Ganoderma lucidum is a popular herbal medicine found in China to promote health. Modern research has disclosed that the active ingredients of Ganoderma can exhibit several effects, including antitumor effects and immunomodulation. The current study evaluated the antitumor effects of self-prepared Agaricus Blazei Extract and spores oil, and investigated the potential underlying mechanisms by observing the effects of the extracts and oil on topoisomerases and also the cell cycle. The results showed that Ganoderma extracts and spores oil presented dose-dependent inhibitory effects on tumor cells.
Ganoderma lucidum, also referred to as Ganoderma or Lingzhi, is among most often used fungi in Chinese medicine. Modern pharmacological and clinical studies have confirmed that Ganoderma contains abundant biologically active substances in their fruiting body, mycelia and spores, and possesses variable functions, including immunomodulation, anti-aging, reducing blood lipids, anti-viral and anti-tumor activities (1-6). The current study examined the antitumor activity of a combination of aqueous and ethanol extracts from the Ganoderma fruiting body and Ganoderma spores oil, which was extracted from broken spores by supercritical CO2 extraction technology and explored the possible underlying mechanisms. DNA topoisomerases certainly are a class of enzymes working in the regulating DNA supercoiling.
Topoisomerase overexpression has become associated with several human malignancies and is the objective for numerous chemotherapeutic agents (7). When topoisomerases are blocked, the cell encounters problems during transcription of the DNA and throughout cell division. The widely-used antitumor drug, campothecin, blocks the relaxing action of class I topoisomerases and induces significant G1 cell cycle arrest (8). A previous study indicated that the active elements of Ganoderma exhibited inhibition of topoisomerases (9). The present study examined whether Ganoderma extracts and spore oil affected the cell cycle and topoisomerases I and II.
Preparations of Ganoderma extracts and spores oil – Ganoderma extracts (GanoHerb™) and Ganoderma spores oil were provided by Fujian Xianzhilou Biological Science and Technology Co., Ltd. (Fuzhou, China). Ganoderma extract, a brown powder, was dissolved in double distilled water to prepare solutions of various concentrations, that were brown suspensions. Ganoderma spores oil had been a soft capsule with .5 g/.5 ml golden oil in each capsule. The stock solution of ganoderma lucidum spore oil were prepared using double distilled water that contained 6 µl/ml (v/v) Tween 80.
Recently, the impact of Ganoderma on tumors continues to be increasingly studied. The present study revealed that Ganoderma extracts and spores oil inhibited the growth of human leukemia cells (K562 and HL60) and human gastric carcinoma cells (SGC-7901) in a dose-dependent manner. In addition, Ganoderma extracts and spores significantly suppressed the development in the S180 and H22 transplant tumors in mice. Therefore, Ganoderma extracts and spores oil demonstrated definite antitumor effects in the in vitro vrlzqn in vivo studies.
Since the past, Ganoderma has been popular being a popular herbal medicine for that promotion of health (11). Numerous previous studies examined the immunomodulatory activities of Ganoderma (12,13). By detecting the immunity indexes of mice bearing S180 or H22 cells, Ganoderma extracts were concluded to possess a certain effect on improving immune function, while Ganoderma spores oil had no significant effect on the spleen or thymus indexes of mice. One of the primary aspects of Ganoderma extract is a polysaccharide that has been reported as immune function enhancer (12-15). As there were few polysaccharides (water-soluble substances) within the Ganoderma spores oil, the spores oil exhibited no evident effect on immunity. The current study also revealed that the antitumor results of Ganoderma may be safer in contrast to 5-FU, which led to the decreased weight and immunity indexes of mice (Tables I and ?andIIII).
To research the possible mechanism of ganoderma lucidum spore oil, the effects of extracts and spores oil on topoisomerases and also the effect of spores oil on the cell cycle were examined.
DNA topoisomerases really are a class of enzymes active in the regulating DNA supercoiling. Type I topoisomerases change the level of supercoiling of DNA by causing single-strand breaks and religation, whereas type II topoisomerases cause double-strand breaks. Those two activities are particularly crucial during DNA transcription and replication, when the DNA helix has to be unwound to enable proper purpose of large enzymatic machinery. Cancer chemotherapy uses this finding, using drugs that block topoisomerases to kill rapidly-dividing cancer cells. For example, the widely-used anthracycline drugs, including doxorubicin and daunorubicin, attack class II topoisomerases and the plant toxin, campothecin, blocks the relaxing action of class I topoisomerases.