Studies On The Inhibiting Tumor Effect Of D.Denneanum

The Chinese herb Dendrobium is prepared from the dried stems of Dendrobium species, and has used as a tonic. Modern medical research has showed that Dendrobium is a multifunctional herb. Its functions include prevention and cure of pearl eye, improvement of digestive system, inhibiting and preventing cancer, regulation of immune system and cure of Diabetes mellitus. The inhibitory effect on tumor effect of three extracts of D.denneanum was investigated in our study。D.denneanum polysaccharides was isolated and purified with water and ethanol. The results showed that the molecular average-weight(MW)of polysaccharides was 128912.The content of protein in polysaccharides was 0.111 percent. The optimum extraction was obtained by 300ml water per 50g, refluxing and extracting for 3 times, 1.5 hours each time. Inhibition of those three extracts on SMMC-7721 was determined with an MTT assay. The results showed that, 160μg/ml polysaccharides had a prominent inhibition on SMMC-7721 for 48 hours treatment, but inapparent inhibition on HL-7702. The transplantable models of S180 in mice were established to investigate the inhibitory effects of those three extracts against tumor. The drug treatment would last for 10 days. The main result indicated as follows: the weight of the mice treated by polysaccharides from D.denneanum was higher than the other mice .We can conclude from this results that polysaccharides would be benefit to mice growth. Polysaccharides from D.denneanum was effective on anticancer test in mice(P<0.05), especially with 0.625mg/ml polysaccharides. The spleen and thymus index of polysaccharides were higher than that of physiological salt solution group(P<0.01). SOD content of mouse blood serum in drug group was highly significantly higher than that of physiological salt solution group. MDA content of high concentration of polysaccharides group in mouse blood serum was significantly lower than that of physiological salt solution group(P<0.01). The result of tumor slice demonstrated that polysaccharides from D.denneanum could induce tumor apoptosis. In conclusion, polysaccharides is the major antineoplastic component in D.denneanum. It executes antineoplastic action by enhancing immunity function, improving antioxidation and inducing apoptosis. Our results showed that Dendrobium polysaccharides could be developmented to potential antineoplastic drug.