Abstract #T166

Section: Food Safety
Session: Food Safety
Format: Poster
Day/Time: Tuesday 7:30 AM–9:30 AM
Location: Gatlin Ballroom
# T166
Interaction of aflatoxin M1, ochratoxin A, zearalenone, and α-zearalenol combinations on Caco-2 cells.
Yanan Gao1,2, Nan Zheng1,2, Songli Li1,2, Yangdong Zhang1,2, Jiaqi Wang*1,2, 1Ministry of Agriculture Laboratory of Quality & Safety Risk Assessment for Dairy Products (Beijing), Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China, 2State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China.

It is common to find the co-occurrence of aflatoxin B1 (AFB1), ochratoxin A (OTA), zearalenone (ZEA) in feed. These mycotoxins can be metabolized or transferred to raw milk in the forms of Aflatoxin M1 (AFM1), ochratoxin A (OTA), ZEA, and α-zearalenol (α-ZOL), which are stable in processing of dairy products. The aim of the present study is to investigate the cytotoxicity of combined mycotoxins of AFM1, OTA, ZEA, and α-ZOL on the human colon adenocarcinoma cell lines (Caco-2) by using the tetrazolium salt (MTT) assay and the isobologram analysis. Statistical analysis of data was carried out using SAS9.2 statistical software package. Our results demonstrated the significant cytotoxic effects (P < 0.05) of the 2-toxin, 3-toxin and 4-toxin combination on Caco-2 cells in a time- and concentration-dependent manner. The results from MTT assay demonstrated that AFM1 had the similar cytotoxicity as OTA (IC50 = 4.10 μM) upon exposure for 72 h, which was much higher than that of ZEA and α-ZOL. The cytotoxic effect of the all the mycotoxin combinations increased in the following order: OTA+α-ZOL < ZEA+α-ZOL < OTA+ZEA < AFM1+ZEA < AFM1+α-ZOL < AFM1+OTA < OTA+ZEA+α-ZOL < AFM1+ZEA+OTA < AFM1+ZEA+α-ZOL < AFM1+OTA+α-ZOL < AFM1+ZEA+OTA+α-ZOL. Isobologram analysis was further indicated that the existence of AFM1 brought additive effect at IC50 and even synergism at IC25. The synergistic effect of the 4-toxin group is the highest of all mytotoxin combinations investigated (Combination Index = 0.17 ± 0.05 at IC25). Other cell lines will be further studied in the future to obtain an appropriate health risk assessment of milk.

Key Words: aflatoxin M1, cytotoxicity, interaction