Antimicrobial compositions

Abstract

Storage-stable compositions for generating antimicrobial activity are described. The compositions comprise an enzyme that is able to convert a substrate to release hydrogen peroxide, and an unrefined natural substance, such as a honey, that includes a substrate for the enzyme. In certain embodiments, the enzyme is a purified enzyme. In other embodiments, the substrate lacks catalase activity, and the enzyme is additional to any enzyme activity able to convert the substrate to release hydrogen peroxide that may be present in the unrefined natural substance. The storage-stable compositions do not include sufficient free water to allow the enzyme to convert the substrate. Use of the compositions to treat microbial infections and wounds is described, as well as methods for their production.

1 . A storage-stable composition for generating antimicrobial activity, which comprises:
 a purified enzyme that is able to convert a substrate to release hydrogen peroxide; and   an unrefined natural substance that includes a substrate for the enzyme;   
       wherein the composition does not include sufficient free water to allow the enzyme to convert the substrate. 
     
     
         2 . A storage-stable composition for generating antimicrobial activity, which comprises:
 an enzyme that is able to convert a substrate to release hydrogen peroxide; and   an unrefined natural substance that lacks catalase activity and that includes a substrate for the enzyme;   
       wherein the enzyme is additional to any enzyme activity able to convert the substrate to release hydrogen peroxide that may be present in the unrefined natural substance, and the composition does not include sufficient free water to allow the enzyme to convert the substrate. 
     
     
         3 . A composition according to  claim 1 , wherein the unrefined natural substance lacks catalase activity. 
     
     
         4 . A composition according to  claim 2  or  3 , wherein the substance has been treated to remove or inactivate catalase activity. 
     
     
         5 . A composition according to any preceding claim, wherein the substance is an unrefined natural sugar substance. 
     
     
         6 . A composition according to  claim 5 , wherein the sugar substance is a honey. 
     
     
         7 . A composition according to  claim 5 , wherein the sugar substance is a honey that has been treated to remove or inactivate catalase activity. 
     
     
         8 . A composition according to  claim 5 , wherein the sugar substance is a syrup, or an inverted syrup. 
     
     
         9 . A composition according to any preceding claim, wherein the substance lacks enzyme activity that is able to convert the substrate to release hydrogen peroxide. 
     
     
         10 . A composition according to any preceding claim, wherein the substance is a pasteurised substance. 
     
     
         11 . A composition according to  claim 6 , wherein the honey is an unpasteurised honery, preferably a creamed unpasteurised honey. 
     
     
         12 . A composition according to any preceding claim, wherein the enzyme is an oxidoreductase enzyme. 
     
     
         13 . A composition according to  claim 12 , wherein the oxidoreductase enzyme is a glucose oxidase, hexose oxidase, cholesterol oxidase, galactose oxidase, pyranose oxidase, choline oxidase, pyruvate oxidase, glycollate oxidase, or amioacid oxidase. 
     
     
         14 . A composition according to  claim 13 , wherein the substrate for the oxidoreductase enzyme is D-glucose, hexose, cholesterol, D-galactose, pyranose, choline, pyruvate, glycollate or aminoacid. 
     
     
         15 . A composition according to  claim 13 , wherein the oxidoreductase enzyme is glucose oxidase and the substrate for the oxidoreductase enzyme is D-glucose. 
     
     
         16 . A composition according to  claim 15 , wherein the composition includes at least one unit of glucose oxidase per gram of the composition. 
     
     
         17 . A composition according to  claim 16 , wherein the composition comprises up to 1500 units of glucose oxidase per gram of the composition. 
     
     
         18 . A composition according to  claim 16  or  17 , wherein the composition comprises more than 15 units of glucose oxidase per gram of the composition. 
     
     
         19 . A composition according to any of  claims 16  to  18 , wherein the composition comprises at least 100 units, and preferably 100-500 units, of glucose oxidase per gram of the composition. 
     
