Figure 9. Grape extracts prevent CTA1 translocation to the cytosol.

HeLa cells were incubated with CT for 30 min at 4°C. Unbound toxin was removed, and the cells were warmed to 37°C. Grape pomace (A) or grape seed (B) extract was added to the cells 15, 30, or 60 min after warming to 37°C. Cell extracts generated after a total of 2 h at 37°C were separated into membrane and cytosolic fractions, and the cytosolic fractions were perfused over an SPR sensor coated with an anti-CTA1 antibody. The cytosolic fraction from unintoxicated cells was used as a negative control, and CTA standards were used as positive controls. All samples were perfused over the same SPR sensor; the data is presented in two panels for clarity. One of two representative experiments is shown.