[Antioxidant treatment with N-acetylcysteine and vitamin C in patients with chronic bronchitis].
OBJECTIVE
N-acetylcysteine (NAC) is known to have direct antioxidant properties due to its thiol-group on the one hand as well as indirect antioxidant capacity as cysteine-donor to cellular glutathione-synthesis on the other hand. Therefore NAC appears to be attractive in antioxidant therapy of inflammatory disorders of the lung. This study aimed to investigate the use of antioxidant therapy with NAC in chronic bronchitis.


METHODS
In this randomized, double-blinded and placebo-controlled trial 100 patients divided into four groups were observed over a period of 3 months. The treatment consisted of either 600 mg NAC bid, 500 mg Vitamin C bid, a combination of those two substances using the same dosage or a placebo-preparation. The release of reactive oxygen species from isolated neutrophilic granulocytes and mononuclear cells was quantified before treatment and after three months using chemiluminescence (primary outcome parameter). Furthermore cellular glutathione content of these inflammatory cells was quantified spectrometrically. In addition, leukocyte-count and erythrocyte sedimentation rate as well as spirometry and a standardized symptom-based questionnaire were used to monitor the clinical efficacy.


RESULTS
None of the above substances were able to significantly reduce the release of reactive oxygen species from the examined population of inflammatory cells. They also failed to increase intracellular glutathione-levels. Concordantly, no changes in spirometry and the results of the symptom-based questionnaire were found.


CONCLUSIONS
In summary NAC, Vitamin C and the NAC/ Vitamin C-combination did neither enhance antioxidant protection in the blood nor is it of any clinical benefit in chronic bronchitis. Possible reasons may be a lack of antioxidant deficiency in these patients and negative feedback mechanisms of the glutathione-system.
Lukas
R
R
Abteilung für Pneumologie, Allergologie und Schlafmedizin, Berufsgenossenschaftliche Kliniken Bergmannsheil, Universitätsklinik der Ruhr-Universität Bochum.
Schärling
B
B
Schultze-Werninghaus
G
G
Gillissen
A
A
D000111:Acetylcysteine / Q000627:therapeutic use*; D000975:Antioxidants / Q000627:therapeutic use*; D001205:Ascorbic Acid / Q000627:therapeutic use*; D001799:Blood Sedimentation; D029481:Bronchitis, Chronic / Q000188:drug therapy* / Q000378:metabolism; D004311:Double-Blind Method; D004359:Drug Therapy, Combination; D005260:Female; D016166:Free Radical Scavengers / Q000627:therapeutic use*; D005978:Glutathione / Q000097:blood; D006801:Humans; D007958:Leukocyte Count; D007963:Leukocytes, Mononuclear / Q000187:drug effects / Q000378:metabolism; D008163:Luminescent Measurements; D008297:Male; D008875:Middle Aged; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D013147:Spirometry; D011795:Surveys and Questionnaires; D017211:Treatment Failure
D000975:Antioxidants; D016166:Free Radical Scavengers; D017382:Reactive Oxygen Species; D005978:Glutathione; D001205:Ascorbic Acid; D000111:Acetylcysteine