Abstract

The antioxidant activities of the methanolic extracts of Ephedra laristanica growing in Iran were evaluated using ferric reducing antioxidant power (FRAP) and 2, 2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assays. FRAP values 2.1 mmol eq quercetin/g extracts, and IC₅₀ values in the DPPH assay 4.6 mg/mL. This plant showed the high antioxidant activities. FRAP and DPPH assay results showed good correlations with the total phenolic contents of the plants, measured by the Folin-Ciocalteau assay (r² = 0.926 and 0.913, respectively, p < 0.0001). The antimicrobial capacity was screened against Gram positive and Gram negative bacteria, and fungi. The extract inhibited the growth of Gram negative bacteria, being Escherichia coli the most susceptible one with MIC of 32 μg/mL for the extract. The results obtained indicate that E. laristanica may become important in the obtainment of a noticeable source of compounds with health protective potential and antimicrobial activity.

Key words: Antioxidant(s), ferric reducing antioxidant power (FRAP), 2, 2-diphenyl-1-picrylhydrazyl (DPPH), total phenol, antimicrobial.