Co-contamination of aflatoxin B₁and fumonisin B₁in food and human dietary exposure in three areas of China

Abstract

Aflatoxins and fumonisins are ubiquitous foodborne toxicants and the co-occurrence of these mycotoxins in human foods represents a significant public health concern, which has been strongly associated with human aflatoxicosis, neural tube defects, as well as many types of primary cancers. In this study the co-contamination of aflatoxin B(1) (AFB(1)) and fumonisin B(1) (FB(1)) in food and human dietary exposure was investigated in residents of three different areas of China. A total of 209 food samples were measured for AFB(1) and FB(1). The median AFB(1) levels were 13.5, 2.3 and 1.3 µg kg(-1) and the median FB(1) levels were 2.6, 0.4 and 0.3 mg kg(-1) in corn samples collected from Huaian (a high-risk area for oesophageal cancer), Fusui (a high-risk area for liver cancer) and Huantai (a low-risk area for both oesophageal and liver cancers), respectively. The median level of AFB(1) in plant oil of Fusui was the highest (52.3 µg kg(-1)) among all food samples analysed. Co-contamination of these two mycotoxins was found in corn, rice and wheat flour. Based on measured food consumption data, the averaged daily dietary intake of AFB(1) was 0.397 µg (range = 0.269-1.218 µg) in residents of Huantai, 1.723 µg (0.224-49.772 µg) in Huaian, and 2.685 µg (1.006-14.534 µg) in Fusui. The averaged FB(1) daily dietary intake was 92.4 µg (range = 55.0-362.1 µg) for residents of Huantai, 460.0 µg (83.2-2894.5 µg) in Huaian, and 138.6 µg (30.0-10,541.6 µg) in Fusui. These data suggest that the co-exposure to AFB(1) and FB(1) in residents of rural China may contribute to the aetiology of human chronic diseases in high-risk areas.

Genome-scale mutational signatures of aflatoxin in cells, mice, and human tumors

“…Conversely, only three of 268 HCCs from Japan, a region of low exposure, had AFB1sig. (6) Many of the HCCs with strong evidence of aflatoxin exposure also bore the TP53 R249S mutation, which sometimes indicates aflatoxin exposure in HCCs (Hollstein et al 1991;Montesano et al 1997;Sun et al 2011). The Qidong HCCs were selected based on the presence of this mutation, while six of the 11 tumors identified in Schulze et al (2015) had this mutation, as did four of the 12 from Sung et al (2012) (Supplemental Table S10).…”

“…The HCCs from Qidong were also selected for somatic TP53 R249S mutations, which is considered indicative of AFB1 exposure (Hollstein et al 1991;Montesano et al 1997;Sun et al 2011). The Qidong HCCs had high proportions of G > T mutations and transcription-strand bias skewed toward highly expressed genes, consistent with aflatoxin exposure (Supplemental Figs.…”

“…Conversely, a computationally extracted signature of aflatoxin exposure in HCCs, termed COSMIC Signature 24, has been described based on computational analysis of somatic mutations from the whole-exome sequencing (WES) of 11 tumors for which aflatoxin exposure was inferred from African or Asian origins or "race" and, in some HCCs, the presence of the TP53 R249S mutation, which occurs in roughly half of aflatoxin-exposed HCCs (Hollstein et al 1991;Montesano et al 1997;Ming et al 2002;Sun et al 2011;Schulze et al 2015). In addition, while the current paper was in review, a publication on HCCs from Qidong County, a region of known aflatoxin exposure, extracted a signature similar to COSMIC Signature 24 from HCC somatic mutations (Zhang et al 2017).…”

Assessment of Genotoxic and Cytogenetic Effects of Aflatoxin B1 in Mouse Bone Marrow Cells

“…Continued exposure to AFB1 results in stunted growth, mutagenicity, genotoxicity, and immunosuppression. It also caused an increasing hepatocellular carcinoma (HCC) incidence in humans and animals (Theumer et al, 2010;Abbes et al, 2010;Sun et al, 2011). Aflatoxin B1 works synergistically with some human health factors such as hepatitis B virus infection, nutritional status, sex, age and the amount of AFs exposure to initiate the development of cancer (Qureshi et al, 2014;Wild and Montesano, 2009).…”

Management of mycotoxins in Australian maize

“…Fumonisins have been found in high concentrations in maize grown in the high rainfall areas of Zambia (Kankolongo, Hell & Nawa 2009), Spain (Herrera et al 2010), China (Sun et al 2011), Italy (Mazzoni et al 2011). A combination of rainfall and high relative humidity on the first two days of silking have been strongly correlated to F. verticillioides infection, leading to a potentially higher fumonisin contamination (Martínez et al 2010) of the ear at harvest.…”