An in vitro model using the IPEC-J2 cell line for efficacy and drug interaction testing of mycotoxin detoxifying agents.

An in vitro model simulating the intestinal barrier for efficacy and drug interaction testing of mycotoxin detoxifying agents was developed using Transwell® cell culture inserts. Intestinal porcine epithelial cells derived from the jejunum of piglets were exposed to DON and a mycotoxin binder (efficacy testing) or exposed to tylosin and a mycotoxin binder (drug interaction testing). Active carbon and bentonite were used in the efficacy and drug interaction trials, respectively, to validate the developed model. The evaluated parameters were passage of DON and tylosin through the epithelial monolayer, the integrity of the monolayer by measurements of the trans-epithelial electrical resistance and the viability of the monolayer using the neutral red assay. In the efficacy model it was shown that active carbon effectively bound DON at both non-cytotoxic and cytotoxic concentrations of DON, respectively 0.5 and 1 μg/mL. Moreover, the negative effects of DON at cytotoxic concentrations on cellular viability and integrity were completely offset. A commercially available modified gluco-mannan binder was also tested and it was able to partly reduce the negative effects on these latter parameter. Moreover, it reduced the transepithelial passage of DON with 37% to 57% compared to active carbon, at both cytotoxic and non-cytotoxic concentrations of DON. In our drug interaction model, the interaction between tylosin and mycotoxin binders was investigated as some authors suggest binding of macrolide antibiotics to bentonite clays. Indeed, a bentonite clay showed decreased passage of tylosin through the epithelial monolayer, indicating binding of tylosin by bentonite. This indicates that the combined use of bentonite and tylosin in the feed could lead to therapy failure. The modified gluco-mannan binder did not alter the passage of tylosin significantly, indicating safe combined use.