Nutrient composition, antioxidant properties, and anti-proliferative activity of Lignosus rhinocerus Cooke sclerotium.

Lignosus rhinocerus (tiger milk mushroom) is an important medicinal mushroom used in Southeast Asia and China, and its sclerotium can be developed into functional food/nutraceuticals. The nutrient composition, antioxidant properties, and anti-proliferative activity of wild type and a cultivated strain of L. rhinocerus sclerotia were investigated. The sclerotial powder has high carbohydrate but low fat content. Interestingly, the cultivated strain contains higher amounts of protein and water-soluble substances than the wild type. Phenolic content of hot-water, cold-water, and methanol extracts of the sclerotial powders ranged from 19.32 to 29.42 mg gallic acid equivalents g⁻¹ extract, while the ferric reducing antioxidant power values ranged from 0.006 to 0.016 mmol min⁻¹ g⁻¹ extract. The DPPH• , ABTS•⁺ , and superoxide anion radical scavenging activities of the extracts ranged from 0.52 to 1.12, 0.05 to 0.20, and -0.98 to 11.23 mmol Trolox equivalents g⁻¹ extract, respectively. Both strains exhibited strong superoxide anion radical scavenging activity comparable to rutin. The cold-water extracts exhibited anti-proliferative activity against human breast carcinoma (MCF-7) cells, with IC₅₀ values of 206 µg mL⁻¹ and 90 µg mL⁻¹ for the wild type and cultivated strains, respectively. The cultivated L. rhinocerus sclerotium has the potential to be developed into functional food/nutraceuticals. © 2013 Society of Chemical Industry.