Cat enzyme solution

CAT levels were evaluated using the method described previously [6 (link)]. A CAT enzyme solution (1000 units/mL, Sigma-Aldrich, St. Louis, MO, USA) was used as a standard solution. The supernatant was mixed with sulfuric acid (RCI Labscan, Bangkok, Thailand), 30% hydrogen peroxide (Merck, Darmstadt, Germany) and 50 mM potassium phosphate buffer, pH 7.0 (KH₂PO₄, Ajax Finechem, Auckland, New Zealand). The mixture was vortexed and incubated in the dark at room temperature for 10 min. The mixture was gently mixed with potassium permanganate solution, pH 7.0 (Ajax Finechem, Auckland, New Zealand). The OD was read at 540 nm.

1000 units/mL of CAT enzyme solution (Sigma-Aldrich, MO, USA) was prepared as a standard compound. The supernatant was added to the solutions such as 50 mM potassium phosphate buffer, pH 7.0 (Ajax Finechem, Auckland, New Zealand), 30% hydrogen peroxide (Merck, Darmstadt, Germany), and sulfuric acid (RCI Labscan, Bangkok, Thailand). The reaction compound was incubated in the dark condition for 10 min before reacted with potassium permanganate solution (pH 7.0, Ajax Finechem, Auckland, New Zealand). The concentration of CAT was detected by evaluating the absorbance at 540 nm, and each sample was performed in triplicate.