E plant lectins at concentrations ranging from 1 to 500 /ml. Triplicate wells were used for each treatment. The cells were incubated with the various compounds for 24 h at 37 in a humidified 5 CO2 atmosphere. To each well, 20 of MTT (0.5 mg/ml final concentration) was added and the plates were incubated at 37 for 4 h to allow MTT to form formazan crystals by reacting with metabolically activ