Abstract
Ganoderma, highly ranked in Oriental traditional medicine, has been used as a remedy for many types of chronic diseases, including hepatopathy, type II diabetes, neurasthenia, hypertension, and cancer. Various polysaccharides (i.e., β-D-glucans and glycoproteins) and triterpenoids are the major active constituents present in Ganoderma. In vitro and animal studies have indicated that Ganoderma exhibits cancer-preventive and anticancer activity. Data from a clinical study in cancer patients showed Ganopoly, a crude Ganoderma polysaccharide extract, enhanced host immune function, including increased activity of effector cells such as T lymphocytes, macrophages, and natural killer cells, despite the lack of striking objective antitumor activity. Several clinical studies revealed that treatment of prostate cancer patients with the Ganoderma-containing PC-SPES (a mixture of eight herbal extracts) gave a significant decrease in the prostate-specific antigen levels, which compares favorably with second-line hormonal therapy that has agents such as estrogens and ketoconazole. Currently available data from numerous in vitro and in vivo studies suggest that the cancer-preventive and tumoricidal properties of Ganoderma might be ascribed to its antioxidative and radical-scavenging effects, enhancement of host immune function, induction of cell-cycle arrest and apoptosis, and other biological effects. Although Ganoderma may represent a practical and promising approach for cancer prevention and cancer treatment, further experimental, epidemiological, and clinical studies are needed to identify unrevealed molecular targets, resolve the relationship between Ganoderma intake and cancer risks, and explore the optimum dosing, efficacy, and safety, alone or in combination with chemotherapy/radiotherapy.