Growth-Inhibitory and Immunomodulatory Activities of Wild Mushrooms from North-Central British Columbia (Canada)

Abstract

Wild mushrooms, especially from North America, have not been systematically explored for their medicinal properties. Here we report screening for the growth-inhibitory and immunomodulatory activities of 12 species collected from multiple locations in north-central British Columbia, Canada. Mushrooms were characterized using morphology and DNA sequencing, followed by chemical extraction into 4 fractions using 80% ethanol, 50% methanol, water, and 5% sodium hydroxide. Growth-inhibitory, immunostimulatory, and anti-inflammatory activities of 5 mushrooms (Leucocybe connata, Trichaptum abietinum, Hydnellum sp., Gyromitra esculenta, and Hericium coralloides) are reported here, to our knowledge for the first time. Growth-inhibitory effects were assessed using the cytotoxic MTT assay. Immunostimulatory activity was assessed by tumor necrosis factor-α production in Raw 264.7 macrophages, whereas anti-inflammatory activity was assessed based on the inhibition of lipopolysaccharide-induced tumor necrosis factor-α production. The ethanol and aqueous extracts of Hydnellum sp. were potent growth inhibitors, with a half-maximal inhibitory concentration of 0.6 mg/mL. All 5 fungi displayed strong immunostimulatory activity, whereas only L. connata and T. abietinum showed strong anti-inflammatory activity. For the 7 other fungi investigated, which included well-known medicinal species such as Inonotus obliquus, Phellinus igniarius, and Ganoderma applanatum, the remarkable similarities in the biological activities reported here, and by others for specimens collected elsewhere, suggest that mushrooms can produce similar metabolites regardless of their habitat or ecosystem. This is to our knowledge the first study to explore wild mushrooms from British Columbia for biological activities that are relevant to cancer, and the results provide an initial framework for the selection of mushroom species with the potential for discovery of novel anticancer compounds.

Grifolin, neogrifolin and confluentin from the terricolous polypore Albatrellus flettii suppress KRAS expression in human colon cancer cells

“…Voucher specimens for these collections were deposited at the University of Northern British Columbia, Canada. The identity of A. flettii was confirmed using previously described genetic protocols [1,2,22]. The DNA sequence of collections CL128 and CL151 were identical and had highest sequence similarity to a collection of A. flettii GenBank JF899544.1 (99.82% identity/100% coverage).…”

“…Albatrellus flettii specimens were sequentially extracted with 80% ethanol, 50% methanol, water and 5% NaOH as previously described [1,2]. Solvents were completely removed by rotovap and powdered extracts were obtained by lyophilization.…”

“…There have been relatively few studies exploring the medicinal potential of compounds from wild mushrooms native to British Columbia (BC), Canada. Therefore, we have begun to study medicinal properties of selected native fungi, focusing on three bio-assays relevant to cancer: anti-cell viability, immuno-stimulatory and anti-inflammatory activities [1,2]. Screening over one hundred mushroom species occurring in north-central BC, we have documented that approximately 25% possess potent anti-cell viability activity.…”

Investigating British Columbia wild mushrooms for growth-inhibitory activity

“…At the outset of this research, it was hypothesized that wild mushrooms in Northern British Columbia contain compounds with potent bio-activities. The results from this study showed for the first time that indeed Northern BC is home to a large variety of mushrooms containing potent growth inhibitory compounds 97 . The extraction methods developed and adapted (using both the manual and speed extractor) during this study have laid the critical foundation for future mushroom research studies at UNBC and elsewhere.…”

Purification and characterization of an immuno-stimulatory compound from the water extract of royoporus badius (Pers.) A.B. De.

“…collected in the forest of British Columbia, whereby the structure of the compound was elucidated with the aid of both onedimensional (1-D) and two-dimensional (2-D) Nuclear Magnetic Resonance (NMR) along with Mass Spectrometry (MS) analysis; however, the bioactivity of the compound isolated was not described (Ming et al 2002). Later, Van et al (2009) (Smith et al, 2017). In addition, a growth-inhibitory polysaccharide (GIPinv) was successfully purified from Paxillus involutus (Batsch) Fr., a forest mushroom also found close to urban trees, which exerted potent growth-inhibitory activity against several cancer cell lines by inducing apoptosis in cancer cells (Barad et al, 2018).…”