     
         20 . A composition according to any of  claims 16  to  19 , wherein the composition comprises at least 500 units, and preferably 500-1000 units, of glucose oxidase per gram of the composition. 
     
     
         21 . A composition according to any preceding claim which is a food standard composition. 
     
     
         22 . A composition according to any preceding claim, which is a medical grade or medical device grade composition. 
     
     
         23 . A composition according to any preceding claim, wherein each of the components of the composition are natural substances. 
     
     
         24 . A composition according to any preceding claim in the form of a powder. 
     
     
         25 . An antimicrobial composition which comprises a composition according to any of  claims 1  to  24  diluted with sufficient water to allow release of hydrogen peroxide by conversion of the substrate by the enzyme. 
     
     
         26 . A composition for generating antimicrobial activity, which comprises: an unrefined natural substance; and a purified enzyme that is able to convert a substrate in the unrefined natural substance to release hydrogen peroxide. 
     
     
         27 . A composition for generating antimicrobial activity, which comprises: an unrefined natural substance that lacks catalase activity; and an enzyme that is able to convert a substrate in the unrefined natural substance to release hydrogen peroxide, wherein the enzyme is additional to any enzyme activity able to convert the substrate to release hydrogen peroxide that may be present in the unrefined natural substance. 
     
     
         28 . A composition according to  claim 26 , wherein the unrefined natural substance lacks catalase activity. 
     
     
         29 . A composition according to any of  claims 26  to  28 , which further comprises hydrogen peroxide. 
     
     
         30 . A composition according to any preceding claim, which is a sterile composition. 
     
     
         31 . A composition according to  claim 30 , which has been sterilised by exposure to gamma irradiation. 
     
     
         32 . An antimicrobial solution, which comprises a composition according to any of  claims 26  to  31 . 
     
     
         33 . A method of sterilising a composition according to any of  claims 1  to  29 , which comprises exposing the composition to gamma irradiation, preferably 10-70 kGy, more preferably 25-70 kGy, most preferably 35-70 kGy. 
     
     
         34 . A method for producing a storage-stable composition for generating antimicrobial activity, which comprises: contacting a purified enzyme that is able to convert a substrate to release hydrogen peroxide with an unrefined natural substance that includes a substrate for the enzyme, wherein the composition does not include sufficient free water to allow the enzyme to convert the substrate. 
     
     
         35 . A method for producing a storage-stable composition for generating antimicrobial activity, which comprises: contacting an enzyme that is able to convert a substrate to release hydrogen peroxide with an unrefined natural substance that lacks catalase activity and that includes a substrate for the enzyme, wherein the composition does not include sufficient free water to allow the enzyme to convert the substrate. 
     
     
         36 . A method according to  claim 34 , wherein the unrefined natural substance lacks catalase activity. 
     
     
         37 . A method according to any of  claims 34  to  36 , wherein the substance is an unrefined natural sugar substance. 
     
     
         38 . A method according to any of  claims 34  to  37 , wherein the substance has been treated to remove or inactivate catalase activity present in the substance and/or any enzyme activity present in the substance that is able to convert the substrate to release hydrogen peroxide, prior to contacting the substance with the enzyme. 
     
     
         39 . A method according to  claim 38 , which further comprises treating the substance to remove or inactivate catalase activity and/or substrate conversion enzyme activity present in the substance, prior to contacting the substance with the enzyme. 
     
     
         40 . A method according to  claim 39 , wherein the substance is treated by heating the substance to inactivate catalase and/or substrate conversion activity, and then cooling the substance, prior to contacting the substance with the enzyme, to a temperature that allows retention of activity of the enzyme. 
     
     
         41 . A method according to any of  claims 34  to  40 , wherein the substance is a honey. 
     
     
         42 . A method according to  claim 37 , wherein the unrefined natural sugar substance is a syrup or an inverted syrup. 
     
     
         43 . A method according to  claim 42 , which further comprises inverting a substance that comprises sucrose to form the inverted syrup. 
     
