Inhibition of Elastase and Collagenase by Anti-Inflammatory Drugs

Abstract

Polymorphonuclear leukocytic granules contain elastase and collagenase activities, both of which may be involved in the lysis of vascular basement membranes at physiologic pH ( 1 , 2 ) and, therefore, related to the pathogenesis of vasculitis (2). Abnormally high levels of collagenase are found in synoviocytes of patients with rheumatoid arthritis in tissue culture; levels of the latter correlate positively with the severity of the disease ( 3 ) . Collagenase or elastase inhibitors are, therefore, of potential therapeutic utility, especially since these may attenuate the development or perpetuation of connective tissue diseases. The purpose of this report is to describe the effects of currently used antiinflammatory agents on crystalline pancreatic elastase and C. histolyticum collagenase, both of which are similar to the abovementioned leukocytic or synovial enzymes.Materials and Methods. Achilles tendon collagen and chromatographically purified collagenase (C. histolyticum) were purchased from Worthington Biochemical Corporation. Twice-crystallized pancreatic elastase (porcine) and elastin-orcein were obtained from Sigma Chemical C,ompany. Collagenase was assayed by incubating 2 pg of enzyme and 25 mg collagen in 0.025 IM Tris-HC1 buffer, pH 8.0, with or without drugs for 20 hr at 37", followed by filtration through Whatman No.40 filter paper. The total reaction volume was 3.0 ml; test tubes were covered with parafilm to avoid evaporation. The filtrate (0.2 ml) was assayed for liberation of amino acids by the ninhydrin procedure of Moore and Stein (4) ; leucine was employed as a reference amino acid. Blank (no enzyme) and control (enzyme, no drug) absorbance values were, respectively, 0.126 & .005 ( n = 15) and 0.611 t .0826 ( n = 2 2 ) . Collagenase (4 Lozdsiana 70112 pg) was also assayed using 20 mg of insoluble diazotized collagen (azocoll, Calbiochem) as substrate in 2.0 ml 0.025 M Tris-HC1 buffer, pH 8.0, 37', for 30 min followed by addition of 3.0 ml distilled water and filtration through Whatman No. 40 filter paper.Absorbance was determined at 520 mp. Elastase activity was measured by incubating 0.1 mg/ml enzyme in a 2.0-ml total reaction volume containing 20 mg elastin-orcein and 0.025 M Tris-HC1 buffer, pH 8.0, with or without drugs for 60 min at 37". Reaction was terminated by addition of 3.0 ml distilled water followed by filtration through Whatman No. 40 or 43 filter paper. Absorbance was determined at 590 mp. Blank (no enzyme) and control (enzyme, no drug) absorbance values were, respectively, 0.027 t .002 ( n = 3) and 0.204 t .006 ( n = 9). Drug solutions were prepared by dissolution in a small amount of 1.0 N sodium hydroxide, dilution to slightly less than 50 ml, neutralization with 1.0 N hydrochloric acid, and final dilution in 0.05 M Tris-HC1 buffer, pH 8.0, to yield the final drug solution a t p H 8.0 in 0.025 M Tris buffer. Addition of sodium hydroxide did not appreciably aid the dissolution of cortisone acetate or dexamethasone. Thus, the latter drugs were slowly triturated into solution. T...

Perspectives in Nonsteroidal Anti‐inflammatory Agents

“…An o-substituted phenoxyacetic acid with structure features resembling an open-chain analog of indomethacin is clamidoxic acid (20) [I6].…”