The edible mushroom Laetiporus sulphureus as potential source of natural antioxidants

Abstract

Hot water extract (LN), partially purified polysaccharides (LP) and hot alkali extracted polysaccharides (LNa) obtained from fruiting bodies of the wild basidiomycete Laetiporus sulphureus were examined for their antioxidant activities. LNa was the most active antioxidant, as shown by the median effective concentrations (EC₅₀ values) of 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity (0.5 ± 0.2 mg/ml), reducing power (4.0 ± 0.3 mg/ml) and ferrous ion-chelating ability (1.5 ± 0.1 mg/ml). LNa contained the highest level of α-glucan (17.3 ± 1.2 g/100 g dw), whereas LP contained mostly β-glucans (66.8 ± 1.3 g/100 g dw). The prevalent monosaccharide in all extracts was glucose. The EC₅₀ values of all three antioxidant activity assays were well-correlated with the α-glucan content. Strong and significant correlation was found between total phenolic compounds and DPPH scavenging ability and also reducing power. The three investigated extracts (at concentrations of 0.1–10 mg/ml) were not toxic to HTR-8/SVneo trophoblast cell line.

Keywords::

• Laetiporus sulphureus
• antioxidant activity
• β-glucan
• polysaccharide extracts
• polyphenols
• cytotoxicity

Acknowledgement

The authors wish to thank Dr Charles H. Graham (Queen's University, Kingston, Canada) who kindly provided the HTR-8/SVneo trophoblast cell line.

Declaration of interest : This investigation was financially supported by the Ministry of Science and Technological Development of the Republic of Serbia, projects III 46001, III 46010 and III 43004. The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.