     
         44 . A method according to any of  claims 34  to  43 , wherein the enzyme is an oxidoreductase enzyme. 
     
     
         45 . A method according to  claim 44 , wherein the oxidoreductase enzyme is a glucose oxidase, hexose oxidase, cholesterol oxidase, galactose oxidase, pyranose oxidase, choline oxidase, pyruvate oxidase, glycollate oxidase, or amioacid oxidase. 
     
     
         46 . A method according to  claim 45 , wherein the substrate for the oxidoreductase enzyme is D-glucose, hexose, cholesterol, D-galactose, pyranose, choline, pyruvate, glycollate or aminoacid. 
     
     
         47 . A method according to  claim 44 , wherein the oxidoreductase enzyme is glucose oxidase and the substrate for the oxidoreductase enzyme is D-glucose. 
     
     
         48 . A method according to any of  claims 34  to  47  for producing a food standard composition, wherein the substance and the enzyme are of food standard. 
     
     
         49 . A method according to any of  claims 34  to  48 , wherein each of the components of the composition are natural substances. 
     
     
         50 . A method for producing a composition for generating antimicrobial activity, which comprises: contacting a purified enzyme that is able to convert a substrate to release hydrogen peroxide with an unrefined natural substance that includes a substrate for the enzyme. 
     
     
         51 . A method for producing a composition for generating antimicrobial activity, which comprises: contacting an enzyme that is able to convert a substrate to release hydrogen peroxide with an unrefined natural substance that lacks catalase activity and that includes a substrate for the enzyme. 
     
     
         52 . A method according to  claim 50 , wherein the unrefined natural substance lacks catalase activity. 
     
     
         53 . A method according to any of  claims 34  to  52 , wherein the enzyme and the unrefined natural substance are in powder form. 
     
     
         54 . A method for producing an antimicrobial solution, which comprises diluting a storage-stable antimicrobial composition according to any of  claims 1  to  24  with sufficient water to allow the enzyme to convert the substrate in the sugar substance and release hydrogen peroxide. 
     
     
         55 . A composition according to any of  claims 1  to  31 , or an antimicrobial solution according to  claim 32 , for use as a medicament. 
     
     
         56 . A composition according to any of  claims 1  to  31 , or an antimicrobial solution according to  claim 32 , for prevention, treatment, or amelioration of a microbial infection. 
     
     
         57 . Use of a composition according to any of  claims 1  to  31 , or an antimicrobial solution according to  claim 32 , in the manufacture of a medicament for the prevention, treatment, or amelioration of a microbial infection. 
     
     
         58 . A method of preventing, treating, or ameliorating a microbial infection, which comprises administering a composition according to any of  claims 1  to  31 , or an antimicrobial solution according to  claim 32 , to a subject in need of such prevention, treatment or amelioration. 
     
     
         59 . A method according to  claim 58 , which comprises topically administering the composition or solution. 
     
     
         60 . A use or method according to any of  claims 55  to  59 , for treating a human or an animal subject. 
     
     
         61 . A method of treating a wound, which comprises administering a composition according to any of  claims 1  to  31 , or an antimicrobial solution according to  claim 32 , to a wound site. 
     
     
         62 . A composition according to any of  claims 1  to  31 , or an antimicrobial solution according to  claim 32 , for treatment of a wound. 
     
     
         63 . Use of a composition according to any of  claims 1  to  31 , or an antimicrobial solution according to  claim 32 , in the manufacture of a medicament for treatment of a wound. 
     
     
         64 . A method of treating inflammation, which comprises administering a composition according to any of  claims 1  to  31 , or an antimicrobial solution according to  claim 32 , to a site of inflammation. 
     
     
         65 . A composition according to any of  claims 1  to  31 , or an antimicrobial solution according to  claim 32 , for treatment of inflammation. 
     
     
         66 . Use of a composition according to any of  claims 1  to  31 , or an antimicrobial solution according to  claim 32 , in the manufacture of a medicament for treatment of inflammation. 
     
