Antioxidant properties of extracts of wild medicinal mushroom species from Croatia.

Antioxidant activity and total phenol (TP) content of methanol and water extracts of three wild Croatian mushroom species Auricularia auricula-judae (Bull.) Quél., Sarcoscypha austriaca (Sacc.) Boud., and Strobilurus esculentus (Wulfen) Singer were determined and compared with the values obtained for extracts of four cultivated mushrooms Agaricus bisporus (J.E. Lange) Imbach (brown and white strains), Pleurotus ostreatus (Jacq.) P. Kumm., and Lentinus edodes (Berk.) Singer. Spectrophotometric determination of the TP content was performed using the Folin-Ciocalteu method, while antioxidant activity was measured in a reaction with 1,1-diphenyl-2-picrylhydrazyl radical (DPPH assay) and ferric-tripyridyltriazine (Fe3+-TPTZ) complex (FRAP assay). On the average, 5.8-fold higher TP content was observed for water in comparison to methanol extracts of all analyzed mushrooms. Consequently, antioxidant activity was also higher for water extracts, which is evident from the obtained higher values in the FRAP assay and lower EC50 values in the DPPH assay. Among the three tested wild species, the water extract of S. esculentus exhibited the highest concentration of TP, 8.12 mg/g gallic acid equivalents (GAE), the highest reducing power, 19.42 mmol Fe2+/kg, and the best radical scavenging properties, EC50= 13.5 mg/mL.