Immunosuppressive and cytotoxic effects of furosemide on human peripheral blood mononuclear cells.
BACKGROUND
We have previously shown that children with mild asthma have a modest improvement in their pulmonary function tests after aerosolized furosemide. The mechanism of action is not known. The observation that furosemide possesses a similar profile of protection as sodium cromoglycate and nedocromil sodium suggests that furosemide may inhibit mediator production and release.


OBJECTIVE
We studied the in vitro effects of furosemide on cytokine release from normal human peripheral blood mononuclear cells (PBMC) induced by E. coli lipopolysaccharide (LPS).


METHODS
Peripheral blood mononuclear cells were isolated by density gradient centrifugation, stimulated with LPS and incubated at 37 degrees C with varying concentrations of furosemide, hydrocortisone, sodium cromoglycate, and nedocromil sodium for 24 hours. Supernatants were extracted and study for levels of tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), and interleukin-8 (IL-8). Intracellular IL-6 and TNF-alpha concentrations were also measured by cell cytometry. Cell viability was examined using XTT cell proliferation test and-measuring the release of lactate dehydrogenase (LDH).


RESULTS
There was a significant reduction in levels of TNF-alpha and IL-6 at a furosemide concentration of 0.5 x 10(-2) M and a reduction in IL-8 levels at 10(-2) M. This inhibition was comparable to that found with equivalent molar concentrations of hydrocortisone. These findings were also confirmed with measurements of intracellular IL-6 and TNF-alpha by cell cytometry. High concentration of furosemide at 10(-2) M caused significant cellular cytotoxicity.


CONCLUSIONS
These data suggest that furosemide may exhibit an anti-inflammatory effect. Specifically, the addition of furosemide resulted in decreased production of cytokines. This effect may be due to an immunosuppressive activity on monocytes as well as a direct cytotoxic effect at high furosemide concentrations.
Yuengsrigul
A
A
Department of Pediatrics, Memorial Miller Children's Hospital, University of California, Irvine, USA.
Chin
T W
TW
Nussbaum
E
E
D018927:Anti-Asthmatic Agents / Q000494:pharmacology; D002455:Cell Division / Q000187:drug effects / Q000276:immunology; D002470:Cell Survival / Q000187:drug effects; D016207:Cytokines / Q000187:drug effects / Q000378:metabolism; D004232:Diuretics / Q000276:immunology / Q000633:toxicity; D005434:Flow Cytometry; D005665:Furosemide / Q000276:immunology* / Q000633:toxicity; D006801:Humans; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D015850:Interleukin-6 / Q000378:metabolism; D016209:Interleukin-8 / Q000378:metabolism; D007424:Intracellular Fluid / Q000737:chemistry; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D013194:Staining and Labeling; D014409:Tumor Necrosis Factor-alpha / Q000187:drug effects / Q000378:metabolism
D018927:Anti-Asthmatic Agents; D016207:Cytokines; D004232:Diuretics; D007166:Immunosuppressive Agents; D015850:Interleukin-6; D016209:Interleukin-8; D014409:Tumor Necrosis Factor-alpha; D005665:Furosemide