S2 L6 Pharmaceutical uses of enzymes

1. S2 L6 Pharmaceutical uses of enzymes Anna Drew

2. Enzymes • catalyse (speed up) chemical reactions • involved in most processes in a biological cell • proteins • specific • activity affected by • other molecules (inhibitors) • temperature • chemical environment (pH) • concentration of substrate • wide range of uses • household products • pharmaceutical

3. Papain • Cystine protease hydrolase enzyme • Source: • Papaya (Carica papaya) • Mountain papaya (Vasconcellea cundinamarcensis) • latex from the neck of fruit is collected, dried to form crude material • extraction process to purify to powder or liquid form • also contains chymopapain • Use: anti-inflammatory and digestive • meat tenderiser • breaks down tough meat fibres • long traditional use in S.American • teeth whitening agent • In some toothpastes • contact lens cleaner • jellyfish, bee/wasp stings, stingray wounds (home remedy) • breaks down protein toxins in the venom • wound debriding • digestive aid

4. Bromelain • One of two proteases • Stem bromelain • Fruit bromelain • History: • 1891 isolated • 1957 introduced as therapeutic supplement • 13th most widely used herbal medicine in Germany • Source: Bromeliaceae family • eg pineapple Ananas comosus – commerically from thestem • Thailand – after fruit harvesting stem stripped, crushed, pressed to get juice, concentrated • Use: meat tenderising • anti-inflammatory: sports injury, trauma, arthritis • digestive problems, phlebitis, sinusitis • platelet clumping, blood clots in arteries • A/E: may show cardiotonic activity (doses of up to 1840mg) • nausea, vomiting, diarrhoea, menorrhagia, possible allergenic reaction

5. Trypsin, Chymotrypsin • Serine proteases or endopeptidases – ‘proteolytic’ - hydrolyse peptide bonds • modify the electrostatic environment of the serine • chymotrypsin -> phenylalanine, tryptophan and tyrosine residues • trypsin -> aspartic acid residue (in catalytic pocket) which attracts and stabilises lysine and arginine • both have to be activated • inactive form trypsinogen • removal of hexapeptide from terminal end -> β-trypsin • further AA removal -> other forms eg α-trypsin • cystic fibrosis – trypsin deficiency • Source: bovine pancreas (purified) • crystallised from pancreatic juice • introduced as medicinals mid-20th century • ? dosage forms not available in US

6. Uses: (* modern, rest historical) • Topical* (ointment, dusts, dressing, gel capsule to insert into fistulas): • cleaning necrotic wounds • attack dead tissue • not living which has inhibitory enzymes • cleaning suppurating wounds • decreases pus • burns – reduces tissue destruction and free radical production • Oral: • with buccal tablets • pancreatic supplement • to dissolve blood clots (microbial form)* • combined with papain in many cancers to reduce disease and radiation/chemotherapy symptoms* • (in baby foods to pre-digest it*) • Inhalation (spray): to reduce tenacious sputum • I/M: anti-inflammatory (pancreatic form) • Injectable: • cataract and eye lens surgery* – ocular inflammation • phlebitis • traumatic wounds • Chymotrypsin • more anti-inflammatory activity • used for sporting wounds • C/I: liver disease, blood clotting

7. Pancreatin • Source: porcine pancreas • crude form used since before 1870 • Use: for reduced exocrine secretion • pancreatic enzyme supplements - pancrelipase • cystic fibrosis • pancreatectomy • chronic pancreatitis • pancreatic cancer (if obstructs outflow) • C/I: hypersensitivity to porcine products • Products: standardised for lipase, amylase and protease activity • fat, carbohydrate and protein digestion • Counselling: • inactivated by gastric acid • best taken with food (immediately before or after) • H2antagonists one hour before or concurrent antacids can reduce gastric acidity • no chewing enteric-coated preparations • inactivated by heat • avoid mixing with hot (temperature) food • adequate hydration with high-dose formulations

8. Pepsin • Source: porcine gastric muscosa • Use: (protease) • gastric hypochlorhydria • deficiency of gastric enzymes • dyspepsia • Diastase • Refers to α-,β-,γ-amylase • first discovered in 1833 in malt solution • Source: • Animal: eg porcine • Vegetable: mould (Aspergillus oryzae – taka-diastase), malt, bacteria • Action: catalyses breakdown of starch to maltose • Use: overindulgence in starchy foods • Pectinase • Action: refers to enzymes that break down pectin • polysaccharide substrate found in plant cell walls • eg polygalacturonase • Source: extracted from fungi • eg Aspergillus niger • Use: processing involving degradation of plant material • to speed up extraction of juice from fruit eg apples • retting – obtaining fibres of eg flax, jute, hemp

9. Urokinase • Source: isolated from human urine • Action: • convert plasminogen to plasmin which catalyses the breakdown of fibrin • Use: • deep vein thrombosis, pulmonary embolism • thrombosed IV cannulae, central venous catheters and haemodialysis shunts • peripheral arterial thromboembolism • A/E: bleeding, allergic reactions, cholesterol embolism • C/I: bleeding disorders, history of bleeding

10. Asparaginase • Source: isolated from E.coli • recombinant form expressed in the bacteria • Action: • catalyses the conversion of the AA L-asparagine to L-aspartic acid reducing availability of L-asparagine to leukaemic cells • Use: • ALL acute lymphoblastic leukaemia • some subtypes of non-Hodgkin’s lymphoma • A/E: allergy, pancreatitis, coagulopathy • C/I: previous allergic reaction to it, pancreatitis • Counselling: increase fluid intake and avoid dehydration

11. Hyaluronidase • Source: • buffalo leeches • leeches of the sub-family Hirudinariinae • eg Hirudinaria manillensis, Poecilobdella granulosa • ? sheep • now human recombinant • Action: degrades or hydrolyses hyaluronic acid • part of the interstitial barrier (connective tissue) • Use: speeds dispersion and delivery of drugs • ophthalmic surgery with local anaesthetics • renders tissues more easily permeable to injected fluids • eg by subcutaneous injection – hypodermoclysis • extravasation • (inadvertant leakage of the drug out of a vein into surrounding tissue)

12. Many other recombinants • Tissue plasminogen activator (tPA) • myocardial infarction, ischaemic stroke, certain pulmonary embolisms • DNA-ase • liquefy mucopurulent secretions in bronchopulmonary disease • from bovine pancreas in 1956 (dornase) • now recombinant human for cystic fibrosis • Imiglucerase • analog of human β-glucocerebrosidase • Type I Gaucher disease • N-acetyl-galactosamine-4-sulfase • mucopolysaccharadosis • Alpha-L-iduronidase • mucopolysaccharadosis I • α-glucosidase • Pompe disease (rare) • Alpha-1-antitrypsin • alpha-1-antitrypsin deficiency (emphysema, liver) • enzyme mixture – coeliac disease (gluten)