Effects of sulphurous water on human neutrophil elastase release.
BACKGROUND
Molecules bearing a sulphide (HS) group, such as glutathione, play a fundamental role in the defensive system of human airways, as shown by the fact that the lining fluid covering the epithelia of the respiratory tract contains very high concentrations of glutathione: the lungs and nose, respectively, contain about 140 and 40 times the concentrations found in plasma. Consequently, various low-weight soluble molecules bearing an HS group (including N-acetylcysteine, mesna and thiopronine, and prodrugs such as stepronine and erdosteine) have been used for therapeutic purposes. HS groups can also be therapeutically administered by means of sulphurous thermal water containing HS groups. The aim of this study was to investigate the direct activity of such water on the release of elastase by activated human neutrophils.


METHODS
After the neutrophils were incubated with increasing amounts of sulphurous water or the HS/hydrogen sulphide donor sodium hydrosulphide (NaHS), elastase release was initiated by N-formyl-methionyl-leucyl-phenylalanine and measured by means of spectrofluorimetry using methylsuccinylalanylprolylvalyl-methylcoumarin amide as the fluorogenic substrate. To verify the presence of direct action on elastase we determined the diameter of the area of elastinolysis on elastine-agarose gel plates.


RESULTS
The sulphurous water significantly inhibited elastase release at HS concentrations ranging from 4.5 to 18 μg/ml, as assayed using the iodometric method; in the case of NaHS, the inhibition was significant at HS concentrations ranging from 2.2 to 18 μg/ml. The concentration-effect regression lines of both were parallel and neither showed any direct elastolytic activity.


CONCLUSIONS
Previous claims concerning the activity of sulphurous water have been based on the patients' subjective sense of wellbeing and on symptomatic (or general) clinical improvements that are not easy to define or quantify exactly. Our findings indicate that, in addition to its known mucolytic and antioxidant activity, sulphurous water also has an anti-elastase activity that may help to control the inflammatory processes of upper and lower airway diseases.
Braga
Pier Carlo
PC
Center of Respiratory Pharmacology, Department of Pharmacology, School of Medicine, University of Milan, Via Vanvitelli 32, 20129 Milan, Italy. piercarlo.braga@unimi.It
Dal Sasso
Monica
M
Culici
Maria
M
Spallino
Alessandra
A
Marabini
Laura
L
Bianchi
Tiziana
T
Nappi
Giuseppe
G
D000328:Adult; D045482:Hot Springs; D006801:Humans; D008900:Mineral Waters; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D009504:Neutrophils / Q000187:drug effects* / Q000378:metabolism; D010196:Pancreatic Elastase / Q000378:metabolism*; D013050:Spectrometry, Fluorescence; D013438:Sulfhydryl Compounds / Q000008:administration & dosage / Q000494:pharmacology*
D008900:Mineral Waters; D013438:Sulfhydryl Compounds; D009240:N-Formylmethionine Leucyl-Phenylalanine; D010196:Pancreatic Elastase