Lactarius hatsudake Tanaka is a mushroom recognized for its edible and medicinal properties. Previous research has demonstrated that polysaccharides extracted from Lactarius hatsudake Tanaka (LHP) exhibit direct inhibitory effects on liver cancer cells; however, the in vivo anticancer mechanisms remain inadequately understood. This study aims to further investigate the potential mechanisms of LHP against hepatocarcinoma by analyzing changes in immune response, gut microbiota, and serum metabolites. The results demonstrated that LHP markedly inhibited the growth of liver transplant tumors without inducing toxicity. Histological examination revealed that LHP significantly reversed the splenic index and safeguarded the intestinal mucosa in murine models. Flow cytometric analysis indicated that LHP enhanced the immune response within the tumor microenvironment by augmenting the CD8⁺/CD4⁺ T cell ratio, and forkhead box Protein 3 and interferon-gamma levels in both blood and tumor tissues. Additionally, microbiome analysis indicated that LHP positively modulated the gut microbial community structure, notably increasing the abundance of beneficial bacteria such as norank_f_Muribaculaceae, Dubosiella, Desulfovibrio, and Akkermansia, and suppressing the abundance of Helicobacter. Serum metabolome analysis revealed that LHP significantly up-regulated 16 metabolites and down-regulated 23 metabolites, predominantly through the modulation of lipid metabolic pathways. These results suggest that LHP has the potential to inhibit hepatocellular carcinoma growth by influencing tumor immunity and gut microbiota. These findings offer a theoretical basis for applying LHP in cancer-related foods and pharmaceuticals and propose novel approaches for utilizing natural resources in drug development and health promotion.

Edible mushroom polysaccharides demonstrate a range of bioactivities and have been investigated as potential adjuvant therapies for cancer treatment. Our prior research found Lactariks hatsudake Tanaka polysaccharide (LHP) effective against hepatocellular carcinoma, but the mechanisms remain unclear. This study aims to clarify the anti-cancer molecular mechanisms by examining the effects on specific signaling pathways through in vivo and in vitro analyses. Animal studies showed that LHP significantly inhibited the growth of transplanted liver cancer without toxicity. Histological and immunohistochemical analyses revealed that LHP increased nuclear cohesion in tumor cells and altered the expression of key regulatory proteins such as protein kinase B (Akt), nuclear factor κB (NF-κB), caspase-3, p21, and p53. These findings suggest that LHP's anticancer effects involve promoting apoptosis and disrupting the cell cycle. At the cellular level, assays such as 3-‍(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS), flow cytometry, and transwell invasion confirmed that LHP inhibited cancer cell proliferation and induced apoptosis. Polymerase chain reaction and Western blot assays revealed that LHP intervention reduced cyclin-dependent kinase 4 activity by upregulating p53 and p21, leading to cell cycle arrest and inhibited cell proliferation. LHP also promoted apoptosis by altering Bcl-2-associated X protein, B-cell lymphoma 2, and cleaved caspase-3 levels. Moreover, LHP could affect the Akt, NF-κB, and mitogen-activated protein kinase signaling pathways to exert anticancer effects. These findings underscore the potential of LHP as a novel and multifaceted therapeutic agent. Furthermore, the elucidation of LHP-related mechanisms offers a crucial theoretical foundation for developing innovative and effective treatments for hepatocellular carcinoma. Additionally, this supports its potential development as a functional food or adjuvant therapy for cancer, which holds significant implications and application prospects in both the food and medical fields.