No abstract

Ganoderma lucidum, commonly referred to as Lingzhi, has been used in Asia for health promotion for centuries. The anti-cancer effects of G. lucidum have been demonstrated in both in vitro and in vivo studies. In addition, the observed anti-cancer activities of Ganoderma have prompted its usage by cancer patients alongside chemotherapy.The main two bioactive components of G. lucidum can be broadly grouped into triterpenes and polysaccharides. Despite triterpenes and polysaccharides being widely known as the major active ingredients, the different biological pathways by which they exert their anti-cancer effect remain poorly defined. Therefore, understanding the mechanisms of action may lead to more widespread use of Ganoderma as an anti-cancer agent.The aim of this paper is to summarise the various bioactive mechanisms that have been proposed for the anti-cancer properties of triterpenes and polysaccharides extracted from G. lucidum. A literature search of published papers on NCBI with keywords "Ganoderma" and "cancer" was performed. Among those, studies which specifically examined the anti-cancer activities of Ganoderma triterpenes and polysaccharides were selected to be included in this paper.We have found five potential mechanisms which are associated with the anti-cancer activities of Ganoderma triterpenes and three potential mechanisms for Ganoderma polysaccharides. In addition, G. lucidum has been used in combination with known anti-cancer agents to improve the anti-cancer efficacies. This suggests Ganoderma's bioactive pathways may compliment that of anti-cancer agents. In this paper we present several potential anti-cancer mechanisms of Ganoderma triterpenes and polysaccharides which can be used for the development of Ganoderma as an anti-cancer agent.

Background: Ganoderma lucidum is a type of fungus commonly consumed in Asia for the promotion of health and longevity. The observed biological activity of G. lucidum includes anti-cancer and anti-inflammatory effects which may be useful in the treatment and prevention of cancer and other chronic diseases. G. lucidum grows under conditions which range from tropical to temperate and has a different physiology depending on the geographical region in which it is grown. For this reason, the health benefits may vary depending on the form of G. lucidum and the environmental conditions to which it was exposed. This led us to investigate the effect of wildly grown G. lucidum, from the Himalayan region versus other commercially available G. lucidum products, on two human cancer cell lines.Methods: Extraction of the bioactive components found in G. lucidum is essential, as the fungus is tough and indigestible. Four different Ganoderma extracts were prepared. Thereafter, the extracts were tested on two human prostate cancer cell lines, and the IC 50 s were determined. This was followed by the use of Affymetrix GeneChip® PrimeView™ Human Gene Expression Arrays to identify the changes in gene expression due to the treatment of prostate cancer cell lines (PC3 and DU145) with Ganoderma extracts. Several key genes identified with Affymetrix analysis were validated using RT-PCR. Results and Discussion:We found that all the Ganoderma extracts showed growth inhibition in the cancer cell lines tested. Using Affymetrix microarray analysis, we identified four main biologically active pathways: cell cycle control/apoptosis, cell-cell adhesion, DNA repair, and inflammatory /immune response, where activity was influenced by the Ganoderma extracts used. Using RT-PCR, we tested ten genes associated with all four pathways. The RT-PCR results supported our findings in the Affymetrix analysis, i.e. that G. lucidum extracts have an anti-inflammatory and cell cycle effect and therefore may have long term health benefits. These effects were specific to the extract tested.