[Inhibitory effect of sinomenine on expression of cyclooxygenase-2 in lipopolysaccharide-induced PC-12 cells].
OBJECTIVE
To study the effects of sinomenine (Sin) on cell proliferation, intracellular expression of cyclooxygenase-2 (COX-2), and production of PGE2 in lipopolysaccharide-induced PC-12 cells, To explore the Sin's mechanism on nerve cell.


METHODS
PC-12 cells were cultured with nerve growing factors (NGF), and pretreated with Sin at various concentrations (0, 3 x 10(-6), 30 x 10(-6), 150 x 10(-6) mol x L(-1)) for 2 hours, then with or without stimulation of lipopolysaccharide (LPS). The proliferation activity of PC-12 cells was determined by 3H-TdR incorporation, and the production of PGE2 in culture supernatants of PC-12 cells was detected with competitive ELISA. Expression of COX-2 mRNA in PC-12 cells was analyzed by semi-quantitative RT-PCR, and expression of COX-2 protein was estimated by Western blot method and cellular enzyme immunoassay. Nuclear factor-kappa B (NF-kappaB) activity in whole-cell extract of PC-12 cells was also measured by an ELISA-based method.


RESULTS
The data showed that Sin down-regulated the expression of COX-2 mRNA and protein, and reduced the production of PGE2 in the LPS-stimulated PC-12 cells which correlated with Sin's concentrations positively. In addition, NF-kappaB activity in LPS-stimulated cells was suppressed significantly by Sin. No inhibition of proliferation of PC-12 cells due to Sin treatment was observed.


CONCLUSIONS
Sin mediates the down-regulation of expression of COX-2 and production of induced PGE2 in PC-12 cells by suppressing the activity of NF-kappaB.
Chen
Wei
W
Department of Psychiatry, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou 310016, China. cc0731@hzcnc.com
Shen
Yue-di
YD
Zhao
Guang-shu
GS
Yao
Hang-ping
HP
D000818:Animals; D049109:Cell Proliferation / Q000187:drug effects; D051546:Cyclooxygenase 2; D015232:Dinoprostone / Q000096:biosynthesis; D015536:Down-Regulation; D008070:Lipopolysaccharides; D009019:Morphinans / Q000302:isolation & purification / Q000494:pharmacology*; D016328:NF-kappa B / Q000378:metabolism; D016716:PC12 Cells; D010946:Plants, Medicinal / Q000737:chemistry; D011451:Prostaglandin-Endoperoxide Synthases / Q000096:biosynthesis* / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D051381:Rats; D032841:Sinomenium / Q000737:chemistry
D008070:Lipopolysaccharides; D009019:Morphinans; D016328:NF-kappa B; D012333:RNA, Messenger; C009271:sinomenine; D051546:Cyclooxygenase 2; D011451:Prostaglandin-Endoperoxide Synthases; D015232:Dinoprostone