A safety assessment of hot aqueous mycelium extracts from Trametes versicolor and Lepista nuda as a food supplement

Abstract

Trametes versicolor (L.) Lloyd and Lepista nuda (Bull.) Cooke, known as an edible and medicinal mushroom, draws attention as a source of functional food development. Investigation of these fungal species on blood cultures in terms of human health will supplement the literature. In this study, the biomass of T. versicolor and L. nuda were used to prepare hot aqueous mycelium extracts (HAMEs). HAMEs were evaluated for antioxidant activity and cytotoxicity on human blood cultures (HBCs) in vitro. HBCs were initially incubated with HAMEs in 0.01-2 g/L dose ranges for 1 and 2 days and then analyzed. Firstly, the antioxidant activity on blood serum was determined by using Rel Assay kits with TAC (total antioxidant capacity), TOS (total oxidant status), and OSI (oxidative stress index) values. Secondly, cytotoxicity on lymphocytes was determined using neutral red uptake (NRU) and lactate dehydrogenase (LDH) assays. Doses of 0.05 to 0.5 g/L of T. versicolor and L. nuda increased TAC levels and decreased TOS values. 0.01 and 1 g/L did not change the TOS values but increased it by 2 g/L. In the second case, the dose range 0.01-1 g/L did not offer cytotoxic data. However, 2 g/L caused a 2 % increase in LDH and a 7 % decrease in NRU. As a result, this study presented that any evident signs of toxicity did not accompany T. versicolor and L. nuda HAMEs applications at 0.01-1 g/L dose ranges and 1–2 days on HBCs. The lack of toxicity supports the potential usage of T. versicolor and L. nuda in specified doses as a food or dietary supplement.