2.8.3. Nitric oxide radical scavenging assay

The nitric oxide radical scavenging (NOs) activity of the extracts was determined using the Griess reagent (1% sulfanilamide in 5% phosphoric acid (H₃PO₄) and 0.1% N‐(1‐naphthyl)ethylenediamine in distilled water in equal volumes) according to the procedure described by Huang and Tocmo (²⁰¹⁸). Briefly, sodium nitroprusside (Na₂[Fe(CN)₅NO]) in phosphate‐buffered saline (10 mM, pH = 7.3) was added to different concentrations of samples in a ratio of 1:1 and incubated for 30 min at room temperature. Next, 300 μl of incubated solution was mixed with 300 μl of Griess reagent and the absorbance was measured at 540 nm after 10 min incubation. The NOs activity was calculated using the following formula:

Where A _C and A _S are the absorbance values of the control and extract samples at 540 nm, respectively.