Water soluble polysaccharidic and ethanolic fractions of wild edible mushrooms: chemical composition and bioactivity evaluation.

Mushrooms have become attractive as functional foods and as a source of physiologically beneficial bioactive compounds. The huge mushrooms reservoir of Northeast Portugal must be chemically and nutritionally characterized for the benefit of the local populations and for the genetic conservation of wild macrofungi. Herein, we describe and compare the chemical constituents (phenolic compounds, macronutrients, sugars, fatty acids, tocopherols and ascorbic acid) of four wild edible mushrooms widely appreciated in gastronomy: Armillaria mellea (Vahl) P. Kumm., Calocybe gambosa (Fr.) Donk, Clitocybe odora (Fr.) P. Kumm., Coprinus comatus (O.F. Müll.) Pers. Furthermore, the antioxidant and antitumour potential of their water soluble polysaccharidic and ethanolic fractions was studied by in vitro assays: radical scavenging activity, reducing power and lipid peroxidation inhibition for antioxidant activity, and sulforhodamine B assay for cell growth inhibition C. comatus revealed the highest concentrations of sugars (43.23/100 g dry weight), PUFA (77.46%), phenolic compounds (45.02 mg/kg), tocopherols (301.03 μg/100 g) and, among all of the fractions tested, its ethanolic fraction showed the highest antioxidant activity (EC50 < 2.6 mg/mL). C. odora revealed one of the highest ascorbic acid (172.65 mg/100 g) contents and its water soluble polysaccharidic fraction showed the best antioxidant properties (EC50 < 3.6 mg/mL) among the polysaccharidic fractions. The studied samples did not cause alterations in the cell growth of four human tumour cell lines (lung, breast, gastric and colon cancer). Therefore, despite the absence of antitumour potential, the studied mushroom species could potentially be used in well-balanced diets, as a source of antioxidant compounds