A comparative study of the antibacterial, antifungal and antioxidant activity and total content of phenolic compounds of cell cultures and wild plants of three endemic species of Ephedra

Abstract

Investigations were carried out to determine antimicrobial and antioxidant properties and total phenol content of three wild species of Ephedra compared with their respective callus cultures. Callus induction was performed in a standard Murashige and Skoog (MS) medium with the following hormonal ranges (mg/L) for every species NAA:1.5, Kin:1 for Ephedra strobiliacea, NAA:2, Kin:1 for Ephedra procera and NAA:2, Kin:0.5 for Ephedra pachyclada. These ranges of PGPR (Plant Growth Promote Regulators) were chosen based on callus induction rates, RGR (Relative Growth Rate) and their fresh weights. An antimicrobial test against five Gram negative and two Gram positive bacteria and two fungi was performed using the disc diffusion method. All methanolic extracts showed antimicrobial activity, but the antimicrobial activity of the callus cultures was lower than those of the wild plants. E. strobilacea showed the highest antimicrobial activity, and all methanolic extracts of the wild plants and callus cultures unexpectedly showed the highest antimicrobial activity against Pseudomonas aeruginosa. A FRAP (Ferric Reducing Antioxidant Power) test was conducted to evaluate extracts for antioxidant activity. E. strobilacea with 1.61 ± 0.08 mmol eq quercetin/g extract and 0.278 ± 0.02 mmol eq quercetin/g extract for the wild plant and callus, respectively, showed the highest results. The total phenol content of extracts was measured by a Folin Ciocalteau test. All the chosen species displayed phenol contents but E. strobilacea had the highest amount (504.9 ± 41.51 μmol eq catechin/g extracts and 114.61 ± 15.13 μmol eq catechin/g extracts for the wild plants and callus, respectively). © 2010 by the authors.