Caco-2 cells (ATCC No. HTB37, American Type Culture Collection)
were maintained in complete growth medium containing 1%
(v/v) glutamine, 1% (v/v) nonessential amino acids, 1% (v/v) antibiotic
penicillin-streptomycin solution, 0.2% (v/v) antifungal
amphotericin B solution (fungizone) and Dulbecco's modified Eagle's
medium (DMEM), supplemented with 10% (v/v) heat inactivated
fetal bovine serum (FBS). Cells were maintained at 37 C in a
saturated humid atmosphere containing 95% air in a 5% CO2.