title: Inhibition of the human ether-a-go-go-related gene (HERG) K+ channels by Lindera erythrocarpa.
abstract: Lindera erythrocarpa Makino (Lauraceae) is used as a traditional medicine for analgesic, antidote, and antibacterial purposes and shows anti-tumor activity. We studied the effects of Lindera erythrocarpa on the human ether-a-go-go-related gene (HERG) channel, which appears of importance in favoring cancer progression in vivo and determining cardiac action potential duration. Application of MeOH extract of Lindera erythrocarpa showed a dose-dependent decrease in the amplitudes of the outward currents measured at the end of the pulse (I(HERG)) and the tail currents of HERG (I(tail)). When the BuOH fraction and H(2)O fraction of Lindera erythrocarpa were added to the perfusate, both I(HERG) and I(tail) were suppressed, while the hexane fraction, CHCl(3) fraction, and EtOAc fraction did not inhibit either I(HERG) or I(tail). The potential required for half-maximal activation caused by EtOAc fraction, BuOH fraction, and H(2)O fraction shifted significantly. The BuOH fraction and H(2)O fraction (100 microg/mL) decreased g(max) by 59.6% and 52.9%, respectively. The H(2)O fraction- and BuOH fraction-induced blockades of I(tail) progressively decreased with increasing depolarization, showing the voltage-dependent block. Our findings suggest that Lindera erythrocarpa, a traditional medicine, blocks HERG channel, which could contribute to its anticancer and cardiac arrhythmogenic effect.
authors: Department of Physiology, Institute of Bioscience and Biotechnology, Kangwon National University College of Medicine, Chuncheon, Korea.
authors: Hee-Kyung
authors: HK
authors: Hong
authors: Weon-Jong
authors: WJ
authors: Yoon
authors: Young Ho
authors: YH
authors: Kim
authors: Eun-Sook
authors: ES
authors: Yoo
authors: Su-Hyun
authors: SH
authors: Jo
mesh_terms: D000818:Animals; D000440:Butanols / Q000737:chemistry / Q000378:metabolism; D051638:Ether-A-Go-Go Potassium Channels / Q000037:antagonists & inhibitors* / Q000378:metabolism; D005260:Female; D006801:Humans; D027443:Lindera / Q000737:chemistry*; D009865:Oocytes / Q000166:cytology / Q000502:physiology; D018408:Patch-Clamp Techniques; D010936:Plant Extracts / Q000378:metabolism*; D026902:Potassium Channel Blockers / Q000378:metabolism*; D014982:Xenopus laevis
chemical_list: D000440:Butanols; D051638:Ether-A-Go-Go Potassium Channels; D010936:Plant Extracts; D026902:Potassium Channel Blockers