Phenolic Content and Antioxidant Activity of Scrophularia scorodonia Ethanolic Extract

Abstract

Scrophularia scorodonia, a herbaceous species belonging to the Scrophulariaceae family, traditionally used in folk medicine and known for its rich phytochemical composition. The present study aimed to investigate the antioxidant properties of S .scorodonia plant, focusing on the extraction and quantification of its phenolic and flavonoid compounds, as well as the evaluation of its antioxidant activity using in vitro assays. A hydroalcoholic extract (70% ethanol) was obtained by maceration of the aerial parts of the plant ,and phytochemical screening was performed to identify major classes of secondary metabolites. Total phenolic content (TPC) and total flavonoid content (TFC) were determined using the Folin–Ciocalteu and aluminum chloride colorimetric methods, respectively. Antioxidant activity was assessed through three complementary assays: DPPH radical scavenging, ferric reducing antioxidant power (FRAP), and total antioxidant capacity (TAC). The extraction yield was 12.44%. Phytochemical screening revealed the presence of polyphenols, flavonoids, and quinones. The TPC was found to be 60 ± 0.12 mg GAE/g extract, while TFC was 26 ± 0.054 μg QE/mg extract. The DPPH assay showed a dose-dependent radical scavenging activity with an IC₅₀ of 56.21 μg/mL, compared to 6.97 μg/mL for BHA. The FRAP assay indicated a maximum reducing power of 13.36 μg QE/mL with an EC₅₀ value of 296.38 ± 47.55 μg/mL, and the TAC assay demonstrated 44.73% and 37.65% of the antioxidant capacity of ascorbic acid and quercetin, respectively. These results highlight the significant antioxidant potential of S. scorodonia, supporting its traditional use and encouraging future investigations.