the introduction of live, disinfected maggots into non-healing skin and soft-tissue wounds of a human or other animal for the purpose of cleaning out the necrotic (dead) tissue within a wound (debridement), and disinfection.
A chronic wound is a wound that does not heal in an orderly set of stages and in a predictable amount of time the way most wounds do; wounds that do not heal within three months are often considered chronic. Chronic wounds seem to be detained in one or more of the phases of wound healing. For example, chronic wounds often remain in the inflammatory stage for too long. To overcome that stage and jump-start the healing process, a number of factors need to be addressed such as bacterial burden, necrotic tissue, and moisture balance of the whole wound. In acute wounds, there is a precise balance between production and degradation of molecules such as collagen; in chronic wounds this balance is lost and degradation plays too large a role.
Collagenases are enzymes that break the peptide bonds in collagen. They assist in destroying extracellular structures in the pathogenesis of bacteria such as Clostridium. They are considered a virulence factor, facilitating the spread of gas gangrene. They normally target the connective tissue in muscle cells and other body organs.
Actinidain is a type of cysteine protease enzyme found in fruits including kiwifruit, pineapple, mango, banana, figs, and papaya. This enzyme is part of the peptidase C1 family of papain-like proteases.
Serratiopeptidase is a proteolytic enzyme (protease) produced by enterobacterium Serratia sp. E-15, now known as Serratia marcescens ATCC 21074. This microorganism was originally isolated in the late 1960s from silkworm intestine. Serratiopeptidase is present in the silkworm intestine and allows the emerging moth to dissolve its cocoon. Serratiopeptase is produced by purification from culture of Serratia E-15 bacteria. It is a member of the Peptidase M10B (Matrixin) family.
Wound bed preparation (WBP) is a systematic approach to wound management by identifying and removing barriers to healing. The concept was originally developed in plastic surgery. It includes wound assessment, debridement, moisture balance, bacterial balance, and wound cleaning.
Zingibain, zingipain, or ginger protease is a cysteine protease enzyme found in ginger rhizomes. It catalyses the preferential cleavage of peptides with a proline residue at the P2 position. It has two distinct forms, ginger protease I (GP-I) and ginger protease II (GP-II).
Plasminogen activator Pla is an enzyme. This enzyme catalyses the following chemical reaction
Bromelain, a concentrate of proteolytic enzymes from the pineapple plant, is used in medicine. It is approved in the European Union for the debridement of severe burn wounds under the brand name Nexobrid. It was developed by MediWound.
Insects have long been used in medicine, both traditional and modern, sometimes with little evidence of their effectiveness.