Hydroxyl Radical (HO•) Scavenging Assay

The Fenton reaction is the most common chemical reaction that produces hydroxyl radicals. This experiment was carried out according to the instructions of the hydroxyl radical assay kit. Different concentrations of TSAT (0.01–1 mg/mL) were mixed with the reagents sequentially and left at room temperature for 20 min. Absorbance (550 nm) was measured, and VC was used as a positive control. The scavenging rate (%) was calculated as follows:

where A₀ is the absorbance of the negative control system without TSAT, A₁ is the absorbance of the reaction system containing TSAT, and A₂ is the absorbance of the reaction system containing double distilled water instead of H₂O₂. The IC₅₀ value was then calculated. All operations were performed in parallel three times.