In vitro antioxidant activity and phytochemical analysis of Teucrium pseudo-Scorodonia Desf. Collected from Algeria

Abstract

Teucrium pseudo-Scorodonia Desf., is one of many Mediterranean plants widely used in Algerian folk medicine for their medicinal properties. This study represents the first antioxidant investigation of Teucrium pseudo-Scorodonia with different analytical methods. Total phenolic, flavonoid, and condensed tannin contents were determined using spectrophotometric techniques. In vitro antioxidant and radical scavenging profiling was determined through total antioxidant capacity (TAC), DPPH radical-scavenging, ferric reducing antioxidant power (FRAP), and β-carotene bleaching assays. Leaf extracts exhibited high total phenolics (266.36 ± 0.14 mg GAE/g DW), flavonoids (161.23 ± 0.18 mg CE/g DW) and condensed tannins (5.00 ± 0.08 mg CE/g DW) contents. The greatest antioxidant activity was founding in the butanolic fraction of leaves (IC50.DPPH = 0.05 ± 0.00 mg/ml) followed by crude methanolic extract and ethyl acetate fraction. These values were to some extent high in comparison to the positive control (0.07 ± 0.01 mg/ml). The same tendency was observed with ferric reducing power. A strong correlation of IC50 values of antioxidant assays with total phenolics and total flavonoids content of T. pseudo-Scorodonia was exhibited in this study. Thin layer chromatographic (TLC) screening using DPPH radical, AlCl3 and FeCl3 as detection reagents led to the identification of potent antioxidant compounds: methylated flavonoids or hydroxyflavonols. These results indicate that flavonoids and phenolics can be the major contributors to the antioxidant activity observed for the T. pseudo-Scorodonia leaf extracts. Further study is necessary for isolation and characterization of the active antioxidants, which may serve as a potential source of natural antioxidants.