Norcantharidin reduced cyclins and cytokines production in human peripheral blood mononuclear cells.
OBJECTIVE
To evaluate potential agents of therapeutic value in tissue inflammation, we studied norcantharidin (NCTD) and its derivatives for their effects on immune responses of human peripheral blood mononuclear cells (PBMC) in vitro.


METHODS
PBMC proliferation was evaluated by tritiated thymidine uptake method. The production and gene expression of cytokines were determined with enzyme immunoassays (EIA) and reverse transcription-polymerase chain reaction (RT-PCR), respectively.


RESULTS
Five derivatives from NCTD had no significant effect on cell proliferation in PBMC. NCTD inhibited PBMC proliferation induced by phytohemagglutinin (PHA) with a 50% inhibitory concentration (IC(50)) 42.1+/-2.3 microM. The inhibitory action of NCTD did not involve direct cytotoxicity. To localize the point in the PBMC proliferation where arrest occurred, a set of key regulatory events leading to the cell proliferation, including cell cycle progression, production and gene expression of interleukin-2 (IL-2), IL-4, IL-10, and interferon-gamma (IFN-gamma) and cyclins was examined. Data demonstrated NCTD arrested the cell cycle progression of activated PBMC from the G1 transition to the S phase. The cyclin D3, E, A, and B transcripts and protein production in PHA-treated PBMC was reduced by NCTD. Whereas NCTD exerted no effect on IL-4 and IFN-gamma production, it significantly alleviated the production and mRNA expression of IL-2 and IL-10 in activated PBMC.


CONCLUSIONS
The suppressant effects of NCTD on proliferation of PBMC activated by PHA therefore appear to be mediated, at least in part, through inhibition of cyclins and IL-2 production and arrest of cell cycle progression in the cells.
Chen
Yi-Chun
YC
Institute of Pharmacology, National Yang-Ming University, Taiwan, ROC.
Chang
Shi-Chuan
SC
Wu
Ming-Hsi
MH
Chuang
Kai-An
KA
Wu
Jin-Yi
JY
Tsai
Wei-Jern
WJ
Kuo
Yuh-Chi
YC
D000328:Adult; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000494:pharmacology*; D002453:Cell Cycle / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D016213:Cyclins / Q000096:biosynthesis* / Q000235:genetics; D016207:Cytokines / Q000096:biosynthesis* / Q000235:genetics; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D010835:Phytohemagglutinins / Q000494:pharmacology; D012333:RNA, Messenger / Q000032:analysis
D019086:Bridged Bicyclo Compounds, Heterocyclic; D016213:Cyclins; D016207:Cytokines; D010835:Phytohemagglutinins; D012333:RNA, Messenger; C069741:norcantharidin