title: Reversal of P-glycoprotein-dependent resistance to vinblastine by newly synthesized bisbenzylisoquinoline alkaloids in mouse leukemia P388 cells.
abstract: We examined the ability of partially synthesized new compounds from fangchinoline and tetrandrine to reverse P-glycoprotein (P-gp)-dependent multidrug resistance (MDR) in vitro and in vivo. All compound enhanced the in vitro cyctotoxic effect of vinblastin (VBL) at 0.1 microM as potent as 10 microM verapamil against the resistant cell line P388/ADR. The combination effect tended to be strong by substitution of bulky group, resulting 5,14-dibromotetrandrine (compound #9) showed the strongest effect. Compound #9 increased intracellular VBL accumulation in P388/ADR cells, much stronger than verapamil, as well as cytotoxic combined effect. This mechanism seems to inhibit the function of P-gp, but not the expression of P-gp. In combination with VBL, this compound also synergistically prolonged the life-span of P388/ADR-bearing mice. Bisbenzylisoquinoline alkaloids and their derivatives are possible to be good candidates as modifier of MDR in cancer chemotherapy.
authors.affiliation: Department of Natural Organic Chemistry, School of Pharmacy, West China University of Medical Sciences; Chengdu 610041, China.
authors.forename: Feng-Peng
authors.initials: FP
authors.lastname: Wang
authors.forename: Li
authors.initials: L
authors.lastname: Wang
authors.forename: Jin-Song
authors.initials: JS
authors.lastname: Yang
authors.forename: Masaaki
authors.initials: M
authors.lastname: Nomura
authors.forename: Ken-Ichi
authors.initials: K
authors.lastname: Miyamoto
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000037:antagonists & inhibitors*; D000470:Alkaloids / Q000494:pharmacology*; D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D044182:Benzylisoquinolines / Q000494:pharmacology*; D045744:Cell Line, Tumor; D019008:Drug Resistance, Neoplasm; D005260:Female; D007941:Leukemia P388 / Q000473:pathology*; D051379:Mice; D014747:Vinblastine / Q000494:pharmacology*
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000470:Alkaloids; D000972:Antineoplastic Agents, Phytogenic; D044182:Benzylisoquinolines; D014747:Vinblastine