Development of a sensitive indirect competitive enzyme-linked immunosorbent assay for high-throughput detection and risk assessment of aflatoxin B1 in animal-derived medicines

Abstract

Animal-derived medicine is an important part of traditional Chinese medicine (TCM). Studies have shown that many animal-derived medicinal products are susceptible to contaminate of aflatoxins, nevertheless, the rapid detection for animal-derived medicine is prone to be ignored. Here we developed a sensitive indirect competitive enzyme-linked immunosorbent assay (icELISA) for rapid screening of aflatoxin B₁ (AFB₁) in ground beetle, cockroach, silkworm and earthworm. The sensitivity of the icELISA method was significantly enhanced. The IC₅₀ for the four animal-derived medicinal samples ranged from 0.092 to 0.135 ng mL^-1; the limit of detection (LOD) was 0.008-0.020 ng mL^-1. To obtain high accuracy, the extraction solution and time were evaluated. By using this method, a total of 138 samples were investigated, and the detection rates of AFB₁ in ground beetle and earthworm samples were 26.6% and 16.7%, respectively. The result was validated by liquid chromatography combined with tandem mass spectrometry, and an excellent correlation was observed between the two datasets, with a R² value of 0.999. Our results indicate that the proposed method can be used for the rapid detection of AFB₁ in animal-derived medicine. Furthermore, the quantitative risk assessment was conducted for ground beetle and earthworm based on the results, demonstrating that the intake of AFB₁ in ground beetle had a slight threat to the risk of cancer.

Keywords: Aflatoxin B(1); Animal-derived medicine; ELISA; Risk assessment; Screening method.