Homogenates were centrifuged (Rotor SA-600, Sorvall, RC 5C Plus, Kendro Laboratory Products, Newtown, CT) at 29,000 x g for 15 min at 4 °C. Sample aliquots of 25 μL were taken from the clear supernatant and then diluted with 2525 μLnanopure water, followed by 150 μL of 0.25 N Folin-Ciocalteu and incubated for 3 min at room temperature.