Phenolic Content, Antibacterial and Antioxidant Potential of Several Edible Agaricomycetes Mushrooms Sold in Public Bazaar in Bolu, Turkey

Abstract

Edible mushrooms are important natural foods that have been used since ancient times due to their delicious taste, high nutritional value, and various biological activities. In this study, antibacterial (against 10 different human pathogens) and antioxidant potentials (free radical scavenging activity and total phenol-flavonoid content) of 13 different wild-growing and the most popular edible mushrooms (Lactarius salmonicolor, L. deliciosus, L. volemus, L. piperatus, Boletus edulis, Marasmius oreades, Agaricus campestris, Tricholoma terreum, Hydnum repandum, Coprinus comatus, Ramaria sp., Cantharellus cibarius, and Pleurotus ostreatus) sold in a public bazaar in Bolu-Turkey were evaluated. Strong antibacterial capacities were observed with all tested Lactarius species, as well as M. oreades, A. campestris, T. terreum, H. repandum, and Ramaria sp. Significant antibacterial potentials of T. terreum and C. comatus against Staphylococcus epidermidis, Serratia marcescens, and Proteus vulgaris were observed for the first time. H. repandum strongly inhibited all tested Gram-positive bacteria (Staphylococcus aureus, S. epidermidis, and Streptococcus pyogenes). It was remarkable to reveal strong growth inhibition of M. oreades against S. aureus (29.33 ± 1.11 mm) for the first time. The highest total phenolic content was revealed with L. delicious (193.42 ± 0.77 mg GAE/g dw and 198 ± 0.79 mg TAE/g dw), while L. salmonicolor had the highest total flavonoid content (358.33 ± 15.27 mg CE/g dw). B. edulis demonstrated the strongest antioxidant activity with the lowest IC50 value (4.48 ± 0.04 μg/mL). Moreover, L. deliciosus and M. oreades also had high antioxidant potential with the lowest IC50 values (4.76 ± 0.01 μg/mL and 4.77 ± 0.02 μg/mL, respectively). Total phenolic contents of tested mushrooms were highly correlated with their antioxidant capacities. L. delicious is the most well-known and the most delicious mushroom sold in Bolu's public bazaar. The obtained results for this mushroom were notable in terms of the greatest total phenol-flavonoid content and strong antioxidant capability. The antioxidant capacity and polyphenol content of L. deliciosus, M. oreades, H. repandum, A. campestris, and B. edulis, as well as their antibacterial activity, were quite outstanding, and our findings demonstrated the importance of these mushrooms as nutraceutical products.