Progress in Immunoassays of Toxic Alkaloids in Plant-Derived Medicines: A Review

Abstract

Plants are the cradle of the traditional medicine system, assuaging human or animal diseases, and promoting health for thousands of years. However, many plant-derived medicines contain toxic alkaloids of varying degrees of toxicity that pose a direct or indirect threat to human and animal health through accidental ingestion, misuse of plant materials, or through the food chain. Thus, rapid, easy, and sensitive methods are needed to effectively screen these toxic alkaloids to guarantee the safety of plant-derived medicines. Antibodies, due to their inherent specificity and high affinity, have been used as a variety of analytical tools and techniques. This review describes the antigen synthesis and antibody preparation of the common toxic alkaloids in plant-derived medicines and discusses the advances of antibody-based immunoassays in the screening and detection of toxic alkaloids in plants or other related matrices. Finally, the limitations and prospects of immunoassays for toxic alkaloids are discussed.

Keywords: antibody; hapten design; immunoassay; plant-derived medicine; toxic alkaloid.

Figure 1

Development and scientific articles of immunoassays for plant-derived toxic alkaloids. The numbers in white represent the number of articles per decade. RIA: radioimmunoassay; ELISA: enzyme-linked immunosorbent assay; ICA: immune-chromatography assay; FIA: fluoroimmunoassay.

Figure 2

Common methods for conjugating hapten to the protein of toxic alkaloids. (A) Diazo method; (B) carbodiimide method; (C) glutaric dialdehyde method; (D) mixed anhydride method; (E) active ester method.

Figure 3

Application and schematic diagram of four types of immunoassays in the detection of plant-derived toxic alkaloids. RIA: radioimmunoassay; ELISA: enzyme-linked immunosorbent assay; ICA: immuno-chromatography assay; FIA: fluoroimmunoassay; Ex: excitation; Em: emission; T: test line; C: control line.