A commercial nutraceutical mix Metabolic Cell-Support (MC-S[TM]) inhibits proliferation of cancer cell lines in vitro.

Background

Cancer is one of the leading causes of human disease related death in the world today (Gao 2005). The major methods for treating cancer include surgery, radiation, chemotherapy, and immunotherapy (Gao 2005, Gibbs 2000). Conventional cancer chemotherapy is used to kill or disable tumor cells while preserving the normal cells in the body by the application of synthetic compounds (Gao 2005, Fidler 2000). These agents have a narrow safety margin, and the therapy can fail due to drug resistance and dose limiting toxicities (Gao 2005). In Asia herbal preparations have been increasingly used for cancer therapy in an attempt to assist in the killing of tumor cells and to reduce the toxicity of combined chemotherapeutic agents (Gao 2005, Ho 2002, Tang 2003, Vickers 2002). Today many clinically effective anticancer drugs have been derived from natural sources, e.g. paclitaxel (Taxol) from Taxus brevifolia L. and vincristine (Oncovin) from Cantharanthus roseus G. Don (Pezzuto 1997). Plant and fungus extracts continue to offer a wide range of compounds with diverse structures and activity which will continue to occupy an important role in modern cancer treatments.

The medicinal properties of mushrooms and herbs have long been utilised in traditional medicine for healing and health. In the past decades scientific validation of the clinical efficacy of medicinal therapies has encouraged modern medicine to investigate the active ingredients of medicinal mushrooms and herbs. Unfortunately this approach may in some circumstances have resulted in products that have reduced functionality when compared with their natural sources (Borchers 2004). It is known that a range of active compounds found in medical mushrooms and herbs can stimulate the human immune system and/or inhibit tumor growth. As these compounds can vary in bioactivity and biospecificity, it may be possible to utilise a range of the compounds to symbiotically stimulate the immune system leading to a more efficacious response and inhibit tumor growth (Smith 2002).

The formulation of MC-S (Clinical Health Pty Ltd, Newcastle Australia) is based upon this principle and is composed of three medicinal mushrooms, Ganaderma lucidum, Lentinus edodes (mycelia) and Coriolus versicolor, a herb Astragalus membranaceous (from the root) and ascorbic acid. The individual components of this commercially available product have demonstrated immune stimulating potential and antitumor properties (Smith 2002, Monograph 2003).

Combined in its present formulation MC-S has been demonstrated to have a proliferative effect on PBLs in vitro (Clark 2007a) and reduced colds, flu and secondary infections in vivo (Clark 2007b).

Ganaderma Lucidum (lingzhi or reishi) is a highly regarded traditional Chinese medicine for enhancing the body's resistance to disease and consolidating the constitution of patients (Lin 2005). Studies on the polysaccharide extracts of Ganaderma lucidum, mainly in the form of (1?3)-[beta]-D-glucans, have demonstrated mitogenicity and activation of immune effector cells (Smith 2002, Zhou 2002) as well as a stimulating effect on the production of cytokines (Smith 2002, Goa 2004).

In vitro studies have also shown inhibitory effects on breast cancer cells (Sliva 2002, 2003, 2006, Hu 2002, Jiang 2006), prostate …