Quantitative estimation of total phenols, total flavonoids, and antioxidant activity of methanolic extracts of Ephedra gerardiana Wall. ex Stapf across different habitats of cold desert biosphere reserve, trans Himalaya, India

Abstract

The present study evaluated phenolic compounds and antioxidant properties of methanolic extracts of aerial part and root of a high altitude threatened species, Ephedra gerardiana Wall. ex Stapf (Fam: Ephedraceae). E. gerardiana was collected from five distantly located populations in Cold Desert Biosphere Reserve. The concentration of total phenolic contents was recorded in range between 110±3.5 to 132±2.52 (aerial part) and 135±0.6 to161±0.49 (root) mg GAE g−1 of extracts and flavonoid contents was recorded between 66±1.47 to 87±0.84 (aerial part) and 108±1 to 137±0.48 (root) mg QE g−1. Total phenolic contents were significantly higher in E. gerardiana population growing on river bed habitat. One way analysis of variance (ANOVA) revealed significant variation among populations. All extracts exhibited strong antioxidant activity. The percent inhibition was found to increase with every unit increase in concentration. The DPPH and ABTS radical scavenging reached up to 82.15% and 97.55% at a concentration of 400 μg mL−1, respectively. Reducing power was ranged from 0.198±0.001 to 0.597±0.005 at concentrations ranging from 50 to 400 μg mL−1. Therefore, present study results revealed that E. gerardiana is a natural source of antioxidant.