Ultrasensitive Time-Resolved Fluoroimmunoassay for Saikosaponin a in Chaihu (Bupleuri Radix)

PLoS One. 2016 Mar 11;11(3):e0151032. doi: 10.1371/journal.pone.0151032. eCollection 2016.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apiaceae / metabolism*
  • Drugs, Chinese Herbal / chemistry*
  • Fluoroimmunoassay / methods*
  • Oleanolic Acid / analogs & derivatives*
  • Oleanolic Acid / chemistry
  • Oleanolic Acid / metabolism
  • Reproducibility of Results
  • Saponins / chemistry
  • Saponins / metabolism*

Substances

  • Drugs, Chinese Herbal
  • Saponins
  • Oleanolic Acid
  • saikosaponin D

Grants and funding

The work was supported by the following: NSFC no. 81373905 and no. 30873387, http://www.nsfc.gov.cn/, ZC; NSFC no. 81373905 and no. 30873387, http://www.nsfc.gov.cn/; GDNSF no. 2014A030313321, http://pro.gdstc.gov.cn/egrantweb/; ZC. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.