Cells after Exposure to T. esculentum Extracts. Release of NO after cell exposure to T. esculentum extracts was detected using a microplate reader (Multiscan, Finland) at 540 nm after introduction of Griess reagent (Sigma, Germany) into supernatants after 24-hour incubation. Results were expressed as percent difference between nitric oxide release of test from control. Nitric oxide is proportional to the amount of nitrate accumulating in supernatants as shown by the change of colour at 540 nm.