The Anti-tumor Effect And Mechanisms Of Pleurotus Citrinopileatus

Pleurotus citrinopileatus is the famous edible and medicinal mushroom in Changbai mountain. Pleurotus citrinopileatus grows fast and has short growth period,high output. Along with the continuous renewal of Pleurotus citrinopileatus cultivation technology, there are already large scale artificial cultivation in our province, which provides the material foundation for the development and utilization of Pleurotus citrinopileatus.Pleurotus citrinopileatus contains proteins, amino acids, vitamins and other nutrients, and can lower blood pressure, decrease blood lipid, resist oxidation, protect the liver, and so on. In recent years, some studies suggested Pleurotus citrinopileatus could inhibit the growth of S180 tumor, but had no direct toxicity to tumor cells in vitro. Other studies have shown that Pleurotus citrinopileatus polysaccharides injected into mice can increase the spleen weight with the increase of the dose, which suggested Pleurotus citrinopileatus could enhance the immune function in mice.Mechanism of natural anti-tumor drugs generally has two aspects: one is that it has cytotoxic activity against cancer cells; the other one is that it can suppress tumor indirectly through immunoregulation or inhibition of tumor metastasis.Based on the above background, the following questions are raised: 1. Can Pleurotus citrinopileatus suppress the growth of lung cancer? 2. If the answer is yes,does it suppress tumor through immunoregulation or through inducing apoptosis directly?So, our research included two parts and the results as follows:1. The anti-tumor effect and immunological mechanisms of Pleurotus citrinopileatus on the Lewis lung cancer miceIn order to investigate whether Pleurotus citrinopileatus has anti-tumor effect,Lewis lung cancer mice was established and treated with Pleurotus citrinopileatus i.g.The survival rate, body weight and tumor volume were regularly monitored.Phagocytosis percentage of peritoneal macrophages and T cell subsets ratio in splenocytes were deteced by FCM. Lewis/Yac-Ⅰ cells killing by splenocytes and proliferation of lymphocytes were detected by MTT. The results showed that the growth of Lewis lung cancer was suppressed. No effects were observed on phagocytosis percentage of peritoneal macrophages, T cell subsets ratio in splenocytes,Yac-Ⅰ cells killing by splenocytes and proliferation of lymphocytes. But Pleurotus citrinopileatus could increase Lewis cells killing by splenocytes. So Pleurotus citrinopileatus may suppress tumor growth by promoting the specific killing to Lewis cells of CD8+T cell.2. The anti-tumor effect and mechanisms of Pleurotus citrinopileatus in vitroFirstly, in order to investigate the immunological mechanisms of Pleurotus citrinopileatus’ anti-tumor effect in vitro, mice splenocytes were treated with Con A/LPS and Pleurotus citrinopileatus. The proliferation of splenocytes was detected by MTT. The results showed that Pleurotus citrinopileatus could not promote the proliferation of splenocytes.Then in order to investigate whether Pleurotus citrinopileatus can suppress tumor by inducing apoptosis directly, Lewis/A549 cells were treated with Pleurotus citrinopileatus. The proliferation of Lewis/A549 cells was detected by MTT. The cell cycle and apoptosis of Lewis/A549 cells were detected by FCM. The m RNA expression of apoptosis related genes were detected by RT-q PCR. Apoptosis related proteins were detected by western blotting. The results showed that Pleurotus citrinopileatus could inhibit the proliferation of Lewis/A549 cells and induced the early apoptosis of Lewis/A549 cells. Pleurotus citrinopileatus could increase cleaved caspase-3 and caspase-9 and reduce Bcl-2, those results therefore suggest that mitochondrial pathway is involved in the apoptosis induction of Pleurotus citrinopileatus.From the above studies the conclusions are:1. Pleurotus citrinopileatus can suppress Lewis lung cancer.2. The anti-tumor effect of Pleurotus citrinopileatus might through both promote the specific killing to Lewis cells of CD8+T cells and induce the apoptosis of lung cancer cells by increasing cleaved caspase-3 and caspase-9 and reducing Bcl-2.This study indicates that Pleurotus citrinopileatus has anti-tumor effect on Lewis lung cancer by inducing apoptosis of lung cancer cells through mitochondrial pathway. This study might provide experimental basis for the application of Pleurotus citrinopileatus.