title: Ultrasensitive Time-Resolved Fluoroimmunoassay for Saikosaponin a in Chaihu (Bupleuri Radix).
abstract: The aim of this study is to establish a time-resolved fluoroimmunoassay (TRFIA) system for quantitative analysis of saikosaponin a (SSa) in the crude drug of Chaihu (Bupleuri Radix). A 96-well microplate coated with rabbit anti-mouse IgG was incubated with the methanol extracts of Chaihu samples and a mouse anti-SSa monoclonal antibody, and a Eu3+-labeled SSa-human serum albumin conjugate was used as the tracer. The established competitive TRFIA showed a good fourth order polynomial fitting from 0.01 to 10.0 μg/mL for standard SSa sample with a detection limit of 0.006 μg/mL. The intra- and inter-assay coefficients of variation of the assay were 7.3% and 8.9%, respectively, and the average SSa recovery was 119.2%. For samples of Chaihu extract, the results of this assay showed a good correlation with those by enzyme-linked immunosorbent assay established previously. This TRFIA system is ultrasensitive for detecting SSa with a wide detection range and a good stability and represents the first attempt of using TRFIA for quality evaluation of the crude drug of Chaihu.
authors.affiliation: School of Traditional Chinese Medicine, Southern Medical University, Guangzhou 510515, China.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Chao
authors.affiliation: School of Traditional Chinese Medicine, Southern Medical University, Guangzhou 510515, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Cui
authors.affiliation: School of Traditional Chinese Medicine, Southern Medical University, Guangzhou 510515, China.
authors.forename: Enwei
authors.initials: E
authors.lastname: Tian
authors.affiliation: School of Traditional Chinese Medicine, Southern Medical University, Guangzhou 510515, China.
authors.forename: Weiping
authors.initials: W
authors.lastname: Zeng
authors.affiliation: School of Traditional Chinese Medicine, Southern Medical University, Guangzhou 510515, China.
authors.forename: Xuan
authors.initials: X
authors.lastname: Cai
authors.affiliation: School of Traditional Chinese Medicine, Southern Medical University, Guangzhou 510515, China.
authors.forename: Xiaolei
authors.initials: X
authors.lastname: Li
authors.affiliation: Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Tanaka
authors.affiliation: Faculty of Pharmaceutical Sciences, Nagasaki International University, Sasebo 859-3298, Japan.
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Shoyama
authors.affiliation: School of Biotechnology, Southern Medical University, Guangzhou 510515, China.
authors.forename: Yingsong
authors.initials: Y
authors.lastname: Wu
mesh_terms: D019661:Apiaceae / Q000378:metabolism*; D004365:Drugs, Chinese Herbal / Q000737:chemistry*; D015200:Fluoroimmunoassay / Q000379:methods*; D009828:Oleanolic Acid / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism; D015203:Reproducibility of Results; D012503:Saponins / Q000737:chemistry / Q000378:metabolism*
chemical_list: D004365:Drugs, Chinese Herbal; D012503:Saponins; D009828:Oleanolic Acid; C025759:saikosaponin D