     
         67 . A method of stimulating tissue growth, which comprises administering a composition according to any of  claims 1  to  31 , or an antimicrobial solution according to  claim 32 , to a site in need of such stimulation. 
     
     
         68 . A composition according to any of  claims 1  to  31 , or an antimicrobial solution according to  claim 32 , for stimulating tissue growth. 
     
     
         69 . Use of a composition according to any of  claims 1  to  31 , or an antimicrobial solution according to  claim 32 , in the manufacture of a medicament for stimulating tissue growth. 
     
     
         70 . A method of debriding a wound, which comprises administering a composition according to any of  claims 1  to  31 , or an antimicrobial solution according to  claim 32 , to a wound in need of debridement. 
     
     
         71 . A composition according to any of  claims 1  to  31 , or an antimicrobial solution according to  claim 32 , for debriding a wound. 
     
     
         72 . Use of a composition according to any of  claims 1  to  31 , or an antimicrobial solution according to  claim 32 , in the manufacture of a medicament for debriding a wound. 
     
     
         73 . A method of deodorising a wound, which comprises administering a composition according to any of  claims 1  to  31 , or an antimicrobial solution according to  claim 32 , to a wound in need of deodorising. 
     
     
         74 . A composition according to any of  claims 1  to  31 , or an antimicrobial solution according to  claim 32 , for deodorising a wound. 
     
     
         75 . Use of a composition according to any of  claims 1  to  31 , or an antimicrobial solution according to  claim 32 , in the manufacture of a medicament for deodorising a wound. 
     
     
         76 . A method according to  claim 58 , wherein the subject is an insect. 
     
     
         77 . A method according to  claim 76 , wherein the insect is a bee. 
     
     
         78 . A method according to  claim 77  for prevention, treatment, or amelioration of a  Nosema  infection. 
     
     
         79 . A pharmaceutical composition comprising a composition according to any of  claims 1  to  31 , or an antimicrobial solution according to  claim 32 , together with a pharmaceutically acceptable carrier, excipient, or diluent. 
     
     
         80 . A pharmaceutical composition according to  claim 79 , wherein the composition is sterile. 
     
     
         81 . A pharmaceutical composition according to  claim 79  or  80 , which is a medical grade, or medical device grade pharmaceutical composition. 
     
     
         82 . A wound dressing which comprises a dressing material for dressing a wound, and a composition according to any of  claims 1  to  31 , or an antimicrobial solution according to  claim 32 . 
     
     
         83 . An antimicrobial composition adapted for topical administration to a subject, which comprises a composition according to any of  claims 1  to  31 , or an antimicrobial solution according to  claim 32 . 
     
     
         84 . An antimicrobial composition adapted for oral administration to a subject, which comprises a composition according to any of  claims 1  to  31 , or an antimicrobial solution according to  claim 32 . 
     
     
         85 . A kit which comprises a composition according to any of  claims 1  to  31 , or a solution according to  claim 32 , and instructions for administering the composition. 
     
     
         86 . A method for preventing or inhibiting microbial growth, with comprises applying a composition according to any of  claims 1  to  31 , or an antimicrobial solution according to  claim 32 , to a surface or region where it is desired to prevent or inhibit such growth. 
     
     
         87 . A method according to  claim 86 , which comprises applying the composition or solution to prevent or inhibit growth of a plant or insect pathogen. 
     
     
         88 . A method according to  claim 86  or  87 , which comprises applying the composition or solution to prevent or inhibit growth of  Erwinia.    
     
     
         89 . A method according to any of  claims 86  to  88 , which comprises applying the composition or solution to a plant, a fruit, or a vegetable. 
     
     
         90 . A method according to  claim 89 , wherein the vegetable is a potato. 
     
     
         91 . Use of a composition according to any of  claims 1  to  31 , or an antimicrobial solution according to  claim 32 , to prevent or inhibit microbial growth.