Exploring growth-inhibitory and immuno-stimulatory activity in British Columbia wild mushrooms and lichens.

Four mushroom and two lichen species were collected from selected forests in north-central British Columbia and screened for anti-proliferative and immuno-stimulatory activities. All species investigated were immuno-stimulatory with the strongest activity found in the hot water extracts of Laetiporus sp. and Phaeolepiota aurea. Anti-proliferative activity was primarily seen in the ethanol extracts of L. sp., P. aurea, Letharia vulpina, Vulpicida canadensis, and Hydnellum diabolus. Using Sevag extraction method, DEAE Sephadex anion-exchange and Sephacryl S-500 size-exclusion chromatography, an immuno-stimulatory compound was purified from the hot water extract of P. aurea. The purified compound, made up of carbohydrate and protein, has an average molecular weight of 390 kDa. Its carbohydrate component is rich in β-glucan. The compound can stimulate the innate immune system, causing a pro-inflammatory response. Further studies are required to characterize its carbohydrate and protein components in an effort to determine whether it is a novel immuno-stimulatory compound.