title: Topoisomerase I inhibition and cytotoxicity of licochalcones A and E from Glycyrrhiza inflata.
abstract: Licochalcones A (1) and E (2), retrochalcones or reversely constructed chalcones, isolated from the roots of Glycyrrhiza inflata, were evaluated for their cytotoxicities against four different human tumor cell lines; A549 (lung), SK-OV-3 (ovarian), SK-MEL-2 (melanoma) and HCT-15 (colon), using the sulforhodamine B (SRB) assay. The effects of these compounds toward the DNA topoisomerase I (topo I) inhibitory activity were also measured using the supercoiled DNA unwinding assay. All compounds showed moderate cytotoxicities against the four different human tumor cell lines and inhibited the topo I activity in dose-dependent manners. The inhibition of topo I by licochalcones A (1) and E (2) may explain the cytotoxicities of these compounds against the human tumor cell lines.
authors.affiliation: College of Pharmacy and Research Institute of Drug Development, Chonnam National University, 300 Yongbong-Dong, Buk-Gu, Gwangju 500-757, Korea.
authors.forename: Goo
authors.initials: G
authors.lastname: Yoon
authors.forename: Bok Yun
authors.initials: BY
authors.lastname: Kang
authors.forename: Seung Hoon
authors.initials: SH
authors.lastname: Cheon
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D002460:Cell Line; D047188:Chalcones / Q000494:pharmacology*; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D006035:Glycyrrhiza / Q000737:chemistry*; D006801:Humans; D013329:Structure-Activity Relationship; D059004:Topoisomerase I Inhibitors
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D047188:Chalcones; D004791:Enzyme Inhibitors; D059004:Topoisomerase I Inhibitors; C520147:licochalcone E; C070840:licochalcone A