title: Efficacies of tea components on doxorubicin induced antitumor activity and reversal of multidrug resistance.
abstract: Considering of novel biochemical modulation by some foods and beverages, we have performed screening for green tea components that have enhancing effects on doxorubicin (DOX) induced antitumor activity. Components, such as caffeine, theanine, (-)-epigallocatechin gallate (EGCG) and flavonoids have inhibitory effects on the DOX efflux from Ehrlich ascites carcinoma cells. Thus, it is suggested that EGCG and flavonoids may enhance DOX induced antitumor activity and increase the DOX concentrations in tumors through the inhibition of DOX efflux. It is expected that these components in green tea exhibit low toxicity and that there are few side effects of drinking green tea in combination with an antitumor agent. We think that the intake of a favorite beverage favors a positive mental attitude of a patient and increases the efficacy of the chemotherapeutic index, and that this efficacy is useful for improving the quality of life on cancer chemotherapy. In DOX resistant P388 leukemia cell bearing mice theanine increased the DOX induced efficacy through an increase in the DOX concentrations in the tumors. Theanine attacked the same transport process for DOX in both types of cells, elevated the DOX concentration and increased the DOX induced antitumor activity.
authors.affiliation: School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Shizuoka, Japan. sadzuka@ys7.u-shizuoka-ken.ac.jp
authors.forename: Y
authors.initials: Y
authors.lastname: Sadzuka
authors.forename: T
authors.initials: T
authors.lastname: Sugiyama
authors.forename: T
authors.initials: T
authors.lastname: Sonobe
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000037:antagonists & inhibitors; D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000378:metabolism / Q000627:therapeutic use*; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000378:metabolism / Q000627:therapeutic use*; D001692:Biological Transport / Q000187:drug effects; D002110:Caffeine / Q000008:administration & dosage; D002121:Calcium Channel Blockers / Q000008:administration & dosage; D002286:Carcinoma, Ehrlich Tumor / Q000188:drug therapy* / Q000378:metabolism; D002392:Catechin / Q000008:administration & dosage / Q000031:analogs & derivatives; D004317:Doxorubicin / Q000008:administration & dosage / Q000378:metabolism; D018432:Drug Resistance, Multiple; D004354:Drug Screening Assays, Antitumor; D004357:Drug Synergism; D005419:Flavonoids / Q000008:administration & dosage; D005971:Glutamates / Q000008:administration & dosage; D007424:Intracellular Fluid / Q000378:metabolism; D007941:Leukemia P388 / Q000188:drug therapy* / Q000378:metabolism; D008297:Male; D051379:Mice; D009368:Neoplasm Transplantation; D008517:Phytotherapy; D013662:Tea / Q000737:chemistry / Q000627:therapeutic use*; D013805:Theobromine / Q000008:administration & dosage; D014700:Verapamil / Q000008:administration & dosage
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000972:Antineoplastic Agents, Phytogenic; D002121:Calcium Channel Blockers; D005419:Flavonoids; D005971:Glutamates; D013662:Tea; D002110:Caffeine; D004317:Doxorubicin; C026166:theanine; D002392:Catechin; C045651:epigallocatechin gallate; D014700:Verapamil; D013805:Theobromine