2.7.1. DPPH radical scavenging activity assay

This study aimed to evaluate the capacity of the LsCrude and its fractions to attenuate free radicals. A consistent example of a free radical molecule is DPPH. When an antioxidant is present, it can donate electrons to DPPH, causing the usual purple color of the molecule to fade; this transformation in absorbance is quantified at a wavelength of 517 nm. The antioxidant activity of the plant extracts was assessed by utilizing the DPPH stable free radical scavenging effect [42,43]. First, 1 mL of a methanol solution containing 0.1 mM DPPH was added to 3 mL of each diluted extract (1 mg/mL) or ascorbic acid (1–100 μg/mL), with the latter used as a standard. The mixtures were incubated in the dark at room temperature for 30 min, and the absorbance at 517 nm was subsequently assessed in comparison to a control sample. The proportion of each extract's radical scavenging capacity was calculated using Equation (1):

where Ao is the absorbance of the blank, and As is the absorbance of the sample. The IC₅₀ values were calculated using linear regression analysis and used to indicate the antioxidant capacity.