The effect of betel nut extract on cell growth and prostaglandin endoperoxide synthase in human epidermoid carcinoma cells.
The objective of this study was to find out whether prostaglandin endoperoxide synthase (PHS) involves the action of betel nut extract (BNE) on the growth of oral cancers. Therefore, growth and PHS activity were examined in two human oral carcinoma cell lines (OEC-M1 and KB) and one normal fibroblast cell line (NF) in the presence of increasing BNE concentration. BNE at concentrations above 50 microg/ml significantly inhibited the cell growth of OEC-M1 after 72 h in culture, of KB and NF after 48 h in culture. The IC50 of BNE in OEC-M1, KB and NF at 24 h in culture was about 406, 37.5 and 140 microg/ml respectively. PHS activity in OEC-M1 was significantly increased by low BNE concentrations (50 microg/ml, 114%; 100 microg/ml, 33%; 150 microg/ml, 30%) but significantly reduced at higher BNE concentrations (300 microg/ml, 33%; 500 microg/ml, 61%). The PHS activity in KB was significantly inhibited by BNE and this effect was intensified as concentrations increased (50 microg/ml, 31%; 100 microg/ml, 24%; 150 microg/ml, 43%; 300 microg/ml, 60%; 500 microg/ml, 92%). Similar to that in OEC-M1, the PHS activity in NF was significantly increased at low BNE concentrations (50 microg/ml, 139%; 100 microg/ml, 87%;150 microg/ml, 77%) but reduced at higher concentrations (300 microg/ml, 55%; 500 microg/ml, 72%). The PHS activity in all cell lines was almost completely blocked by indomethacin (5 x 10(-6) M). We conclude that these findings suggest that PHS may be an important biochemical mediator of the effect of BNE on the growth of two human oral carcinoma cell lines.
Yang
C Y
CY
Department of Dentistry, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, Republic of China.
Meng
C L
CL
van der Bijl
P
P
Lee
H K
HK
D016718:Arachidonic Acid / Q000378:metabolism; D001114:Areca / Q000009:adverse effects*; D002294:Carcinoma, Squamous Cell / Q000201:enzymology / Q000378:metabolism / Q000473:pathology*; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D016861:Cyclooxygenase Inhibitors; D015232:Dinoprostone / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D015777:Eicosanoids / Q000096:biosynthesis; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D005887:Gingival Neoplasms / Q000201:enzymology / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D007213:Indomethacin / Q000494:pharmacology; D020128:Inhibitory Concentration 50; D007624:KB Cells; D010936:Plant Extracts / Q000009:adverse effects; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism*
D016861:Cyclooxygenase Inhibitors; D015777:Eicosanoids; D010936:Plant Extracts; D016718:Arachidonic Acid; D011451:Prostaglandin-Endoperoxide Synthases; D015232:Dinoprostone; D007213:Indomethacin