title: Wogonin potentiates the antitumor action of etoposide and ameliorates its adverse effects.
abstract: Wogonin, a flavone in the roots of Scutellaria baicalensis, reduced etoposide-induced apoptotic cell death in normal cells, such as bone marrow cells and thymocytes. On the other hand, wogonin potentiated the proapoptotic or cytotoxic action of etoposide in tumor cells, such as Jurkat, HL-60, A549, and NCI-H226. These contradictory actions of wogonin on apoptosis are distinguished by normal or cancer cell types. Wogonin had no effect on apoptosis induced by other anticancer agents in the tumor cells. Thus, the potentiation effect of wogonin was observed only in etoposide-induced apoptosis in tumor cells. In a functional assay for P-glycoprotein (P-gp), wogonin suppressed excretion of calcein, a substrate for P-gp, in these tumor cells. Moreover, wogonin decreased the excretion of radiolabeled etoposide and accordingly increased intracellular content of this agent in the cells. P-gp inhibitors showed a similar potentiation effect on etoposide-induced apoptosis in these tumor cells. Thus, wogonin is likely to potentiate the anticancer action of etoposide due to P-gp inhibition and accumulation of this agent. These findings suggest that wogonin may be a useful chemotherapeutic adjuvant to potentiate the pharmacological action of etoposide and ameliorate its adverse effects.
authors.affiliation: Laboratory of Pharmacology, Faculty of Pharmaceutical Sciences, Kobe Gakuin University, 1-1-3, Minatojima, Chuo-ku, Kobe 650-8586, Japan.
authors.forename: Riyo
authors.initials: R
authors.lastname: Enomoto
authors.forename: Chika
authors.initials: C
authors.lastname: Koshiba
authors.forename: Chie
authors.initials: C
authors.lastname: Suzuki
authors.forename: Eibai
authors.initials: E
authors.lastname: Lee
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000037:antagonists & inhibitors; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology* / Q000633:toxicity; D017209:Apoptosis / Q000187:drug effects; D001854:Bone Marrow Cells / Q000166:cytology / Q000187:drug effects; D045744:Cell Line, Tumor; D019008:Drug Resistance, Neoplasm; D004357:Drug Synergism; D004365:Drugs, Chinese Herbal / Q000494:pharmacology; D005047:Etoposide / Q000494:pharmacology* / Q000633:toxicity; D044950:Flavanones / Q000494:pharmacology*; D006801:Humans; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D051381:Rats; D017207:Rats, Sprague-Dawley; D031364:Scutellaria baicalensis; D013950:Thymus Gland / Q000166:cytology
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000970:Antineoplastic Agents; D004365:Drugs, Chinese Herbal; D044950:Flavanones; D005047:Etoposide; C085514:wogonin