Silybin inhibition of human T-lymphocyte activation.
Silybin, a 3-oxyflavone occurring in the thistle Silybum marianum, displays a dose-dependent inhibition of in-vitro lymphocyte blastogenesis induced by lectins (phytohaemagglutinin, Concanavalin A and pokeweed) and by anti-CD3 monoclonal antibody. The drug has no effect on cell viability and spontaneous 3H-thymidine incorporation, suggesting that the inhibitory activity is not due to aspecific toxicity. Since all the T-cell responses investigated require cell-membrane-associated events, the effect of silybin is probably at the level of the cell membrane, as for other flavonoids. Addition of CuSO4 prevents the inhibitory activity of silybin on PHA-induced proliferative response, indicating that the drug could exert its activity also by virtue of a chelation mechanism.
Meroni
P L
PL
Institute of Internal Medicine, Infectious Diseases and Immunopathology, University of Milan, Italy.
Barcellini
W
W
Borghi
M O
MO
Vismara
A
A
Ferraro
G
G
Ciani
D
D
Zanussi
C
C
D000911:Antibodies, Monoclonal / Q000276:immunology; D002478:Cells, Cultured; D003300:Copper / Q000494:pharmacology; D004247:DNA / Q000096:biosynthesis; D005419:Flavonoids / Q000494:pharmacology*; D006801:Humans; D037102:Lectins / Q000037:antagonists & inhibitors; D008213:Lymphocyte Activation / Q000187:drug effects; D012838:Silymarin / Q000494:pharmacology*; D013601:T-Lymphocytes / Q000187:drug effects*; D013936:Thymidine / Q000378:metabolism
D000911:Antibodies, Monoclonal; D005419:Flavonoids; D037102:Lectins; D012838:Silymarin; D003300:Copper; D004247:DNA; D013936:Thymidine