In vitro antioxidant properties and antimicrobial activity of the ethanolic extract of Senecio nutans Sch. Beep. (Asteraceae)

Abstract

Context: Senecio nutans Sch. Beep. is used by the Andean population of Ayacucho-Peru as traditional medicine for various health problems. Aims: To evaluate the antioxidant and antimicrobial activity of the ethanolic extract of leaves of S. nutans against the enteropathogen Escherichia coli and the filamentous fungus Aspergillus niger. Methods: The antioxidant capacity of the ethanolic extract was evaluated by ABTS, DPPH, and FRAP assays; the antimicrobial activity was evaluated by the agar diffusion method, and determining the minimum inhibitory concentration (MIC), minimum bactericidal (MBC), and fungicidal concentration (MFC). Results: Polyphenols, terpenes, and tannins were identified; the total polyphenolic content was 67.91 ± 0.29 mg GAE/g. The ethanolic extract at 20 mg/mL showed moderate antibacterial activity (79.14 ± 0.02% inhibition, MIC and MBC >400 μg/mL on E. coli), and antifungal (88.90 ± 0.17% inhibition, MIC and MCF >400 μg/mL on A. niger); radical scavenging capacity (ABTS 10.31 ± 0.09 mM TE/g; DPPH 8.28 ± 0.07 IC50 µg/mL) and iron reducing power (FRAP 17.72 ± 0.11 mM TE/g). S. nutans turned out to be a potential antimicrobial and antioxidant species associated with the presence of its bioactive components, for which further investigation is warranted. Conclusions: The ethanolic extract of leaves S. nutans showed moderate activity against pathogenic bacteria (E. coli) and filamentous fungus (A. niger), as well as antioxidant activity in three in vitro methods.

Keywords

• antimicrobial activity
• chachacoma
• in vitro antioxidant activity
• phenolic compounds
• senecio nutans