Protective effects of EGCG on salivary gland cells treated with gamma-radiation or cis-platinum(II)diammine dichloride.
Dysfunction of salivary glands is often associated with aging and cancer therapy. Green tea polyphenols were previously found to protect normal epithelial cells from reactive oxygen species, and to induce apoptosis in tumor cells. The current study investigated whether -(-) epigallocatechin-3-gallate (EGCG), the major green tea polyphenol, protects normal salivary gland cells from the effects of gamma-irradiation and the chemotherapy drug cis-platinum(II)diammine dichloride (CDDP). Human immortalized salivary acinar and ductal cells, and oral squamous cell carcinoma cells were irradiated with gamma-rays or treated with CDDP, with or without pretreatment with EGCG, followed by MTT and BrdU incorporation assays. The results demonstrated that EGCG protected the normal salivary gland cells from chemical or irradiation-induced damage. However, protection of oral cancer cells by EGCG was also observed if EGCG was at physiologically achievable salivary concentrations but not at higher concentrations, suggesting that the combination of green tea consumption with cancer therapy requires further evaluation.
Yamamoto
Tetsuya
T
Department of Oral Biology and Maxillofacial Pathology, School of Dentistry, School of Medicine, Medical College of Georgia, Augusta, GA 30912, USA.
Staples
Jared
J
Wataha
John
J
Lewis
Jill
J
Lockwood
Petra
P
Schoenlein
Patricia
P
Rao
Sushma
S
Osaki
Tokio
T
Dickinson
Douglas
D
Kamatani
Takaaki
T
Schuster
George
G
Hsu
Stephen
S
D002294:Carcinoma, Squamous Cell / Q000378:metabolism / Q000532:radiotherapy; D002392:Catechin / Q000031:analogs & derivatives* / Q000494:pharmacology*; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects; D002945:Cisplatin / Q000009:adverse effects / Q000494:pharmacology; D056741:Cyclin D; D051358:Cyclin-Dependent Kinase 4; D050759:Cyclin-Dependent Kinase Inhibitor p21; D018844:Cyclin-Dependent Kinases / Q000378:metabolism; D016213:Cyclins / Q000378:metabolism; D004247:DNA / Q000096:biosynthesis; D004305:Dose-Response Relationship, Drug; D004307:Dose-Response Relationship, Radiation; D005720:Gamma Rays; D006801:Humans; D009062:Mouth Neoplasms / Q000378:metabolism / Q000532:radiotherapy; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D011832:Radiation Injuries / Q000209:etiology / Q000517:prevention & control*; D011837:Radiation-Protective Agents / Q000494:pharmacology*; D012469:Salivary Glands / Q000187:drug effects* / Q000378:metabolism / Q000528:radiation effects*; D013778:Tetrazolium Salts; D013844:Thiazoles
C493956:CDKN1A protein, human; D056741:Cyclin D; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D011518:Proto-Oncogene Proteins; D011837:Radiation-Protective Agents; D013778:Tetrazolium Salts; D013844:Thiazoles; D002392:Catechin; D004247:DNA; C045651:epigallocatechin gallate; C495900:CDK4 protein, human; D051358:Cyclin-Dependent Kinase 4; D018844:Cyclin-Dependent Kinases; C022616:thiazolyl blue; D002945:Cisplatin