Antioxidant Activity, Polyphenols Content and Antimicrobial Activity of Several Native Pteridophytes of Romania

Abstract

The aim of this paper was to test the antioxidant activity, polyphenols content and antimicrobial activity of crude extracts obtained from leaves of pteridophyte species commonly found in Romania. The ORAC (Oxygen Radical Absorbance Capacity) of the investigated ferns varied between 421.90 ?mol TE (Trolox equivalents/g FW (fresh weight) in Dryopteris filix-mas and 128.18 ?mol TE/g FW in D. affinis. Methanolic extracts obtained from leaves of ferns have similar antioxidant activity to that of some medicinal plants. Polyphenols content in the leaves of ferns varies between 2340 mg Gallic acid equivalents (GAE)/100 g FW in D. filix-mas and 887 mg GAE/100 g FW in D. affinis. The correlation coefficient between ORAC and the total polyphenol content was R=0.985. This correlation suggests that phenolic compounds are major contributors to the antioxidant activity. The methanolic extract obtained from ferns inhibits the growth of Gram negative Escherichia coli ATCC 25922, Pseudomonas aeruginosa NBJMCC1390, Salmonella abony and Gram positive Staphyllococcus aureus ATCC 25093 and Enterococcus faecalis. The highest antimicrobial activity was determined for the Dryopteris extract. The antimicrobial activity of methanolic extracts obtained from leaves of D. filix-mas and D. affinis is better than the A. filix-femina in the case of Brevibacterium flavum ATCC 14067, Sarcina sp., Bacillus cereus ATCC 1390, Saccharomyces cerevisiae and Aspergillus niger. The tested ferns could be used as cosmetic ingredients, as preservatives in food or in antimicrobial therapy.