Extracts of Daedaleopsis Confragosa F-1368 Inhibit In Vitro and In Vivo the Proliferation of Human Cancer Cells

The aim of this study was to evaluate the effects of two variants of the Daedaleopsis confragosa fungus extract, F-1368 strain, differing in polysaccharide concentration, on five human cancer cell lines (U-87 MG, C-33 A, SK-Mel-28, MDA-MB-231, SW620) in vitro. Standard cytotoxicity assessment methods, including MTT-assay and clonogenic assay, were employed. Additionally, an experiment was conducted on laboratory SCID mice with heterotopic xenografts of human glioblastoma U-87 MG, where the test preparations were administered subcutaneously into the tumor area. Tumor sizes were measured using a caliper, and upon euthanasia, xenografts were histologically examined with hematoxylin-eosin staining under a light microscope. Results from MTT and clonogenic assays demonstrated that F-1368 extracts reduced the viability, mitochondrial function, and proliferative activity of tumor cells in vitro. However, a threefold increase in polysaccharide concentration in one of the extracts did not significantly enhance its cytotoxicity against tumor cells in vitro. Furthermore, one extract was tested on U-87 MG cell xenografts, revealing a reduction in tumor growth in SCID mice. The maximum tumor growth inhibition index for U-87 MG cells reached 50.7% at 21 days post-commencement of extract injections. These findings suggest that the D. confragosa F-1368 strain holds promise for investigating both in vitro and in vivo models of antitumor activity and identifying potential bioactive molecules or compounds.